We provide chemical kinetics practice exercises, instructions, and a learning material that allows learners to study outside of the classroom. We focus on chemical kinetics skills mastery so, below you will get all questions that are also asking in the competition exam beside that classroom.
List of chemical kinetics Questions
Question No | Questions | Class |
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1 | The following graph represents the energy consumption of a reaction. What kind of change is it? A. Periodic change B. Physical change C. Endothermic reaction D. Exothermic reaction |
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2 | According to the Arrhenius equation, This question has multiple correct options A. A high activation energy usually implies a fast reaction. B. Rate constant increases with increase in temperature. This is due to a greater number of collisions whose energy exceeds the activation energy. C. Higher the magnitude of activation energy, stronger is the temperature dependence of the rate constant D. The pre-exponential factor is a measure of the rate at which collisions occur, irrespective of their energy. |
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3 | Rate constant k varies with temperature as given by equation: ( log kleft(min ^{-1}right)=5-frac{2000 K}{T} . ) We can conclude: This question has multiple correct options A. Pre-exponential factor A is 5. B. ( E_{a} ) is 2000 kcal. C. Pre-exponential factor A is ( 10^{5} ) D. ( E_{a} ) is 9.152 kcal |
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4 | Question 20. For the decomposition of azoisopropane to hexane and nitrogen at 543 K, the following data are obtained. Calculate the rate constant. t(s) p(mm of Hg) 35.0 360 54.0 720 63.0 0 2.303 lo Use the relation k=- to calculate rate constants and 2p, -PU) then find average rate constant. |
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5 | A radioactive isotope ( boldsymbol{X} ) with half life of ( 1.37 times 10^{9} ) years decays to ( Y, ) which is stable. A sample of rock from moon was found to contain both the elements ( boldsymbol{X} ) and ( Y ) in the ratio ( 1: 7 . ) What is the age of the rock? |
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6 | For gaseous reaction, rate ( boldsymbol{k}[boldsymbol{A}][boldsymbol{B}] . ) If volume of container is reduced to ( 1 / 4 ) of initial, then the rate of reaction will be times of initial. A . ( 1 / 8 ) B. 8 c. ( 1 / 16 ) D. 16 |
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7 | ( 80 % ) of a first order reaction was completed in 70 min. How much it will take for ( 90 % ) completion of a reaction? A. 100 min B. 110 min c. ( 120 mathrm{min} ) D. None of these |
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8 | For the reaction: ( boldsymbol{H}_{2}+boldsymbol{C l}_{2} stackrel{text {sunlight}}{longrightarrow} mathbf{2} boldsymbol{H} boldsymbol{C l} ) the order of reaction is : ( mathbf{A} cdot mathbf{0} ) B. 2 c. 1 D. 3 |
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9 | For the following reactions,write the rate of reaction expression in terms of reactants and products? ¡) ( mathbf{4} boldsymbol{N} boldsymbol{H}_{3}(boldsymbol{g})+mathbf{5} mathbf{0}_{2}(boldsymbol{g}) longrightarrow mathbf{4} boldsymbol{N} boldsymbol{O}(boldsymbol{g})+ ) ( mathbf{6} boldsymbol{H}_{2} boldsymbol{O}(boldsymbol{g}) ) ii) ( left.2 N_{2} O_{5}right) longrightarrow 2 N O_{2}+O_{2} ) |
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10 | If the initial concentration is reduced to ( 1 / 4 ) th in a zero order reaction, then the time taken for half the reaction to complete: A. remains same B. becomes 4 times c. becomes one-fourth D. doubles |
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11 | For first order reaction as time duration goes from 10 in to 30min rate of reaction decreases from ( 0.4 M s^{-1} ) to ( 0.04 M s^{-1} ) What is the half life of the reaction? ( A cdot 8 min ) B. 4 min c. 6 min D. 2 min |
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12 | Q Type your question ( A ) B. ( c ) ( D ) |
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13 | For a reaction ( boldsymbol{X} longrightarrow boldsymbol{Y}, ) the graph of the product concentration (x) versus time (t) came out to be straight line passing through the origin. Hence the ( operatorname{graph} ) of ( frac{-boldsymbol{d}[boldsymbol{X}]}{boldsymbol{d} boldsymbol{t}} ) and time would be: A. straight line with a negative slope and an intercept on y-axis B. straight line with positive slope and an intercept on ( y ) axis c. a straight line parallel to x-axiss D. a hyperbola |
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14 | What is the rate of the reaction for ( mathbf{2 A} rightarrow boldsymbol{B} ? ) ( ^{mathrm{A}} cdot-frac{1}{2}left[frac{d[A]}{d t}right] ) в. ( -frac{d[A]}{d t} ) c. ( -frac{d[B]}{d t} ) D. ( +frac{d[A]}{d t} ) |
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15 | At ( 400 mathrm{K}, ) the half-life of a sample of a gaseous compound initially at 56.0 ( k P a ) is 340 s. When the pressure is 28.0 ( k P a, ) the half-life is 170 s. The order of the reaction is: A. 0 B. 2 ( c ) D. ( 1 / 2 ) |
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16 | At room temperature ( left(20^{circ} mathrm{C}right) ) orange juice gets spoilt in about 64 hours. In a refrigerator at ( 3^{circ} C ) juice can be stored three times as long before it gets spoilt. The activation energy of the reaction that causes the spoiling of juice is : A ( .43 .46 mathrm{kJmol}^{-1} ) B . ( 46.76 mathrm{kJmol}^{-1} ) c. ( 49.54 mathrm{kJmol}^{-1} ) D. 50.23 kJmol( ^{-1} ) |
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17 | LLOS iction given in same item .83 Match the graph given in Column I with the order of reaction Column II. More than one item in Column 1 may link to the same ita Column II. Column Column II Rale- Concentration- First order Rate Concentration- 2 Zero order Concentration Time log (Conc) – Time- |
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18 | Which equation is the most appropriate to calculate the energy of activation, if the rate of reaction is doubled by increasing temperature from ( boldsymbol{T}_{1} boldsymbol{K} ) to ( T_{2} K ? ) ( ^{mathbf{A}} cdot log _{10}left(frac{k_{1}}{k_{2}}right)=frac{E_{a}}{2.303 R}left[frac{1}{T_{1}}-frac{1}{T_{2}}right] ) B. ( log _{10}left(frac{k_{2}}{k_{1}}right)=frac{E_{a}}{2.303 R}left[frac{1}{T_{2}}-frac{1}{T_{1}}right] ) ( ^{mathbf{C}} cdot log _{10} frac{1}{2}=frac{E_{a}}{2.303}left[frac{1}{T_{2}}-frac{1}{T_{1}}right] ) D ( cdot log _{10} 2=frac{E_{a}}{2.303 R}left[frac{1}{T_{1}}-frac{1}{T_{2}}right] ) |
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19 | ( 90 % ) of a first order reaction was completed in 100 min. What is the half life of the reaction? ( A cdot 63.3 min ) B. 53.3 min c. 43.3 min D. 30 min |
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20 | The rate of the reaction: ( boldsymbol{C H}_{3} boldsymbol{C O O C}_{2} boldsymbol{H}_{5}+boldsymbol{N a O H} rightarrow ) ( boldsymbol{C H}_{3} boldsymbol{C O O N a}+boldsymbol{C}_{2} boldsymbol{H}_{5} boldsymbol{O H} ) is given by the equation, rate( =boldsymbol{k}left[boldsymbol{C H}_{3} boldsymbol{C O O C}_{2} boldsymbol{H}_{5}right][boldsymbol{N a O H}] ) If concentration is expressed in ( m o l / L ) the units of ( k ) are: A ( cdot m o l^{-2} L^{2} s^{-1} ) B . ( operatorname{molL}^{2} s^{-1} ) c. ( L m o l^{-1} s^{-1} ) D. ( s^{-1} ) |
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21 | To initiate a reaction, minimum energy which is required to break bonds is called bond energy activation energy breaking energy ionization energy A. B. 2 ( c cdot 3 ) ( D ) |
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22 | In a reaction between two gaseous reactants the number of binary collisions per second (Z) is given by: A ( cdot Z=pi sigma_{A-B}^{2} sqrt{frac{8 K T}{pi mu}} n_{A} cdot n_{B} ) В . ( Z=pi sigma_{A-B} sqrt{frac{8 K T}{pi mu}} ) c. ( Z=sigma_{A-B}^{2} sqrt{frac{8 K T}{pi mu}} n_{A} . n_{B} ) D ( cdot Z=sigma_{A-B} sqrt{frac{8 K T}{pi mu}} n_{A} cdot n_{B} ) |
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23 | Two chemical reactions are given: i. Sulphur dioxide combines with oxygen to form sulphur trioxide. ii. Sodium reacts with water (a) Write the balanced chemical equation for any one of the above reactions. (b) Which of the above reactions is a reversible reaction? (c) What is the effect of pressure and temperature on this reversible reaction? Give reason |
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24 | The van’t Hoff factor of ( B a C l_{2} ) at ( 0.01 mathrm{M} ) concentration is ( 1.98 . ) The percentage of dissociation of ( B a C l_{2} ) at this concentration is: A .49 B. 69 ( c cdot 89 ) D. 100 |
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25 | At what time, there will be 6400 bacteria in the flask? A. ( 150 mathrm{min} ) B. 90 min c. ( 160 min ) D. ( 120 mathrm{min} ) |
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26 | A two-step mechanism has been suggested for the reaction of nitric oxide and bromine. ( N O(g)+B r_{2}(g) stackrel{K_{1}}{longrightarrow} N O B r_{2}(g) ) ( N O B r_{2}(g)+N O(g) stackrel{K_{2}}{longrightarrow} 2 N O B r(g) ) The observed rate law is, rate ( = ) ( boldsymbol{k}[boldsymbol{N} boldsymbol{O}]^{2}left[boldsymbol{B} boldsymbol{r}_{2}right] . ) Hence, the rate determining step is : A ( cdot N O(g)+B r_{2}(g) rightarrow N O B r_{2}(g) ) в. ( N O B r_{2}(g)+N O(g) rightarrow 2 N O B r(g) ) c. ( 2 N O(g)+B r_{2}(g) rightarrow 2 N O B r(g) ) D. none of these |
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27 | The specific rate constant of the decomposition of ( N_{2} O_{5} ) is ( 0.008 m i n^{-1} ) The volume of ( O_{2} ) collected after 20 minute is ( 16 mathrm{mL} ). The volume in ( mathrm{ml} ) that would be collected at the end of reaction. ( N O_{2} ) formed is dissolved in ( boldsymbol{C C l}_{4} ) is |
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28 | Reaction ( boldsymbol{A}+boldsymbol{B} longrightarrow boldsymbol{C}+boldsymbol{D} ) follow’s following rate law rate ( =boldsymbol{k}=[boldsymbol{A}]^{frac{1}{2}}[boldsymbol{B}]^{frac{1}{2}} ) Starting with initial conc. of one mole of ( A ) and ( B ) each, what is the time taken for amount of A of become 0.25 mole. Given ( k=2.31 times 10^{-3} s e c^{-1} . ) (in sec). (Answer in the form of ( 100 x ) ) |
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29 | Write any two characteristics of first order reaction. |
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30 | Sucrose decomposes in acid solution into glucose and fructose according to first order rate law with ( t_{1 / 2}=3 ) Hrs. What fraction of the sample of sucrose remains after 8 hours? |
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31 | For the reaction2 ( boldsymbol{A}+boldsymbol{B} rightarrow boldsymbol{A}_{2} boldsymbol{B} ) rate ( = ) ( boldsymbol{k}[boldsymbol{A}][boldsymbol{B}]^{2} ) with ( boldsymbol{k}=boldsymbol{2} . boldsymbol{0} times ) ( 10^{-6} m o l^{-2} L^{2} s^{-1}, ) what is the rate of the reaction when ( [mathrm{A}] ) is reduced to 0.060 molL’-13. the initial rate of reaction when ( [A]=0.1 m o l L^{-1} a n d[B]= ) ( 0.2 m o l L^{-1} i s 8 times 10^{-9} m o l L^{-1} s^{-1} ) |
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32 | For the following reaction at a particular temperature, according to the equations ( mathbf{2} N_{2} boldsymbol{O}_{mathbf{5}} rightarrow mathbf{4} boldsymbol{N} boldsymbol{O}_{2}+boldsymbol{O}_{2} ) ( 2 N O_{2}+frac{1}{2} O_{2} rightarrow N_{2} O_{5} ) ( A cdot E_{1}>E_{2} ) в. ( E_{1}<E_{2} ) C. ( E_{1}=2 E_{2} ) D. ( sqrt{E_{1} E_{2}^{2}}=1 ) |
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33 | Let there be as first-order reaction of the type, ( boldsymbol{A} rightarrow boldsymbol{B}+boldsymbol{C} ). Let us assume that only ( A ) is gaseous. We are required to calculate the value of rate constant based on the following date. [ begin{array}{lcc} text { Time } & text { o } & text { T } \ text { Partial pressure of A } & P_{0} & P_{t} end{array} ] Calculate the expression of rate constant. A ( cdot k=frac{1}{t} ln left(frac{P_{0}}{T_{l}}right) ) B . ( k=frac{1}{t} ln left(frac{P_{t}}{T_{D}}right) ) C . ( k=frac{1}{t} ln left(frac{2 P_{0}}{P_{t}}right) ) D・ ( k=frac{1}{t} ln left(frac{P_{F}}{2 P_{0}}right) ) |
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34 | The rate of a reaction expressed in terms of change in concentration of reactants at two different times, that is the average rate in terms of reactants, can be written as ? This question has multiple correct options A ( cdot frac{x_{2}-x_{1}}{t_{2}-t_{1}} ) B. ( +Delta x / Delta t ) c. ( -frac{x_{2}-x_{1}}{t_{2}-t_{1}} ) D. ( -Delta x / Delta t ) |
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35 | Question 21. All energetically effective collisions do not results in a chemical change. Explain with the help of an example. |
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36 | What happen with the rate of the reaction when the frequency and the number of effective collisions between reacting particles increases? A. Increases B. Decreases c. Remains the same D. Approaches zero E. None of the above |
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37 | A hypothetical reaction ( boldsymbol{A}_{2}+boldsymbol{B}_{2} rightarrow ) ( 2 A B ) follows the mechanism as given below: ( boldsymbol{A}_{2} rightleftharpoons boldsymbol{A}+boldsymbol{A} quad(text { fast }) ) ( boldsymbol{A}+boldsymbol{B}_{2} rightarrow boldsymbol{A} boldsymbol{B}+boldsymbol{B} quad(text { slow }) ) ( A+B rightarrow A B quad(f a s t) ) The order of the overall reaction is: ( A cdot 2 ) B. c. 1.5 D. |
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38 | Nitrogen dioxide ( left(N O_{2}right) ) dissociates into nitric oxide ( (N O) ) and oxygen ( left(O_{2}right) ) as follows: ( 2 N O_{2} rightarrow 2 N O+O_{2} ) If the rate of decrease of concentration of ( N O_{2} ) is ( 6.0 times 10^{-12} ) mol ( L^{-1} s^{-1} ) What will be the rate of increase of concentration of ( O_{2} ? ) В. ( 6 times 10^{-12} ) mol ( L^{-1} s^{-1} ) D. ( 1.5 times 10^{-12} ) mol ( L^{-1} s^{-1} ) |
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39 | Question 22. What happens to most probable kinetic energy and the energy of activation with increase in temperature? |
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40 | For a unimolecular reaction: A. The order and molecularity of the slowest step are equal to one B. Molecularity of the reaction can be zero, one or two C. More than one reacting species are involved in one step D. Molecularity of the reaction can be determined only experimentally |
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41 | First order reaction completes ( 20 % ) in 5 min. How much time it will take for ( 60 % ) completion? A . 26.5 min B . 20.5 min c. ( 19.5 mathrm{min} ) D. 18 min |
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42 | A graph of concentration versus time data for a first-order reaction gives a straight line in which of the following plots of the data? A ( cdot[A]_{t}=-k t+[A]_{0} ) B ( cdot ln [A]_{t}=-k t+ln [A]_{0} ) c. ( frac{1}{[A]_{t}}=k t+frac{1}{[A]_{0}} ) D. All of the above E. None of the above |
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43 | From the following data estimate the order for decomposition of an aqueous solution of hydrogen peroxide: Time ( quad ) o ( quad mathbf{1 0} quad mathbf{2 0} ) (minutes) [ V(m l) ] ( begin{array}{lll}46.1 & 29.8 & 19.6end{array} ) where ( V ) is the volume of potassium permanganate solution in ( m L ) required to decompose a definite volume of the peroxide solution. A . B. 1 ( c cdot 2 ) D. ( 1 / 2 ) |
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44 | The excess energy which a molecule must posses to become active is known as: A. kinetic energy B. threshold energy c. potential energy D. activation energy |
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45 | The rate of reaction between ( A ) and ( B ) increases by a factor of ( 100, ) when the concentration of ( A ) is increased 10 folds. The order of reaction with respect to ( boldsymbol{A} ) is: A . 10 B. 2 ( c cdot 1 ) D. 20 |
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46 | Energy produced in a chemical reaction is a specific type of : A. kinetic energy B. elastic energy c. potential energy D. entropy E. thermal energy |
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47 | Which of the following represents the expression for ( frac{3}{4} ) th life of first order reaction? ( ^{mathrm{A}} cdot frac{2.303}{k} log 4 / 3 ) в. ( frac{2.303}{k} log 3 / 4 ) c. ( frac{2.303}{k} log 4 ) D. ( frac{2.303}{k} log 3 ) |
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48 | Assertion Molecularity greater than three is not observed. Reason The overall molecularity of a complex reaction is equal to molecularity of the Slowest step. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion C. Assertion is correct but Reason is incorrect D. Both Assertion and Reason are incorrect |
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49 | What is activation energy? | 12 |
50 | The rate of reaction ( A+B rightarrow ) Products is given by the equation ( r=k[A][B] . ) If ( B ) is taken in large excess the order of the reaction would be : | 12 |
51 | Statement 1: In a zero order reaction, if the concentration of the reactant is doubled, the half-life period is also doubled. Statement 2: For a zero-order reaction, the rate of the reaction is independent of initial concentration. A. Statement 1 is True, statement 2 is True, statement 2 is a correct explanation of statement 1. B. Statement 1 is True, statement 2 is True, statement 2 is not a correct explanation of statement 1 c. Statement 1 is true, Statement 2 is False D. Statement 1 is False, Statement 2 is True. |
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52 | The unit of rate constant for zero order reaction is: A ( cdot s^{-1} ) B ( cdot operatorname{mol} L^{-1} s^{-1} ) c. ( L m o l^{-1} s^{-1} ) D. ( L^{2} m o l^{-2} s^{-1} ) |
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53 | The rate of reaction does not depend upon A. Temperature B. Concentration c. catalyst D. None of these |
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54 | Assume that,in a chemical reaction a certain subtance decompses at rate proportional to the amount present in 5 hours intial quantity of 10,000 gram reduced to 1000 gram. how much will left of an initial quantity of 20,000 gram after 15 hours rm? |
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55 | Assertion For the reaction ( R C l+N a O H(a q) rightarrow ) ROH ( + ) Na ( C l ), the rate of reaction is reduced to half on reducing the concentration of RCl to half. Reason The rate of the reaction is represented by k[RCl], i.e., it is a first order reaction. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion C. Assertion is correct but Reason is incorrect D. Assertion is incorrect but Reason is correct |
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56 | The reaction between ( A ) and ( B ) is first order with respect to A and zero order with respect to B. Fill in the blanks in the following table: ( begin{array}{lll}text { Experiment } & {[boldsymbol{A}] / boldsymbol{m o l} boldsymbol{L}^{-1}} & boldsymbol{B}] / boldsymbol{m o l} boldsymbol{L}^{-1} \ 1 & 0.1 & 0.1 \ 11 & – & 0.2 \ 111 & 0.4 & 0.4 \ & & \ & & \ & & \ & & \ & & end{array} ) |
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57 | In a reaction ( 5 g ) ethyl acetate is hydrolysed per litre in presence of dilute ( H C l ) in 300 min. If the reaction is of the first order and initial concentration is ( 22 g / L, ) calculate the rate constant for the reaction. |
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58 | A tangent drawn on the curve obtained by plotting concentration of product mole ( L^{-1} ) ) of the first-order reaction vs time (min) at the point corresponding to time minute takes an angle to ( 30^{circ} ) with concentration axis Hence the rate of formations of product after 20 minutes will be: A. 0.580 mole ( L^{-1} ) min ( ^{-1} ) B. 1.723 mole ( L^{-1} ) min ( ^{-1} ) c. 0.290 mole ( L^{-1} ) min ( ^{-1} ) D. 0.866 mole ( L^{-1} ) min ( ^{-1} ) |
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59 | A first-order reaction is ( 50 % ) completed in 20 minutes at ( 27^{0} ) C and in 5 min at ( 47^{0} mathrm{C} . ) The energy of activation of the reaction is : A. ( 43.85 k J / ) mol в. ( 55.33 k J / ) mol c. ( 11.97 k J / ) mol D. ( 6.65 k J / ) mol |
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60 | The reaction between ( N O ) and ( C l_{2} ) takes place in the following two steps: ( boldsymbol{I} cdot boldsymbol{N} boldsymbol{O}+boldsymbol{C l}_{2}_{k_{2} atop f a t}^{k_{1}} boldsymbol{N O C l}_{2} ) II. ( N O C l_{2}+N O frac{k_{3}}{s l o w} geq 2 N O C l ) The rate law of overall reaction, ( 2 N O+ ) ( C l_{2} longrightarrow 2 N O C l, ) can be given by: A ( cdot ) Rate ( =k[N O]^{2}left[C l_{2}right] ) B・Rate ( =k[N O]left[C l_{2}right] ) c. Rate ( =k[N O C l][N O ) D・Rate ( =k[N O]left[C l_{2}right]^{2} ) |
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61 | The rate constant for a recation is ( 10.8 times 10^{-5} ) mol ( L^{-1} S^{-1} . ) The reaction obeys: A. First order B. Zero order c. second order D. All are wrong |
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62 | Assertion: Increasing the temperature increases the reaction rate. Reason: At high temperatures, molecules or atoms tend to be further apart. A. Both Assertion and Reason are true and Reason is the correct explanation of Assertion B. Both Assertion and Reason are true but Reason is not the correct explanation of Assertion c. Assertion is true but Reason is false D. Assertion is false but Reason is true E. Both Assertion and Reason are false |
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63 | For the reaction ( 4 N H_{3}+5 O_{2} rightarrow ) ( 4 N O+6 H_{2} O, ) the rate of reaction with respect to ( N H_{3} ) is ( 2 x 10^{-3} M s^{-1} . . ) Find the rate of the reaction with respect to oxygen in ( M s^{-1} ) |
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64 | What does it mean when a collision is elastic? A. No energy is gained or lost. B. Energy is gained c. Energy is lost D. The particles can stretch out. E. The particles slow down |
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65 | While plotting decrease in mass against time, a flat curve shows: A. fastest reaction B. reaction is slower c. reaction is over. D. None of these. |
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66 | 0.9 Which of the following statements is not correct about order of a reaction? (a) The order of a reaction can be a fractional number (b) Order of a reaction is experimentally determined quantity (c) The order of a reaction is always equal to the sum of the stoichiometric coefficients of reactants in the balanced chemical equation for a reaction (d) The order of a reaction is the sum of the powers of molar concentration of the reactants in the rate law expression |
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67 | The time required for ( 100 % ) completion of a zero order reaction is: ( mathbf{A} cdot a k ) в. ( frac{a}{2 k} ) c. ( frac{a}{k} ) D. ( frac{2 k}{a} ) |
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68 | Observation Time (in ( quad boldsymbol{P}_{boldsymbol{x}} ) (in ( mathrm{mm} ) minute) ( quad ) of ( mathrm{Hg} ) 800 00 to At constant temperature and volume ( boldsymbol{X} ) [ text { decomposes as } 2 mathrm{X}(mathrm{g}) rightarrow 3 mathrm{Y}(mathrm{g})+ ] ( 2 mathrm{Z}(mathrm{g}), ) where ( mathrm{P}_{x} ) is the partial pressure of ( X . ) What is the order of reaction with respect to ( X ? ) (i) Find the rate constant. (ii) Find the time for ( 75 % ) completion of the reaction. (iii) Find total pressure when pressure of ( X ) is ( 700 mathrm{mm} ) of Hg. |
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69 | Consider the following elementary reaction [ mathbf{2 A}+boldsymbol{B}+boldsymbol{C} rightarrow boldsymbol{text {Products.}} ] All reactant are present in the gaseous state and reactant ( C ) is taken in excess. What is the unit of rate constant of the reaction? ( mathbf{A} cdot operatorname{mol} L^{-1} operatorname{tim} e^{-1} ) B. ( operatorname{time}^{-1} ) ( mathbf{c} cdot m o l^{-1} L^{2} operatorname{time}^{-1} ) D. ( m o l^{-2} L^{2} )time( ^{-1} ) |
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70 | ( boldsymbol{S} boldsymbol{O}_{2} boldsymbol{C l}_{2}(boldsymbol{g}) rightarrow boldsymbol{S} boldsymbol{O}_{2}(boldsymbol{g}) ) The given reaction is a first order gas reaction with ( k=2.2 times 10^{-5} s e c^{-1} ) at ( 320^{circ} mathrm{C} . ) What ( % ) of ( S O_{2} C l_{2} ) is decomposed on heating this gas for 90 ( min ? ) ( mathbf{A} cdot 11.2 % ) B . 12.3% c. ( 13.4 % ) D. 14.5% |
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71 | A first order reaction is half-completed in 45 minutes. How long does it need for ( 99.9 % ) of the reaction to be completed? ( A cdot 20 ) hours B. 10 hours c. ( 7 frac{3}{10} ) hours D. 5 hours |
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72 | The gaseous reaction ( A_{2} rightarrow 2 A ) is first order in ( A_{2} . ) After 12.3 minutes ( 65 % ) of ( A_{2} ) remains undecompensed. ( 90 % ) of ( A_{2} ) ? What is the half life of the reaction? |
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73 | In hypothetical reaction, ( boldsymbol{A}_{2}+boldsymbol{B}_{2} longrightarrow ) ( 2 A B, ) follows the mechanism as given below: ( A_{2} rightleftharpoons A+A quad ) (fast reaction) ( A+B_{2} longrightarrow A B+B quad ) (slow reaction) ( A+B longrightarrow A B quad ) (fast reaction) Give the rate law and order of reaction. |
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74 | If ( boldsymbol{r}=-frac{mathbf{3}}{mathbf{2}} frac{boldsymbol{Delta}[boldsymbol{A}]}{boldsymbol{Delta} boldsymbol{t}}=-mathbf{5} frac{boldsymbol{Delta}[boldsymbol{B}]}{boldsymbol{Delta} boldsymbol{t}}=+frac{boldsymbol{7}}{boldsymbol{3}} frac{[boldsymbol{Delta} boldsymbol{C}]}{Delta boldsymbol{t}} ) which of the following is the corresponding stoichiometric equation? ( ^{mathbf{A}} cdot frac{2}{3} A+frac{1}{5} B rightarrow frac{3}{7} C ) в. ( frac{2}{3} A+frac{5}{2} B rightarrow frac{7}{3} C ) c. ( frac{3}{2} A+frac{5}{2} B rightarrow frac{7}{3} C ) D ( cdot frac{7}{3} C+frac{5}{2} B rightarrow frac{3}{2} A ) |
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75 | For a gaseous reaction the rate equation is ( boldsymbol{v}=boldsymbol{k}[boldsymbol{A}][boldsymbol{B}] . ) If the volume of the gaseous system is suddenly reduced to ( 1 / 3 ) of initial volume. The rate would become: A. ( 1 / 9 ) times B. 9 times c. ( 1 / 6 ) times D. 6 times |
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76 | Higher order ( (>3) ) reactions are rare due to: A. low probability of simultaneous collision of all the reacting species B. increase in entropy and activation energy as more molecules are involved C. shifting of equilibrium towards reactants due to elastic collisions D. loss of active species on collision |
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77 | At room temperature, the reaction between ( N O ) and ( O_{2} ) to give ( N O_{2} ) is fast, while that between ( C O ) and ( O_{2} ) is slow. It is due to: A. ( mathrm{CO} ) is smaller in size than that of ( mathrm{NO} ) B. ( mathrm{CO} ) is poisonous C. the activation energy for the reaction, ( 2 N O+O_{2} rightarrow ) ( 2 N O_{2} ) is less than ( 2 C O+O_{2} rightarrow 2 C O_{2} ) D. none of the above |
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78 | (th) The collision must be effective Q. 16 A first order reaction is 50% completed reaction is 50% completed in 1.26 X 1014 s. How much time would it take for 100% completion? (a) 1.26 x 1015 s (b) 2.52 x 1014 s (c) 2.52 x 1028 (d) Infinite |
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79 | The decomposition of ( N H_{3} ) gas on a heated tungsten surface gave the following results: Initial pressure ( quad 65 quad 105 ) (mm of ( boldsymbol{H} boldsymbol{g} ) Half-life ( begin{array}{ll}290 & x=670end{array} ) ( (mathrm{sec}) ) Calculate approximately the values of ( x ) and ( y ) |
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80 | The reaction ( boldsymbol{C} boldsymbol{H}_{3}-boldsymbol{C H}_{2}-boldsymbol{N} boldsymbol{O}_{2}+ ) ( boldsymbol{O H}^{-} longrightarrow boldsymbol{C H}_{3}-stackrel{oplus}{boldsymbol{C} boldsymbol{H}}-boldsymbol{N} boldsymbol{O}_{2}+boldsymbol{H}_{2} boldsymbol{O} ) obeys the rate law for pseudo first order kinetics in the presence of a large excess of hydroxide ion. If ( 1 % ) of nitro ethane undergoes reaction is half a minute when the reactant concentration is ( 0.002 M . ) What is the pseudo first order rate constant? ( (log 99=1.996) ) |
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81 | A substance reacts with initial concentration of ( a ) mol ( d m^{-3} ) according to zero order kinetics. The time it takes for the completion of the reaction is: ( k= ) rate constant A ( cdot frac{k}{a} ) в. ( frac{a}{2 k} ) c. ( frac{a}{k} ) D. ( frac{2 k}{a} ) |
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82 | For a reaction ( boldsymbol{A}+boldsymbol{B} rightarrow ) Products, it is observed that doubling the concentration of ( B ) caused the reaction rate to increase four times, but doubling the concentration of ( A ) has no effect on the rate of reaction. The rate equation is therefore: A ( cdot ) rate ( =K[A]^{2} ) B . rate = ( K[B]^{2} ) c. rate ( =K[A][B] ) D. rate = ( K[A] ) |
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83 | In the pressence of a catalyst, the activation energy of a reaction is lowered by ( 2 k c a l ) at ( 27^{circ} C . ) The rate of reaction will increase by: ( (text {Antilog} 1.43=28) ) A. 2 times B. 14 times c. 28 times D. 20 times |
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84 | Speed of a chemical reaction increases with ( _{-}–_{-}-_{-}-_{-}-_{-} ) in temperature A. decreases B. increases c. no change D. can’t say |
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85 | Arhenius equation is not applicable for: A . first order reactions B. second order reactions c. zero order reaction D. radioactive decay |
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86 | .48 Thermodynamic feasibility of the reaction alone cannot decide the rate of the reaction. Explain with the help of one example. |
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87 | Write definition of molecularity of reaction. |
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88 | Which one of the following is true for an exothermic reaction ( boldsymbol{A} rightleftharpoons boldsymbol{B} . ) If ( boldsymbol{E}_{f} ) and ( E_{b} ) are the activation energies of forward and backward reactions respectively? ( mathbf{A} cdot E_{f}>E_{b} ) B . ( E_{f}=E_{b} ) ( mathbf{c} cdot E_{f}=-E_{b} ) D ( cdot E_{f}<E_{b} ) |
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89 | Q. 52 Why can we not determine the order of a reaction by taking consideration the balanced chemical equation? Collowing |
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90 | Which of the following statements regarding molecularity of the reaction is wrong? A. It may be either whole number or fractional. B. It is calculated from the reaction mechanism. c. It depends on the rate determining step. D. It is number of molecules of reactants taking part in a single step chemical reaction |
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91 | Order of rate of reaction with ( A g N O_{3} ) or rate of ( boldsymbol{S}_{N} mathbf{1} ) is: A . ।>III>II B. ||>|||>| c. ।>II>III D. III>>>II |
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92 | A reaction is ( 50 % ) complete in 2 hours and ( 75 % ) complete in 4 hours. The order of reaction is: A. B. ( c cdot 2 ) D. |
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93 | Question 5. In a reaction if the concentration of reactant A is tripled, the rate of reaction becomes twenty seven times. What is the order of the reaction? |
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94 | If the concentration of the reactants in the reaction ( 2 A+B rightarrow C+D ) is increased by three folds, the rate of the reaction will be increased by: A. 27 times B. 9 times c. 64 times D. 01 times |
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95 | The rate of the chemical reaction doubles for and an increase of ( 10 K ) in absolute temperature from ( 298 K ) Calculate ( boldsymbol{E}_{boldsymbol{a}} ) |
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96 | Question 4. The conversion of molecules x to y follows second order kinetics. If concentration of x is increased to three times how will it affect the rate of formation of y? For II order kinetics, rate = k (reactant]? So make two equation first by taking initial rate and concentration, second by taking tripled concentration and unknown rate (r’). Compare them to find a relation between randr! |
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97 | What is slow and fast reaction? Give example. |
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98 | The unit of zero order rate constant is: A . litre mol” ( sec ^{-1} ) B. mol liitre ( ^{-1} )sec( ^{-1} ) ( mathbf{c} cdot sec ^{-1} ) D. litre^ sec- |
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99 | For a given reaction, pressure of catalyst reduces the energy of activation by 2 kcal at ( 27^{0} C . ) The rate of reaction will be increased by: A. 20 times B. 14 times c. 28 times D. 2 times |
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100 | A chemical reaction ( A+2 B rightarrow A B_{2} ) follows in two steps: ( A+B rightarrow A B(text { slow }) ) ( A B+B rightarrow A B_{2}(text { fast }) ) Then the order of the reaction is: ( A cdot 3 ) B. 2 ( c cdot 1 ) D. |
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101 | For the reaction, ( 2 N_{2} O_{5}(g) longrightarrow ) ( 4 N O_{2}(g)+O_{2}(g), ) if the concentration of ( N O_{2} ) increases by ( 5.2 times 10^{-3} M ) in 100 sec, then the rate of reaction is: A ( cdot 1.3 times 10^{-5} M s^{-1} ) В ( cdot 5 times 10^{-4} mathrm{M} s^{-1} ) c. ( 7.6 times 10^{-4} M s^{-1} ) D. ( 2 times 10^{-3} M s^{-1} ) E ( .2 .5 times 10^{-5} M s^{-1} ) |
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102 | A first order reaction is ( 50 % ) complete in 25 minutes. Calculate the time for ( 80 % ) completion of the reaction. |
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103 | For a chemical reaction ( boldsymbol{A} rightarrow ) products the rate of disappearance of ( boldsymbol{A} ) is given by: ( frac{-d C_{A}}{d t}=frac{K_{1} C_{A}}{1+K_{2} C_{A}} ) at low ( C_{A} ) the reaction is of the …….order with rate constant. (Assume ( K_{1}, K_{2} ) are lesser than ( 1) ) |
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104 | The time taken-for ( 90 % ) Of a first-order reaction to complete is approximately a. 1.1 times that of half life b. 2.2 times that of half life c. 3.3 times that of half life d. 4.4 times that of half life |
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105 | In a reaction, a substance undergoes decomposition which is catalyzed in the presence of finely divided nickel. If there are enough sites on the surface of catalysts so that 20 molecules of substance react per second, the rate of reaction for a ( 1.0 mathrm{M} ) solution is: A ( .3 .34 times 10^{-23} ) mol ( L^{-1} s^{-1} ) B . 3.14 ( times 10^{-23} ) mol ( L^{-1} s^{-1} ) c. ( 3.68 times 10^{-23} ) mol ( L^{-1} s^{-1} ) D. None of these |
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106 | For a reversible reaction, ( A stackrel{boldsymbol{K}_{1}}{dot{boldsymbol{K}}_{2}} boldsymbol{B}, ) Ist order in both the directions, the rate of reaction is given by: ( mathbf{A} cdot K_{1}[A] ) ( mathbf{B} cdot-K_{2}[B] ) ( mathbf{c} cdot K_{1}[A]+K_{2}[B] ) ( mathbf{D} cdot K_{1}[A]-K_{2}[B] ) |
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107 | Acid hydrolysis of ester is first order reaction and rate constant is given by ( boldsymbol{k}=frac{mathbf{2 . 3 0 3}}{boldsymbol{t}} log frac{boldsymbol{V}_{infty}-boldsymbol{V}_{mathbf{0}}}{boldsymbol{V}_{infty}-boldsymbol{V}_{boldsymbol{t}}} ) where, ( boldsymbol{V}_{0}, boldsymbol{V}_{boldsymbol{t}} ) and ( V_{infty} ) are the volume of standard NaOH required to neutralise acid present at a given time, if ester is ( 50 % ) neutralised then: ( mathbf{A} cdot V_{infty}=V_{t} ) В ( cdot V_{infty}=left(V_{t}-V_{0}right) ) C ( . V_{infty}=2 V_{t}-V_{0} ) D. ( V_{infty}=2 V_{t}+V_{0} ) |
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108 | Which among the following reaction is an example of a zero order reaction? B ( cdot 2 N H_{3(g)} stackrel{P t}{rightarrow} N_{2(g)}+3 H_{2} ) ( mathrm{c} cdot 2 mathrm{H}_{2} mathrm{O}_{2(l)} rightarrow 2 mathrm{H}_{2} mathrm{O}_{(l)}+O_{2(g)} ) D. ( H_{2(g)}+I_{2(g)} rightarrow 2 H I_{(g)} ) |
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109 | Question 11. Activation energy for the acid catalysed hydrolysis a sucrose is 6.22 kJ/mol, while the activation energy is only 2.15 kJ/mo when hydrolysis is catalysed by the enzyme invertase. Explain. 1. antaloreto reduce the magnitude al. |
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110 | The reaction ( N_{2} O_{5}left(text { in } C C l_{4}right) rightarrow ) ( 2 N O_{2}+1 / 2 O_{2}(g) ) is first order in ( N_{2} O_{5} ) with rate constant ( 6.2 times 10^{-4} ) What is the value of rate of reaction when ( left[N_{2} O_{5}right]=1.25 ) mole ( L^{-1} ) A ( cdot 7.75 times 10^{4} ) mol ( L^{-1} S^{-1} ) B. ( 6.35 times 10^{3} ) mol ( L^{-1} S^{-1} ) c. ( 5.15 times 10^{5} ) mol ( L^{-1} S^{-1} ) D. ( 3.85 times 10^{4} ) mol ( L^{-1} S^{-1} ) |
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111 | The temperature coefficient of a reaction is: A. ratio of rate constants at two temperature differing by ( 1^{o} C ) B. ratio of rate constants at temperature ( 35^{circ} mathrm{C} ) and ( 25^{circ} mathrm{C} ) C. ratio of rate constants at temperature ( 30^{circ} mathrm{C} ) and ( 25^{circ} mathrm{C} ) D. specific reaction rate by ( 25^{circ} ) |
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112 | In a first order reaction, the initial conc. of the reactant was ( M / 10 . ) After 8 minutes 20 seconds the conc. becomes ( M / 100 ) What is the rate constant? A. ( 5 times 10^{-3} ) second ( ^{-1} ) B. ( 2.303 times 10^{-5} ) second( ^{-1} ) c. ( 2.303 times 10^{-4} ) second( ^{-1} ) D. ( 4.606 times 10^{-3} ) second ( ^{-1} ) |
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113 | The incorrect statement is: A. all the collisions between reactant molecules do not lead to a chemical change B. a zero order reaction proceeds at a constant rate independent of concentration or time C. fast reactions have low activation energies D. in a first order reaction, the reaction ideally takes finite time to be completed |
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114 | A first order gaseous reactions has ( K=1.5 times 10^{-6} mathrm{sec}^{-1} ) at ( 200^{circ} mathrm{C} . ) If the reaction is allowed to run for 10 hour, what percentage of initial concentration would have changed into products. What is the half life period of reaction? |
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115 | Question 7. For a reaction, A+B – products, the rate law is rate = k [A][B]32. Can the reaction be an elementary reaction? Explain. |
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116 | The energy of activation and specific rate constant for a first order reaction at ( 25^{circ} mathrm{C} ) are ( 100 mathrm{kJ} / mathrm{mole} ) and ( 3.46 times ) ( 10^{-5} sec ^{-1} ) respectively. Determine the temperature at which half-life of the reaction is 2 hours: ( A cdot 306 k ) B. 310 k ( c cdot 234 k ) D. 280 k |
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117 | The high temperature ( (approx 1200 K) ) decomposition of ( boldsymbol{C} boldsymbol{H}_{3} boldsymbol{C O O H}(boldsymbol{g}) ) occurs as follows, as per simultaneous 1 stercactions. ( boldsymbol{C H}_{3} boldsymbol{C O O H} stackrel{boldsymbol{K}_{1}}{longrightarrow} boldsymbol{C} boldsymbol{H}_{4}+boldsymbol{C O}_{2} ) ( boldsymbol{C H}_{3} boldsymbol{C O O H} stackrel{boldsymbol{K}_{2}}{longrightarrow} boldsymbol{C H}_{2} boldsymbol{C O}+boldsymbol{H}_{2} boldsymbol{O} ) What would be the ( % ) of ( mathrm{CH}_{4} ) by mole in the product mixture (excluding ( left.boldsymbol{C H}_{3} boldsymbol{C O O H}right) ? ) A ( cdot frac{50 k_{1}}{left(k_{1}+k_{2}right)} ) В. ( frac{100 k_{1}}{left(k_{1}+k_{2}right)} ) c. ( frac{200 k_{1}}{left(k_{1}+k_{2}right)} ) D. It depends on time |
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118 | Acid hydrolysis of ester in first order reaction and rate constant is given by ( boldsymbol{k}=frac{mathbf{2 . 3 0 3}}{boldsymbol{t}} log frac{boldsymbol{V}_{infty}-boldsymbol{V}_{0}}{boldsymbol{V}_{infty}-boldsymbol{V}_{t}} ) where ( boldsymbol{V}_{0}, boldsymbol{V}_{t} ) and ( V_{infty} ) are the volume of standard NaOH required to neutralise acid present at a given time, if ester is ( 50 % ) neutralised then: A. ( V_{infty}=V_{t} ) B ( cdot V_{infty}=left(V_{t}-V_{0}right) ) ( mathbf{c} cdot V_{infty}=left(2 V_{t}-V_{0}right) ) D. ( V_{infty}=left(2 V_{t}+V_{0}right) ) |
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119 | For zero order reaction, the integrated rate equation is: A B. ( k t=[A]-[A]_{o} ) C ( cdot[A]=-k t+[A]_{0} ) ( mathbf{D} cdot[A]=k t-[A]_{o} ) |
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120 | Derive the relationship showing variation in rate constant with temperature |
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121 | The mechanism of the reaction ( mathbf{2} N boldsymbol{O}+boldsymbol{O}_{2} rightarrow mathbf{2} boldsymbol{N} boldsymbol{O}_{2} ) is: ( N O+N O underset{k_{-1}}{Gamma} N_{2} O_{2}(text { fast }) ; N_{2} O_{2}+ ) ( O_{2} stackrel{k_{2}}{longrightarrow} 2 N O_{2}(s l o w) ) The rate constant of the reaction is: ( mathbf{A} cdot k_{2} ) B. ( k_{2} k_{1}left(k_{-1}right) ) ( mathbf{c} . k_{2} k_{1} ) D ( quad k_{2}left(frac{k_{1}}{k_{-1}}right) ) |
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122 | In the following reaction ( ; x A rightarrow y B ) ( log _{10}left[-frac{boldsymbol{d}[boldsymbol{A}]}{boldsymbol{d} boldsymbol{t}}right]=log _{10}left[frac{boldsymbol{d}[boldsymbol{B}]}{boldsymbol{d} boldsymbol{t}}right]+mathbf{0 . 3 0 1 0} ) ‘A’ and ‘B’ respectively can be: A. n-Butane and Iso-butane B. ( C_{2} H_{4} ) and ( C_{4} H_{8} ) c. ( N_{2} O_{4} ) and ( N O_{2} ) D. ( C_{2} H_{2} ) and ( C_{6} H_{6} ) |
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123 | Derive the integrated rate equation for expressing the rate constant of a first order: ( boldsymbol{R} rightarrow boldsymbol{P} ) |
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124 | The rate of a chemical reaction generally increases rapidly even for small temperature increase because of a rapid increase in: A. Collision frequency B. Fraction of molecules with energies in excess of the activation energy c. Activation energy D. Average kinetic energy of molecules |
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125 | Assertion Active complex is an intermediate product. Reason Active complex is unstable with high vibrational energy. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion C. Assertion is correct but Reason is incorrect D. Assertion is incorrect but Reason is correct |
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126 | For a first order reaction ( boldsymbol{A} rightarrow mathbf{2} boldsymbol{B}+boldsymbol{C} ) It was found that at the end of 10 minutes from the start,the total optical rotation of the system was ( 60^{0} ) and when the reaction is complete.lt was ( 180^{0} . ) The ( mathrm{B} ) and ( mathrm{C} ) are only optically active and initially only A was taken. i) What is the rate constant of the above reaction (in hour)? ii) At what time (in minute) from the start, total optical rotation will be ( 90^{0} ) Take ( log 2=0.3, log 3=0.48, log 7=0.85, ) in 10 ( =2.3 ) |
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127 | For a first order reaction, ( boldsymbol{A} rightarrow ) Product the rate of reaction at ( [boldsymbol{A}]=mathbf{0 . 2} ) mol ( boldsymbol{L}^{-1} ) is ( 1.0 times 10^{-2} ) mol ( L^{-1} ) min ( ^{-1} . ) The half- life period for the reaction is: A ( cdot 832 ) s B. 440 s ( mathbf{c} cdot 416 mathrm{s} ) D. 14 s |
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128 | The rate of elementary reaction, ( boldsymbol{A} rightarrow boldsymbol{B} ) increases by 100 times when the concentration of ( A ) is increased ten folds. The order of the reaction with respect to A is: ( A ) B. 2 ( c cdot 10 ) D. 100 |
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129 | ( 99 % ) of a first – order reaction was completed in 32 min When will ( 99.9 % ) of the reaction complete? A. 50 Min B. 46Min c. 49 Min D. 48Min |
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130 | If half-life of a substance is 5 yrs, then the total amount of substance left after 15 years, when initial amount is 64 grams is: A. 16 grams B. 2 grams c. 32 grams D. 8 grams |
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131 | Which statements are correct in terms of chemical kinetic stuides? This question has multiple correct options A. The quenching of a reaction can be made by cooling the reaction mixture. B. The quenching of a reaction can be made by diluting the reaction mixture. C. The reaction is supposed to be completed if it is kept for long time or strongly heated. D. None of the above |
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132 | The unit of rate of reaction varies with order of reaction. A . True B. False |
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133 | An increase in the rate of a reaction for a rise in temperature is due to: This question has multiple correct options A. increase in collision frequency B. shortening of mean free path C. increase in the number of activated molecules D. none of the above |
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134 | Among the following which will decrease the rate of the reaction? i. Using highly concentrated reactants ii. Decreasing the temperature by ( 25 K ) iii. Stirring the reactants A. i only B. ii only c. i and iii only D. ii and iii only E. i, ii, and iii |
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135 | If ( v ) is rate corresponding to ( P_{C H_{3} C H O}=P_{1}, ) what is the order of reaction when ( boldsymbol{P}_{C H_{3} C H O}=4 P_{1} ? ) A . в. ( c cdot 1.5 ) ( D ldots ) |
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136 | Which of the following are pseudo unimolecular reactions? This question has multiple correct options ( mathbf{A} cdot C H_{3} C O O C_{2} H_{5}+H O H stackrel{H^{+}}{longrightarrow} C H_{3} C O O H+ ) ( C_{2} H_{5} O H ) B ( cdot C H_{3} C O O C_{2} H_{5}+H O H stackrel{O H^{-}}{longrightarrow} C H_{3} C O O H+ ) ( C_{2} H_{5} O H ) ( ^{mathbf{C}} cdot C_{12} H_{22} O_{11}+H O H frac{H^{+}}{rightarrow} begin{aligned} C_{6} H_{12} O_{6}_{+} C_{6} H_{12} O_{6} & \ & g l u c o s e quad text { fructose } end{aligned} ) D ( cdot S O_{2} C l_{2}(g) longrightarrow S O_{2}(g)+C l_{2}(g) ) |
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137 | For a chemical reaction ( A rightarrow ) Products the rate of reaction doubles when the concentration of ( A ) is increased by 4 times. The order of reaction is: ( A cdot 4 ) B. 0 ( c cdot 1 / 2 ) ( D ) |
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138 | For the reaction ( A+B rightarrow ) Products, it is found that the order of the reactions ( A ) and ( mathrm{B} ) are 1 and ( 2, ) respectively. When the concentration of ( A ) is halved and that of ( mathrm{B} ) is doubled, the rate increases by a factor of: |
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139 | The thermal decomposition of a compound is of first order. If ( 50 % ) of a sample of the compound is decomposed in 120 min how long will it take for ( 90 % ) of the compound to decompose? A. 412 min B. 399 min c. ( 450 mathrm{min} ) D. 499 min |
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140 | Consider a certain reaction ( boldsymbol{A} rightarrow ) Products with, ( k=2.0 times 10^{-2} s^{-1} ) Calculate the concentration of ( mathbf{A} ) remaining after 100 s, if the initial concentration of ( A ) is ( 1.0 m o l L^{-1} ) |
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141 | A certain radioisotope ( _{Z}^{A} X ) (Half life ( = ) ( 10 text { days }) ) decays to ( _{Z-2}^{A-4} Y . ) If ( 1 g ) atom of ( A X ) is kept in sealed vessel, how much ( Z^{text {}} ) helium will accumulated in 20 days? |
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142 | Assertion Every collision of reactant molecule is not successful. Reason Every collision of reactant molecule with proper orientation is successful one. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion C. Assertion is correct but Reason is incorrect D. Assertion is incorrect but Reason is correct |
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143 | constant determined from Arrhenius equation are Q. 61 Assertion (A) Rate constant determined from Arre fairly accurate for simple as well as complex molecules Reason (R) Reactant molecules undergo chemical change their orientation during collision. |
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144 | The rate of reaction is doubled for every ( 10^{circ} mathrm{C} ) rise in temperature. The increase in rate as result of increase in temperature from ( 10^{circ} mathrm{C} ) to ( 100^{circ} mathrm{C} ) is: A . 112 B. 512 ( c cdot 400 ) D. 256 |
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145 | A graph of volume of hydrogen released vs time for the reaction between zinc and dil. ( H C l ) is given in figure. On the basis of this mark the correct option. ‘ Average rate upto 40 seconds is ( frac{V_{3}-V_{2}}{40} ) B. Average rate upto 40 seconds is ( frac{V_{3}-V_{2}}{40-30} ) c. average rate upto 40 seconds is ( frac{V_{3}}{40} ) ‘Average rate upto 40 seconds is ( frac{V_{3}-V_{1}}{40-20} ) |
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146 | .23 In any unimolecular reaction ……… (a) only one reacting species is involved in the rate determining step (b) the order and the molecularity of slowest step are equal to one (c) the molecularity of the reaction is one and order is zero (d) both molecularity and order of the reaction are one |
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147 | Which of the following are examples of pseudo unimolecular reactions? ( mathbf{A} cdot C H_{3} C O_{2} C_{2} H_{5}+H_{2} O rightarrow C H_{3} C O_{2} H+C_{2} H_{5} O H ) ( mathbf{B} cdot C_{12} H_{22} O_{11}+H_{2} O rightarrow C_{6} H_{12} O_{6}+C_{6} H_{12} O_{6} ) ( mathbf{c} cdot C H_{3} C O C l+H_{2} O rightarrow C H_{3} C O_{2} H+H C l ) D. All of the above |
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148 | Specific reaction rate is rate of reaction at unit concentration of reactants. A. True B. False |
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149 | The rate of the reaction ( boldsymbol{A}+boldsymbol{B}_{2} rightarrow ) ( A B+B ; ) is directly proportional to the concentration of ( A ) and independent of concentration of ( B_{2} ), hence, rate law is: ( mathbf{A} cdot k[A]left[B_{2}right] ) ( mathbf{B} cdot k[A]^{2}left[B_{2}right] ) c. ( k[A] ) D. ( kleft[B_{2}right] ) |
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150 | Consider the chemical reaction, ( N_{2}(g)+3 H_{2}(g) longrightarrow 2 N H_{3}(g) ) The rate of reaction can be expressed in terms of time derivative of concentration of ( boldsymbol{N}_{2}(boldsymbol{g}), boldsymbol{H}_{2}(boldsymbol{g}) ) or ( N H_{3}(g) . ) Identify the correct relationship amongst the rate expressions. A ( cdot operatorname{Rate}=-frac{dleft[N_{2}right]}{d t}=-frac{1}{3} frac{dleft[H_{2}right]}{d t}=+frac{1}{2} frac{dleft[N H_{3}right]}{d t} ) B. Rate ( =-frac{dleft[N_{2}right]}{d t}=-3 frac{dleft[H_{2}right]}{d t}=+2 frac{dleft[N H_{3}right]}{d t} ) ( ^{mathbf{c}} cdot_{mathrm{Rate}}=frac{dleft[N_{2}right]}{d t}=frac{1}{3} frac{dleft[H_{2}right]}{d t}=frac{1}{2} frac{dleft[N H_{3}right]}{d t} ) D. ( operatorname{Rate}=-frac{dleft[N_{2}right]}{d t}=-frac{dleft[H_{2}right]}{d t}=frac{dleft[N H_{3}right]}{d t} ) |
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151 | For the reaction given below, ( mathbf{2} mathbf{O}_{mathbf{3}}(mathbf{g}) rightarrow mathbf{3} mathbf{O}_{mathbf{2}}(mathbf{g}) ) ( operatorname{Step} mid: mathbf{O}_{3}(mathbf{g}) rightarrow mathbf{O}_{2}(mathbf{g})+mathbf{O}(mathbf{g}) ) Step ( 2: mathrm{O}_{3}(mathrm{g})+mathrm{O} rightarrow^{text {slow }} 2 mathrm{O}_{2}(mathrm{g}) ) Statement I: The molecularity of the first step is 1 and of the second step is 2 Statement-II: ( O(g) ) is an intermediate and rate of reaction is ( mathbf{K}left[mathbf{O}_{3}right]^{2}left[mathbf{O}_{2}right]^{-1} ) and order of reaction is 1 A. Both statements are true Statement – – ll is correct explanation of Statement- – B. Both statements are true but Statement- -II is not correct explanation of Statement- – c. Statement – – lis true but Statement – II is false D. Statement-lis false but Statement- 11 is true |
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152 | Question 6. Time required to decompose SO,C1, to half of its initial amount is 60 min. If the decomposition is a first order reaction, calculate the rate constant of the reaction. The time in which a substance is reduced to half of its original quantity is e called its half-life, tywe have t o calculate k from the formula, k=0.693/ty2 (for Ist order reaction) |
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153 | For a chemical reaction, ( boldsymbol{A} rightarrow boldsymbol{B} ), it is observed that the rate of reaction doubles when the concentration of ( A ) is increased four times. The order of reactions in ( A ) is : A. Two B. One c. Half D. zero |
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154 | For a gaseous reaction ( boldsymbol{A} rightarrow boldsymbol{B}+mathbf{2} boldsymbol{C} ) at ( 250^{circ} mathrm{C}, ) following data were observed. The partial pressure of the gases at 100th min will be (in 100x mm) Time 20 ( quad 40 ) [ (min ) ] Total pressure ( (mathrm{mm} mathrm{Hg}) ) 587.6 |
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155 | For the reaction ( N_{2}(g)+3 H_{2}(g) rightarrow ) ( 2 N H_{3}(g), ) under certain conditions of temperature and partial pressure of the reactants, the rate of formation of ( boldsymbol{N} boldsymbol{H}_{3} ) is ( 1.0 times 10^{-4} ) mollit ( ^{-1} h^{-1} ). The rate of conversion of ( boldsymbol{H}_{2} ) under the same conditions is: A ( cdot 6.7 times 10^{-4} ) mollit ( ^{-1} h^{-1} ) B. ( 3.3 times 10^{-3} ) mollit ( ^{-1} h^{-1} ) c. ( 1.5 times 10^{-4} ) mollit ( ^{-1} h^{-1} ) D. ( 0.5 times 10^{-4} ) mollit ( ^{-1} h^{-1} ) |
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156 | According to the collision theory, most molecular collisions do not lead to a reaction. Which of the following is(are) necessary for collisions to successfully lead to the reaction? This question has multiple correct options A. The total kinetic energy of the collision must be greater than some minimum value B. A catalyst must be present at the collision. c. The colliding particles must be properly oriented in space when they collide. D. None of the above |
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157 | If ( c ) is the concentration of ( n ) moles of a gas at pressure ( P ) and temperature ( T ) then for the ideal gas reaction. the rate of reaction can be given by : A ( cdot-frac{d[A]}{d t} ) B. ( -frac{1}{R T} frac{d P}{d t} ) c. ( -frac{1}{nu} frac{d n}{d t} ) D. either of these |
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158 | of a reaction cannot be determined experimentally A. Order B. Rate c. Rate constant D. Molecularity |
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159 | A substance reacts according to order kinetic and rate constant for the reaction is ( 1 times 10^{-2} )sec( ^{-1} ). If the initial concentration is ( 1 mathrm{M} ) Rate of the reaction after 1 minute is: |
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160 | For which of the following reactions ( k_{310} / k_{300} ) would be maximum? A ( cdot A+B rightarrow C ; E_{a}=50 k J ) в. ( X+Y rightarrow Z ; E_{a}=40 k J ) c. ( P+Q rightarrow R ; E_{a}=60 k J ) D. ( E+F rightarrow G ; E_{a}=100 k J ) |
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161 | For the first order reaction, ( boldsymbol{A}(boldsymbol{g}) rightarrow ) ( 2 B(g)+C(g), ) the initial pressure is ( boldsymbol{P}_{boldsymbol{A}}=mathbf{9 0} ) mm Hg. Then pressure after 10 minutes is found to be 180 mm Hg. The half-life period of the reaction is: A ( cdot 1.15 times 10^{-3} mathrm{sec}^{-1} ) в. 600 sec c. ( 3.45 times 10^{-3} s e c^{-1} ) D. 200 sec |
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162 | Which equation represents the time to complete ( 90 % ) of first order reaction? A ( cdot frac{k}{2.303} log frac{4}{3} ) в. ( frac{2.303}{k} log _{frac{3}{4}} ) c. ( frac{2.303}{k} ) D. ( frac{2.303}{k} log 3 ) |
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163 | Match the column | 12 |
164 | For a first order reaction, the ratio of the time taken for ( 7 / 8^{t h} ) of the reaction to complete to that of half of the reaction to complete is : A . 3: 1 B. 1: 3 c. 2: 3 D. 3: 2 |
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165 | The mechanism of the reaction ( mathbf{2} N boldsymbol{O}+boldsymbol{O}_{2} rightarrow mathbf{2} boldsymbol{N} boldsymbol{O}_{2} ) is: ( N O+N O underset{k_{-1}}{Gamma} N_{2} O_{2}(text { fast }) ; N_{2} O_{2}+ ) ( O_{2} stackrel{k_{2}}{longrightarrow} 2 N O_{2}(s l o w) ) The rate constant of the reaction is : ( A cdot(A) k_{2} ) B . (В) ( k_{2} k_{1}left(k_{-1}right) ) c. (с) ( k_{2} k ) D. (D) ( k_{2}left(frac{k_{1}}{k_{-1}}right) ) |
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166 | Units of the rate constant of first and zero order reactions in terms of molarity M unit are respectively: A ( cdot sec ^{-1}, ) M sec ( ^{-1} ) B . ( sec ^{-1}, ) М c. ( M s e c^{-1}, s e c^{-1} ) D. ( M, s e c^{-1} ) |
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167 | is the unit for the rate of a chemical reaction. A. Mole ( I^{-1} ) s B. Mole ( left.right|^{-1} mathrm{s}^{-1} ) c. Mole I s D. Mole ( 1^{-1} ) |
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168 | In the first order reaction ( 75 % ) of the reactant disappeared in 1.388 hrs Calculate the rate constant of the reaction: A ( cdot 1 s^{-1} ) – ( ^{-1} ) B. ( 2.8 times 10^{-4} s^{-1} ) c. ( 17.2 times 10^{-3} s^{-1} ) D. ( 1.8 times 10^{-3} s^{-1} ) |
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169 | For the hydrolysis of methyl acetate in aqueous solution, the above tabulated results were obtained: (i) Show that it follow pseudo first order reaction as the concentration of water remains constant. (ii) Calculate the average rate of reaction between the time interval 30 to 60 seconds. (Given log ( 2=0.3010, ) log ( 4=0.6021 ) ) begin{tabular}{|c|c|c|c|} hline ( mathrm{t} / mathrm{s} ) & 0 & 30 & 60 \ hline ( mathrm{c} mathrm{CH}_{3} mathrm{COOH}_{3} ) & ( / mathrm{moll}^{-1} ) & 0.60 & 0.30 & 0.15 \ hline end{tabular} |
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170 | During nuclear explosion, one of the products is ( ^{90} ) Sr with half life of 28.1 yr. If ( 1 mu g ) of ( ^{90} S r ) was absorbed in the bones of a newly born baby instead of calcium, how much of it will remain after 10 year and 60 year if it is not lost metabolically. |
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171 | ( 2 C+O_{2}=2 C O . ) The rate of disappearance of ( boldsymbol{C} ) is ( 2 times ) ( 10^{-3} ) mol ( L^{-1} ) sec ( ^{-1} ). What is the instantaneous rate of the reaction? A. ( 2 times 10^{-3} ) В. ( 1 times 10^{-3} ) c. ( 4 times 10^{-3} ) D. None of these |
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172 | A graph of volume of hydrogen released vs time for the reaction between zinc and dil. ( H C l ) is given. Find the instantaneous rate of reaction at 40 sec is : A. ( frac{V_{3}-V_{2}}{40} ) B. ( frac{V_{2}-V_{1}}{20} ) c. ( frac{V_{3}-V_{1}}{40} ) D. cannot be determined |
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173 | Reaction, ( 5 C longrightarrow 3 A+2 B . ) The rate of formation of ( boldsymbol{A} ) is ( mathbf{0 . 0 2 7 m o l} boldsymbol{L}^{-1} boldsymbol{s e c}^{-1} ) What will be the rate of disappearance of ( C ? ) A. ( 0.090 mathrm{molL}^{-1} mathrm{sec}^{-1} ) B. ( 0.027 mathrm{molL}^{-1} mathrm{sec}^{-1} ) c. ( 0.063 m o l L^{-1} s e c^{-1} ) D. ( 0.045 mathrm{molL}^{-1} mathrm{sec}^{-1} ) |
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174 | The rate constant of a first order reaction is ( 1.54 times 10^{-3} ) sec ( ^{-1} ). Calculate its half life period. |
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175 | For a reaction ( boldsymbol{X} rightarrow boldsymbol{Y} ) ), heat of reaction is ( +83.68 k J, ) energy of reactant ( X ) is ( 167.36 k J ) and energy of activation is ( 209.20 k J . ) Calculate (i) threshold energy (ii) energy of product ( Y ) and (iii) energy activation of the reverse reaction ( (boldsymbol{Y} rightarrow boldsymbol{X}) ) |
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176 | The reaction of nitrogen and oxygen to form nitric oxide is favored by high temperature. A. True B. False |
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177 | At ( 373 K, ) gaseous reaction ( A rightarrow ) ( 2 B+C ) is found to be first order. Starting with pure ( A ), the total pressure at the end of 10 min. was 176 mm and after a long time when ( A ) was completely dissociated, it was 270 mm. The pressure of ( A ) at the end of 10 minutes was: A . ( 94 mathrm{mm} ) B. ( 47 mathrm{mm} ) c. 43 mm D. ( 90 mathrm{mm} ) |
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178 | The rate of a reaction doubles when its temperature changes from ( 300 K ) to ( 310 K . ) Activation energy of such a reaction will be : ( (boldsymbol{R}= ) ( left.8.314 J K^{-1} m o 1^{-1} text {and } log 2=0.301right) ) A ( .48 .6 mathrm{kJmol}^{-1} ) B. 58.5 kJmol( ^{-1} ) ( mathbf{c} cdot 60.5 k J m o l^{-1} ) D. ( 53.6 mathrm{kJmol}^{-1} ) |
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179 | Explain the concept of reaction with no order. |
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180 | When one molar concentrations of reactants are taken, rate of reaction is equal to: A. molar concentration B. reaction rate c. rate constant D. equilibrium rate |
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181 | The molecularity of a reaction will be: A . fractional B. zero c. positive whole number D. negative |
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182 | The rate law of the reaction ( boldsymbol{C}_{2} boldsymbol{H}_{4} boldsymbol{B} boldsymbol{r}_{2}+boldsymbol{3} boldsymbol{l}^{-} rightarrow boldsymbol{C}_{2} boldsymbol{H}_{4}+boldsymbol{2} boldsymbol{B} boldsymbol{r}^{-}+ ) ( boldsymbol{I}_{3}^{-} ) is rate ( =boldsymbol{k}left[boldsymbol{C}_{2} boldsymbol{H}_{4} boldsymbol{B} boldsymbol{r}_{2}right]left[boldsymbol{I}^{-}right] . ) The rate of reaction is found to be ( 1.1 times 10^{-4} M / s ) when the concentrations of ( C_{2} H_{4} B r_{2} ) and ( I^{-} ) are ( 0.12 mathrm{M} ) and ( 0.18 mathrm{M} ) respectively. Calculate the rate constant of the reaction. ( mathbf{A} cdot 4.27 times 10^{-3} M^{-1} s^{-1} ) B . ( 1.65 times 10^{-3} M^{-1} s^{-1} ) C ( .5 .1 times 10^{-3} M^{-1} s^{-1} ) D. None of these |
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183 | The rate of change in concentration of ( C ) in the reaction ( 2 A+B rightarrow 2 C+3 D ) was reported as 1.0 mol litre ( ^{-1} ) sec ( ^{-1} ) Calculate the reaction rate. A. 0.05 mol litre ( ^{-1} ) sec ( ^{-1} ) B. 0.01 mol litre ( ^{-1} ) sec ( ^{-1} ) c. 0.5 mol litre ( ^{-1} ) sec ( ^{-1} ) D. 5 mol litre ( ^{-1} ) sec ( ^{-1} ) |
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184 | In a first order reaction, the concentration of product ‘x’ at time ‘t’ is given by the expression: (where,a = initial concentration, ( mathbf{k}= ) rate constant, ( n=text { order }) ) A ( cdot x=aleft(1-e^{-k t}right) ) в. ( x=frac{1}{(a-x)} ) c. ( _{x}=frac{1}{2^{n-1}} ) D. ( x=frac{a}{(a-x)} ) |
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185 | For a zero order reaction at ( 200 K ) reaction complete in 5 minutes while at ( 300 K, ) same reaction, completes in 2.5 minutes. What will be the activation energy in calorie? ( (boldsymbol{R}= ) ( mathbf{2} text { Cal } /(text { mol. } boldsymbol{K}) ; boldsymbol{l n} mathbf{2}=mathbf{0 . 7}) ) |
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186 | In elementary reaction steps, which of the following is most likely to have the highest rate? A. A reaction where three reactants combine B. A reaction with only one reactant C. A reaction where two reactants combine D. A reaction where two reactants undergo double displacement. |
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187 | The amount left after completion of average life period in a first order reaction is : A ( cdot frac{a(e-1)}{e+1} ) B. ( frac{a}{e-1} ) c. ( frac{a(e-1)}{e} ) D. |
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188 | For gaseous reaction, the unit of the rate of reaction is: ( A cdot L a t m sec ^{-1} ) B. atm mol sec ( ^{-1} ) ( mathbf{c} cdot operatorname{atm} sec ^{-1} ) D. mol sec |
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189 | ( N_{2} O_{2}(g) rightarrow 2 N O ) is a first-order reaction interms of the concentration of ( N_{2} O_{2}(g) . ) Which of the following is valid, ( left[N_{2} O_{2}right] ) being constant? A ( cdot[N O]=left[N_{2} O_{2}right]_{0} e^{-k t} ) B . ( [N O]=left[N_{2} O_{2}right]_{0}left(1-e^{k t}right) ) C ( cdot[N O]=left[N_{2} O_{2}right]_{0}left(e^{-k t}-1right) ) D ( cdot[N O]=left[N_{2} O_{2}right]_{0}left(1-e^{-k t}right) ) |
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190 | The rate of a reaction expressed in terms of change in concentration of products at two different times, that is the average rate in terms of product, can be written as ? This question has multiple correct options A ( cdot frac{x_{2}-x_{1}}{t_{2}-t_{1}} ) B. ( +Delta x / Delta t ) c. ( -frac{x_{2}-x_{1}}{t_{2}-t_{1}} ) D. ( -Delta x / Delta t ) |
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191 | A chemist prepares ( 1.00 g ) of pure ( _{6}^{11} C . ) This isotope has half life of 21 minutes, decaying by the equation: [ _{6}^{11} C rightarrow_{5}^{11} B+_{1}^{0} e ] (a) What is the rate of disintegration per second (dps) at start? (b) What are the activity and specific activity of ( _{6}^{11} mathrm{C} ) at start? (c) How much of this isotope ( _{6}^{11} C ) is left after 24 hours of its preparation? |
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192 | The graph above shows the variation in concentration of reactants and products as ( H_{2} ) and ( I_{2} ) react to form ( mathrm{H} ) at a temperature. Equilibrium is reached when the concentration of HI is ( A cdot A ) B. B ( c . c ) D. ( E ) |
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193 | Reaction rate increases with A. concentration B. pressure c. both a and ( b ) D. none of above |
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194 | Write four differences between rate of reaction and constant. |
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195 | The following data were obtained during the first order thermal decomposition of ( S O_{2} C l_{2} ) at a constant volume. [ boldsymbol{S} boldsymbol{O}_{2} boldsymbol{C l}_{2}(boldsymbol{g}) rightarrow boldsymbol{S} boldsymbol{O}_{2}(boldsymbol{g})+boldsymbol{C l}_{2}(boldsymbol{g}) ] Total pressure/ atm Experiment A Time ( / s^{-1} ) 100 Calculate the rate of the reaction when total pressure is 0.65 at ( m ) |
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196 | The time for half-life period of a certain reacting ( boldsymbol{A} rightarrow ) product is an hour. How much time does it take for its concentration to come from 0.50 to 0.25 ( operatorname{mol} L^{-1} ) if it is a zero order reaction? A . ( 0.25 h ) B. 1h ( c cdot 4 h ) D. 0.5h |
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197 | suppose 0 [ text { 135 } quad 342 ] [ t(min ) ] and [Cone] 1.91 mol ( L^{-1} quad ) 2.08 1.67 Find out the order of reaction and calculate its rate constants |
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198 | Slowest reaction among the following under identical conditions is: A ( cdot N a O H+H C l rightarrow N a C l+H_{2} O ) B. ( H^{+}+O H^{-} rightarrow H_{2} O ) ( mathrm{c} cdot 2 mathrm{N} mathrm{O}+mathrm{O}_{2} rightarrow 2 mathrm{N} mathrm{O}_{2} ) D. ( C H_{4}+2 O_{2} rightarrow C O_{2}+2 H_{2} O ) |
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199 | (A) Half-life of a first order reaction is independent of the initial concentration of reactant (R) ( t_{1 / 2} ) (first order) ( =tau / 1.44 ) where, ( boldsymbol{tau} ) =average life. A. Both (R) and (A) are true and reason is the correct explanation of assertion B. Both (R) and (A) are true but reason is not correct explanation of assertion c. Assertion (A) is true but reason (R) is false D. Assertion (A) and reason (R) both are false E. Assertion (A) is false but reason (R) is true |
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200 | During the kinetic study of the reaction, ( mathbf{2} boldsymbol{A}+boldsymbol{B} rightarrow boldsymbol{C}+boldsymbol{D} ) following results were obtained. ( begin{array}{lll} & {[mathrm{A}]} & {[mathrm{B}]} \ & text { Run } & text { in } & text { in } \ & text { M } & text { M }end{array} ) Iniitial rate of formation of D in ( boldsymbol{m} boldsymbol{s}^{-1} ) 0.1 ( 0 . ) ( 6.0 times 10^{-3} ) ( begin{array}{ll}0.2 & 7.2 times 10^{-2}end{array} ) 0.3 ( 2.88 times 10^{-1} ) 0.3 0.4 0.4 ( begin{array}{ll}0.1 & 2.40 times 10^{-2}end{array} ) On the basis of above data which one is correct? A ( cdot r=k[A]^{2}[B] ) B. ( r=k ) (A)[B] C ( cdot r=k[A]^{2}[B]^{2} ) D . ( r=k[A][B]^{2} ) |
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201 | C if the Question 2. Write the rate equation for the reaction, 2A + B order of the reaction is zero. |
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202 | Question 3. For a reaction, A+B – product; the rate law is given by, r=k[A]1/2 [B]. What is the order of the reaction? Order =Sum of powers of the concentration of reactants. |
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203 | A graph of concentration versus time data for a second-order reaction gives a straight line in which of the following plots of the data? A ( cdot[A]_{t}=-k t+[A]_{0} ) B ( cdot ln [A]_{t}=-k t+ln [A]_{0} ) c. ( frac{1}{left[A_{t}right]}=k t+frac{1}{left[A_{0}right]} ) D. All of the above E. None of the above |
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204 | A following mechanism has been proposed for a reaction: ( mathbf{2} boldsymbol{A}+boldsymbol{B} rightarrow boldsymbol{D}+boldsymbol{E} ) ( boldsymbol{A}+boldsymbol{B} rightarrow boldsymbol{C}+boldsymbol{D} quad(text { slow }) ) ( boldsymbol{A}+boldsymbol{C} rightarrow boldsymbol{E} quad(text { fast }) ) The rate law expression for the reaction is: ( mathbf{A} cdot mathbf{r}=k[A]^{2}[B] ) B. ( r=k[ ) A][B] ( mathbf{C} cdot r=k[A]^{2} ) D. ( r=k[A][C] ) |
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205 | With respect to the figure which of the following statement is correct? ( A cdot E_{A} ) for forward reaction is ( E_{A}-E_{B} ) B. ( E_{A} ) for forward reaction is ( E_{C}-E_{A} ) ( mathrm{c} cdot E_{A} ) for reverse reaction is greater than ( E_{A} ) for forward reaction D. ( E_{A} ) for forward reaction is greater than ( E_{A} ) for backward reaction |
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206 | For the reaction ( 2 N H_{3} rightarrow N_{2}+3 H_{2} ) ( mathbf{f}-frac{boldsymbol{d}left[boldsymbol{N} boldsymbol{H}_{3}right]}{boldsymbol{d} t}=boldsymbol{k}_{1}left[boldsymbol{N} boldsymbol{H}_{3}right], frac{boldsymbol{d}left[boldsymbol{N}_{2}right]}{boldsymbol{d} t}= ) ( boldsymbol{k}_{2}left[boldsymbol{N} boldsymbol{H}_{3}right], frac{boldsymbol{d}left[boldsymbol{H}_{2}right]}{boldsymbol{d} t}=boldsymbol{k}_{3}left[boldsymbol{N} boldsymbol{H}_{3}right] ) then the relation between ( k_{1}, k_{2} ) and ( k_{3} ) is? ( mathbf{A} cdot k_{1}=k_{2}=k_{3} ) B. ( k_{1}=3 k_{2}=2 k_{3} ) c. ( 1.5 k_{1}=3 k_{2}=k_{3} ) D ( cdot 2 k_{1}=k_{2}=3 k_{3} ) |
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207 | Which among the following is/ are correct for a first order reaction? This question has multiple correct options A. The degree of dissociation is equal to ( left(1-e^{-k t}right) ) B. A plot of reciprocal concentration of the reactant vs time gives a straight line. C. The time taken for the completion of 75% reaction is thrice the ( t_{1 / 2} ) of reaction. D. The pre-exponential factor in the Arrhenius equation has the dimension of time, ( T^{-1} ) |
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208 | The hydrolysis of ethyl acetate is a reaction of: ( boldsymbol{C H}_{3} boldsymbol{C O O C}_{2} boldsymbol{H}_{5}+boldsymbol{H}_{2} boldsymbol{O} stackrel{boldsymbol{H}^{+}}{longrightarrow} ) ( boldsymbol{C H}_{3} boldsymbol{C O O H}+boldsymbol{C}_{2} boldsymbol{H}_{5} boldsymbol{O H} ) A. zero order B. first order c. second order D. third order |
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209 | For a chemical reaction to occur, all of the following must happen except. A. A large enough number of collisions must occur B. Chemical bonds in the reactants must break C. Reactant particles must collide which enough energy for change to occur D. Reactant particles must collide with correct orientation |
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210 | Consider the reaction: [ begin{array}{l} boldsymbol{C l}_{2}(boldsymbol{a} boldsymbol{q})+boldsymbol{H}_{2} boldsymbol{S}(boldsymbol{a} boldsymbol{q}) rightarrow boldsymbol{S}(boldsymbol{s})+ \ boldsymbol{2} boldsymbol{H}^{+}(boldsymbol{a} boldsymbol{q})+boldsymbol{2} boldsymbol{C l}^{-}(boldsymbol{a} boldsymbol{q}) end{array} ] The rate equation for this reaction is rate ( =boldsymbol{k}left[boldsymbol{C l}_{2}right]left[boldsymbol{H}_{2} boldsymbol{S}right] ) Which of these mechanisms is /are consistant with this rate equation? ( (mathbf{A}) boldsymbol{C l}_{2}+boldsymbol{H}_{2} boldsymbol{S} rightarrow boldsymbol{H}^{+}+boldsymbol{C l}^{-}+boldsymbol{C l}^{+}+ ) ( boldsymbol{H} boldsymbol{S}^{-} quad(text { slow }) ) [ boldsymbol{C l}^{+}+boldsymbol{H} boldsymbol{S}^{-} rightarrow boldsymbol{H}^{+}+boldsymbol{C l}^{-}+boldsymbol{S} ] (fast) (B) ( boldsymbol{H}_{2} boldsymbol{S} rightleftharpoons boldsymbol{H}^{+}+boldsymbol{H} boldsymbol{S}^{-} ) (fast equilibrium) [ boldsymbol{C l}_{2}+boldsymbol{H} boldsymbol{S}^{-} rightarrow boldsymbol{2} boldsymbol{C l}^{-}+boldsymbol{H}^{+}+boldsymbol{S} ] (slow) A. B only B. Both A and B C. Neither A nor B D. A only |
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211 | How an increase in concentration is related to number of collisions? A. Directly B. Inversely c. Has no effect D. None |
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212 | Decomposition of ( boldsymbol{H}_{2} boldsymbol{O} ) is a first order reaction. A 16 volume solution of ( boldsymbol{H}_{2} boldsymbol{O}_{2} ) of half-life period 30 minutes is present at the start. When will the solution become one volume? A. After 120 minutes B. After 90 minutes c. After 60 minutes D. After 140 minutes |
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213 | For an elementary reaction, ( boldsymbol{X}(boldsymbol{g}) rightarrow ) ( boldsymbol{Y}(boldsymbol{g})+boldsymbol{Z}(boldsymbol{g}): ) the half life period is 10 min. In what period of time would the concentration of ( X ) be reduced to ( 10 % ) of original concentration? A . 20 min B. 33 min ( c .15 ) min D. 25 min |
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214 | The energy change accompanying the equilibrium reaction ( boldsymbol{A} rightleftharpoons boldsymbol{B} ) is ( -33.0 k J m o l^{-1} ) Assuming that pre-exponential factor is same for forward and backward reaction. The equilibrium constant K for the reaction at ( 300 mathrm{K} ) ( mathbf{A} cdot 5.55 times 10^{5} ) B . ( 5.67 times 10^{3} ) ( mathbf{c} cdot 5.55 times 10^{6} ) ( mathbf{D} cdot 5.67 times 10^{2} ) |
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215 | Q.51 Why molecularity is applicable only for elementary reactions and order is applicable for elementary as well as complex reactions? Aanmelawati |
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216 | The metabolism of an antibiotic, ( ^{prime} boldsymbol{A}^{prime} ) is first-order rate process. The rate constant ‘K’ for this process depends on temperature and body weight but for a 70 kg man at ( 37^{circ} mathrm{C} ) its value is ( boldsymbol{K}= ) ( 3.0 times 10^{-5} mathrm{sec}^{-1} . ) How long after taking the first pill containing ( 400 mathrm{mg} ) of antibiotic must this man take the second pill to keep the concentration at 200 mg per 100 kg body weight? (Assume instantaneous uniform distribution of the antibiotic throughout the body? A ( cdot 0.7 times 10^{4} sec ) B. ( 1.5 times 10^{4} ) sec c. ( 1.4 times 10^{4} ) sec D. ( 3.6 times 10^{4} ) sec |
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217 | When a piece of zinc metal is added to a solution of hydrochloric acid, a reaction occurs. The products are aqueous zinc chloride and hydrogen gas. Which of the following conditions would result in the fastest rate of reaction with ( 1.00 g ) of zinc? ( mathbf{A} cdot 0.010 M H C l ) at ( 10^{circ} C ) B . ( 0.010 M ) HCl at ( 80^{circ} mathrm{C} ) c. ( 0.10 M ) HCl at ( 10^{circ} ) C D. ( 0.10 M H C l ) at ( 80^{circ} C ) |
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218 | 0.58 Assertion (A) Order and molecularity are same. Reason (R) Order is determined experimentally and molecularity is the sum of the stoichiometric coefficient of rate determining elementary step. |
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219 | ( 92 U^{238} ) by successive radioactive decays changes to ( _{82} P b^{206} ). A sample of uranium ore was analysed and found to contain ( 1.0 g U^{238} ) and ( 0.1 g P b^{206} ) has accumulated due to decay of uranium, find out the age of ore. ( t_{1 / 2} ) for ( U^{238}= ) ( 4.5 times 10^{9} y e a r ) | 12 |
220 | The rate of reaction: This question has multiple correct options A. decreases with time B. decreases with decrease in conc. of reactant c. decreases with increase in time and decrease in conc. of reactant D. none of the above |
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221 | Trimolecular reactions are uncommon because: A. the probability of three molecules colliding at an instant is very low B. the probability of three molecules colliding at an instant is high C. the probability of three molecules colliding at an instant is zero D. the probability of many molecules colliding at an instant is high |
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222 | Consider the Arrhenius equation given below and mark the correct option ( : k= ) ( boldsymbol{A} boldsymbol{e}^{-boldsymbol{E}_{a} / boldsymbol{R} boldsymbol{T}} ) A. Rate constant increases exponentially with increasing activation energy and decreasing temperature B. Rate constant decreases exponentially with increasing activation energy and decreasing temperature C. Rate constant increases exponentially with decreasing activation energy and decreasing temperature D. Rate constant increases exponentially with decreasing activation energy and increasing temperature |
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223 | . 46 What is the probability of reaction with molecularity higher than three very rare? all thoro must |
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224 | In a first order reaction, the concentration of the reactant, decreases from ( 0.8 mathrm{M} ) to ( 0.4 mathrm{Min} 15 ) minutes. The time taken for the concentration to change from ( 0.1 mathrm{M} ) to ( 0.025 mathrm{M} ) is: A. 30 min B. 15 min ( c .7 .5 mathrm{min} ) D. 60 min |
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225 | ( boldsymbol{C l}_{2} Leftrightarrow mathbf{2} boldsymbol{C l} ) ( boldsymbol{C H}_{4}+boldsymbol{C l} rightarrow boldsymbol{C H}_{3}+boldsymbol{H} boldsymbol{C l}(boldsymbol{s l o w}) ) ( boldsymbol{C H}_{3}+boldsymbol{C l}_{2} rightarrow boldsymbol{C H}_{2} boldsymbol{C l}+boldsymbol{C l} ) ( boldsymbol{C H}_{3} boldsymbol{C l}+boldsymbol{C l} rightarrow boldsymbol{C H}_{2} boldsymbol{C l}_{2}+boldsymbol{H} ) ( boldsymbol{H}+boldsymbol{C l} rightarrow boldsymbol{H} boldsymbol{C l} ) The above mechanism shows the overall reaction between chlorine gas and methane gas to form dichloromethane gas and hydrogen monochloride gas. The reaction is carried out in the gas state with no ions being formed during the reaction. Which of the following statements is not supported by the mechanism? |
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226 | For a reaction, calculate value of ratio, ( frac{[x]_{t}}{[y]+[z]} ) at any given instant ( t ) | 12 |
227 | Consider the reaction: ( mathbf{C l}_{2}(mathbf{a q})+mathbf{H}_{2} mathbf{S}(mathbf{a q}) rightarrow mathbf{S}(mathbf{s})+ ) ( mathbf{2 H}^{+}(mathbf{a q})+mathbf{2} mathbf{C l}^{-}(mathbf{a q}) ) The rate equation for this reaction is ( = ) ( mathbf{k}left[mathbf{C l}_{2}right]left[mathbf{H}_{2} mathbf{S}right] ) Which of these mechanisms is/are consistent with this rate equation? ( (mathrm{A}) mathrm{Cl}_{2}+mathrm{H}_{2} S rightarrow mathrm{H}^{+}+mathrm{Cl}^{-}+mathrm{Cl}^{+}+ ) ( mathbf{H S}^{-}(text {slow }) ) ( mathbf{C l}^{+}+mathbf{H S}^{-} rightarrow mathbf{H}^{+}+mathbf{C l}^{-}+mathbf{S}(text { fast }) ) (B) ( mathbf{H}_{2} mathbf{S} Leftrightarrow mathbf{H}^{+}+mathbf{H S}^{-} ) (fast equilibrium) ( mathbf{C l}_{2}+mathbf{H S}^{-} rightarrow mathbf{2 C l}^{-}+mathbf{H}^{+}+mathbf{S}(text { slow }) ) A. B only B. Both A and B c. Neither A nor B D. A only |
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228 | The rate constant of a reaction increases by 3 times for every ( 10^{0} C ) rise in temperature uniformly, in the range of ( 20^{circ} mathrm{C} ) to ( 80^{circ} mathrm{C} ). If the rate constant at ( 30^{circ} mathrm{C} ) is ( mathrm{K}, ) then what is its value at ( 60^{0} C ? ) ( A cdot 9 K ) в. 27К ( c cdot 6 k ) D. 81K |
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229 | The half-life period for a first order reaction is: A. Independent of concentration B. Proportional to concentration c. Inversely proportional to concentration D. Inversely proportional to the square of the concentration |
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230 | The activation energy of a reaction is zero. The rate constant of reaction: A. increases with increase of temperature B. decreases with decrease of temperature c. decreases with increase of temperature D. independent of temperature |
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231 | Which of the following statement is incorrect about the reaction? A. The degree of decomposition is ( N_{2} O_{5}, alpha=1-e^{-K_{1} cdot t} ) B. The forward reaction is endothermic C. The forward reaction is exothermic D. The half-life of reaction is ( frac{l n 2}{K_{1}} ) |
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232 | In the Ostwald process ( 4 N H_{3}+ ) ( 4 O_{2} rightleftharpoons 4 N O+6 H_{2} O ) platinum is used as a catalyst. If the amount of catalyst is increased when the system has reached equilibrium, which of the following will occur A. More ( N O ) and ( H_{2} O ) will form B. More ( N H_{3} ) and ( O_{2} ) will form c. Reaction rate will be increased D. No change will be evident |
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233 | Question 8. The rate constant of the chemical reaction doubled for an increase of 10 K in absolute temperature from 295 K. Calculate Eq. @ To calculate Ea, apply Arrhenius equation, log K2 Ea 1 1 on 109 2.303LT, TI |
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234 | Question 11. The reaction between H2(g) and O2(g) is highly feasible yet allowing the gases to stand at room temperature in the same vessel does not lead to the formation of water. Explain. . |
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235 | ( boldsymbol{H}_{2}+boldsymbol{B} boldsymbol{r}_{2} rightarrow boldsymbol{2} boldsymbol{H} boldsymbol{B} boldsymbol{r} ) The rate law is ( frac{d x}{d t}=kleft[H_{2}right]^{1 / 2}left[B r_{2}right]^{1 / 2}: ) On increasing the concentration of ( B r_{2} ) four times, by how much times the rate of reaction will change? ( A cdot 2 ) B. 3 ( c cdot 4 ) D. |
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236 | Units of rate constant of a first order reaction is : A . mole.lit” B. lit.mole c. mole.sec ( ^{-1} ) D. ( sec ^{-1} ) |
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237 | The equilibrium constant for the reaction ( boldsymbol{H}_{2}(boldsymbol{g})+boldsymbol{S}(s) rightleftharpoons boldsymbol{H}_{2} boldsymbol{S}(boldsymbol{g}) ) is 18.5 at ( 925 K ) and 9.25 at ( 1000 K ) respectively. Calculate the enthalpy of the reaction. |
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238 | In a reaction, 5 g ethyl acetate is hydrolyzed per litre in the presence of dil. HCl in 300 min.lf the reaction is of the first order and the initial concentration of ethyl acetate is 22 g ( L^{-1}, ) the rate constant of the reaction is: A. ( k=8.6 times 10^{-4} min ^{-1} ) В. ( k=1.4 times 10^{-4} min ^{-1} ) c. ( k=6.9 times 10^{-4} min ^{-1} ) D. None of these |
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239 | 2 7 Consider the Arrhenius equation aiven below and mark the correct option. k= A e RT (a) Rate constant increases exponentially with increasing activation energy and decreasing temperature (b) Rate constant decreases exponentially with increasing activation energy and decreasing temperature (c) Rate constant increases exponentially with decreasing activation energy and decreasing temperature (d) Rate constant increases exponentially with decreasing activation energy and increasing temperature |
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240 | The time required for the completion of first order reaction is: A . Infinity B. Thrice that of time required for 90% completion c. ( 3 / 2 ) that of time required for ( 90 % ) completion D. ten times that of time required for ( 90 % ) completion |
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241 | If the concentration of reactants is increased by ‘X’, the rate constant ( mathrm{K} ) becomes: ( mathbf{A} cdot e^{left(frac{K}{X}right)} ) B . ( frac{K}{X} ) c. ( K ) D. ( frac{x}{K} ) |
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242 | The rate constant is given by the equation ( boldsymbol{K}=boldsymbol{P} boldsymbol{Z} boldsymbol{e}^{-boldsymbol{E} / boldsymbol{R} boldsymbol{T}} . ) Which factor should register a decrease for the reaction to proceed more rapidly? A . T B. z ( c cdot E ) D. |
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243 | A substance ‘A decomposes in solution following the first order kinetics. Flask contains I L of 1 M solution of A and flask II contains ( 100 mathrm{mL} ) of ( 0.6 mathrm{M} ) solution After ( 8 mathrm{hr} ), the concentration, of ( mathrm{A} ) in flask I becomes 0.25 M. What will be the time for concentration of ( A ) in flask II to become 0.3 M? A. ( 0.4 mathrm{hr} ) B. 2.4 hr c. ( 4.0 mathrm{hr} ) D. Unpredictable as rate constant is not given |
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244 | A radioactive material of half-life ( boldsymbol{T} ) was produced in a nuclear reactor at different instants, the quantity produced second time was twice of that produced first time. If now their present activities are ( A_{1} ) and ( A_{2} ) respectively then their age difference equals: ( ^{mathbf{A}} cdot frac{T}{ln 2}left|ln frac{A_{1}}{A_{2}}right| ) ( ^{mathbf{B}} cdot quad^{ }left|ln frac{A_{1}}{A_{2}}right| ) ( c ) [ frac{T}{ln 2}left|ln frac{A_{2}}{2 A_{1}}right| ] D. [ T mid ln frac{A_{2}}{2 A_{1}} ] |
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245 | How does temperature affect reaction rate? A. It usually increases it B. It always decreases it C . It always increases it D. Reaction rate is independent of temperature E. It usually decreases it |
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246 | The choices below are some of the proposed steps of a reaction mechanism. Which step is least likely to be the ratedetermining step of the mechanism? A. ( J+K rightarrow J K ) B. ( 2 J K+4 L rightarrow 2 J L+2 K L ) c. ( K L+M N rightarrow K M+M L ) D. ( 2 K M rightarrow K_{2}+2 M ) |
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247 | What names apply to chemical species corresponding to locations 1 and 2 on this reaction coordinate diagram? Location 1 Location 2 |
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248 | In the first order reaction, ( boldsymbol{A}(boldsymbol{g}) rightarrow ) ( B(g)+C(g), ) at constant volume and temperature, the initial pressure of ( boldsymbol{A} ) is ( 11200 P a ) and the total pressure at the end of 16 minutes is 14667 Pa. Calculate the half life period of reaction. |
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249 | ( boldsymbol{a} boldsymbol{A}+boldsymbol{b} boldsymbol{B} rightarrow operatorname{Product}, boldsymbol{d} boldsymbol{x} / boldsymbol{d} boldsymbol{t}=boldsymbol{k}[boldsymbol{A}]^{boldsymbol{a}}[boldsymbol{B}]^{b} ) If concentration of ( boldsymbol{A} ) is doubled, rate is four times. If concentration of ( B ) is made four times, rate is doubled. What is relation between rate of disappearance of ( A ) and that of ( B ? ) ( mathbf{A} cdot-{d[A] / d t}=-{d[B] / d t} ) B . ( -{d[A] / d t}=-{4 d[B] / d t} ) ( mathbf{c} cdot-{4 d[A] / d t}=-{d[B] / d t} ) D. None of these |
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250 | Which of letter shows the enthalpy change ( (triangle boldsymbol{H}) ) of the reaction? ( A ) B. ( c . c ) ( D ) E. |
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251 | Which of the following is pseudounimolecular reaction? A. ( 2 H_{2} O_{2} rightarrow 2 H_{2} O+O_{2} ) в. ( C_{6} H_{5} N_{2} C l+H O H longrightarrow C_{6} H_{5} O H+N_{2}+H C l ) c. ( C H_{3} C O O C_{2} H_{5}+N a O H rightarrow C H_{3} C O O N a+ ) ( C_{2} H_{5} O H ) D. ( 20_{3} rightarrow 30_{2} ) |
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252 | What happens to the half life period for a first order reaction, if the intial concentration of the reactants is increased? |
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253 | For a reaction following first-order kinetics, which of the following statements is/are correct? A. The time taken for the completion of ( 50 % ) of the reaction is ( t_{1 / 2} ) B. A plot of the reciprocal of the concentration of the reactants against time gives a straight line. c. The degree of dissociation is equal to ( 1-e^{-k t} ) D. A plot of ( [A]_{0} /[A] ) versus time gives a straight line |
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254 | Which of the following reactions will not have fractional order for ( boldsymbol{A}_{2} ) or ( boldsymbol{B}_{2} ? ) ( mathbf{A} cdot A_{2} rightleftharpoons A+A(text { fast }) ) [ begin{array}{l} A+B_{2} rightleftharpoons A B+B text { (slow) } \ A+B rightleftharpoons A B text { (fast) } end{array} ] B ( cdot A_{2} rightleftharpoons C ) (slow) [ C+B_{2} rightleftharpoons D text { (fast) } ] [ D+A_{2} rightleftharpoons text { Product } ] C. ( B_{2} rightleftharpoons B+B ) (fast) [ begin{array}{l} A_{2}+B rightleftharpoons A B+A text { (slow) } \ A B longrightarrow text { Products (fast) } end{array} ] D. None of the above |
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255 | dentify the type of reaction indicated by ( D ) in the diagram. A. Uncatalyzed exothermic B. Catalyzed exothermic c. Catalyzed endothermic E. Reversible |
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256 | Collision frequency of a gas at 1 atm pressure is ( Z ). Its value at 0.5 at ( m ) will be: A ( .0 .25 Z ) в. ( 2 Z ) c. ( 0.50 Z ) D. ( z ) |
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257 | For the reaction ( boldsymbol{H}_{2}(boldsymbol{g})+boldsymbol{B} boldsymbol{r}_{2}(boldsymbol{g}) rightarrow ) ( 2 H B r(g), ) the experiment data suggested that ( r=kleft[H_{2}right]left[B r_{2}right]^{1 / 2} . ) The molecularity and order of the reaction are respectively: A. 2, 3/2 B. 3/2,3/2 c. Not defined, 3/2 D. ( 1,1 / 2 ) |
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258 | NaOH can’t be stored in ( mathbf{A} cdot ) Al vessel B. Zn vessel c. Both a and D. None of these |
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259 | In the Arrhenius equation ( k=A e^{E / R T} ) rate will be constant at: A . infinite ( T ) or zero ( E_{a} ) B. infinite ( E_{a} ) or zero ( T ) C. infinite ( E_{a} ) and zero ( T ) D. none of these |
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260 | ( boldsymbol{T}_{50} ) (Half-life period) of first – order reaction is 10 minute. Starting with ( 10 m o l L^{-1}, ) rate after 20 minute is : A ( cdot 0.0693 m o l L^{-1} min ^{-1} ) В. ( 0.0693 times 2.5 ) molL( ^{-1} ) min ( ^{-1} ) ( mathbf{c} cdot 0.0693 times 5 m o l L^{-1} min ^{-1} ) D. ( 0.0693 times 10 ) molL( ^{-1} ) min ( ^{-1} ) |
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261 | In ( _{text {十一一一一一一一一一一, }} ) a reaction product is itself a catalyst for that reaction leading to positive feedback. A. Autocatalysis B. Catalysis c. Pressure jump D. Fast reactions |
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262 | The reaction ( N_{2} O_{5} quadleft(text { In } quad C C l_{4}right) rightarrow ) ( 2 N O_{2}+1 / 2 quad O_{2}(g) ) is first order in ( N_{2} O_{5} ) with rate constant ( 6.2 times ) ( 10^{-4} S^{-1} . ) What is the value of rate of reaction when ( left[boldsymbol{N}_{mathbf{2}} boldsymbol{O}_{boldsymbol{5}}right]= ) ( begin{array}{lll}mathbf{1 . 2 5} & text { mole } & boldsymbol{L}^{-1}end{array} ) ( begin{array}{ll}text { A } cdot 7.75 times 10^{-4} & L^{-1} S^{-1}end{array} ) B. ( 6.35 times 10^{-3} quad L^{-1} S^{-1} ) ( begin{array}{ll}text { C. } 5.15 times 10^{-5} & L^{-1} S^{-1}end{array} ) D. 3.85 times 10 ( ^{-4} quad L^{-1} S^{-1} ) |
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263 | What is half-life of a reaction? Derive formula for finding out half-life from first order rate reaction. |
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264 | A gas is formed by the reaction between marble pieces and dilute ( boldsymbol{H} boldsymbol{C l} ) (a) Which gas is formed as a result of this reaction? (b) Write the balanced chemical equation for this reaction. (c) Suggest two ways of increasing the speed of the chemical reaction. |
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265 | idy TO De eguar . 10 Consider the graph given in figure. Which of the fou not show instantaneous rate of reaction at 405? graph given in figure. Which of the following options does V2 H 20 30 40 50 50-30 50 – 30 40-30 40 – 20 |
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266 | The rate of the first order reaction is ( 0.69 times 10^{-2} ) mol ( L^{-1} ) min ( ^{-1} ) and the initial concentration is ( 0.2 m o l L^{-1} ). The half life period is: A . ( 1205 s ) в. 330 c. ( 600 s ) D. ( 1 s ) |
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267 | Question 18. For a first order reaction, show that time required for 99% completion is twice the time required for the completion of 90% of reaction. hely () Findt for the 99% completion of reaction by using, t = = g.t = 2.303 logo 2 a – X (ii) Similarly findt for 90% completion. (iii) Compare the above two values to find a relation betweent 99% and 90% |
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268 | The conversion ( A rightarrow B ) follows second order kinetics. Doubling, the concentration of ( boldsymbol{A} ) will increase the rate of formation of ( boldsymbol{B} ) by a factor of: ( A cdot 2 ) B. 4 c. 0.5 D. 0.25 |
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269 | In a first order reaction, ( 75 % ) of the reactants disappeared in 1.386 hr. What is the rate constant? A ( cdot 3.6 times 10^{-3} s^{-1} ) В. ( 2.7 times 10^{-4} s^{-1} ) c. ( 72 times 10^{-3} s^{-1} ) D. ( 1.8 times 10^{-3} s^{-1} ) |
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270 | The reaction at hydrogen and iodine monochloride is represented by the equation is ( boldsymbol{H}_{2}(boldsymbol{g})+boldsymbol{2} boldsymbol{I} boldsymbol{C l}(boldsymbol{g}) rightarrow boldsymbol{2} boldsymbol{H} boldsymbol{C l}(boldsymbol{g})+boldsymbol{I}_{2}(boldsymbol{g}) ) This reaction is first order in ( boldsymbol{H}_{2}(boldsymbol{g}) ) and also first – order in ICI(g). which of these proposed mechanism can be consistent with the given information about this reaction ? Mechanism I ( : boldsymbol{H}_{2}(boldsymbol{g})+2 boldsymbol{I} boldsymbol{C l}(boldsymbol{g}) rightarrow ) ( 2 H C l(g)+I_{2}(g) ) ( |: boldsymbol{H}_{2}(boldsymbol{g})+boldsymbol{I} boldsymbol{C l}(boldsymbol{g}) stackrel{s l o w}{rightarrow} ) Mechanism ( boldsymbol{H} boldsymbol{C l}(boldsymbol{g})+boldsymbol{H} boldsymbol{I}(boldsymbol{g}) ) ( boldsymbol{H I}(boldsymbol{g})+boldsymbol{I} C l(boldsymbol{g}) stackrel{f a s t}{rightarrow} boldsymbol{H} C l(boldsymbol{g})+boldsymbol{I}_{2}(boldsymbol{g}) ) A . I only в. ॥ only c. Both I and II D. Neither I nor I |
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271 | For the reaction ( 2 mathrm{A}+mathrm{B} rightarrow mathrm{C}+3 mathrm{D} ) which of the following is / are correct? This question has multiple correct options ( ^{mathbf{A}} cdot+frac{Delta[D]}{Delta t}=-frac{1}{3} frac{Delta[C]}{Delta t} ) B. ( +frac{Delta[C]}{Delta t}=-frac{1}{2} frac{Delta[A]}{Delta t} ) c. ( -frac{1}{2} frac{Delta[B]}{Delta t}=-frac{1}{3} frac{Delta[D]}{Delta t} ) D. ( frac{Delta[C]}{Delta t}=+frac{1}{3} frac{Delta[D]}{Delta t} ) |
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272 | The catalytic decomposition of ( boldsymbol{H}_{2} boldsymbol{O}_{2} ) was studied by titrating it at different intervals with ( K M n O_{4} ) and the following data were obtained: ( boldsymbol{t}(text {seconds}) ) ( mathbf{0} ) ( boldsymbol{V} boldsymbol{o} boldsymbol{f} boldsymbol{K} boldsymbol{M} boldsymbol{n} boldsymbol{O}_{4}(boldsymbol{m} boldsymbol{L}) quad mathbf{2 2 . 8} quad mathbf{1 3 . 8} ) Calculate the velocity constant for the reaction assuming it to be a first order reaction. |
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273 | In a chemical reaction ( boldsymbol{X} rightarrow boldsymbol{Y} ), it is found that the rate reaction doubles when the concentration of ( boldsymbol{X} ) is increased four times. The order of the reaction with respect to ( boldsymbol{X} ) is: A . 1 B. 2 ( c cdot 2 ) D. ( frac{1}{2} ) |
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274 | Total order of reaction ( boldsymbol{X}+boldsymbol{Y} rightarrow boldsymbol{X} boldsymbol{Y} ) is 3 The order of reaction with respect to ( X ) is 2. State the differential rate equation for the reaction. ( ^{mathbf{A}} cdot-frac{d[X]}{d t}=k[X]^{0}[Y]^{3} ) в. ( -frac{d[X]}{d t}=k[X]^{3}[Y]^{0} ) ( ^{mathrm{c}} cdot frac{d[X]}{d t}=k[X]^{2}[Y] ) D. ( -frac{d[X]}{d t}=k[X][Y]^{2} ) |
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275 | Rate of formation of ( boldsymbol{S} boldsymbol{O}_{3} ) according to the reaction ( 2 S O_{2}+O_{2} rightarrow ) ( mathbf{2 S O}_{3} quad ) is ( quad mathbf{1 . 6} times mathbf{1 0}^{-mathbf{3}} mathbf{k g} quad mathbf{m i n}^{-mathbf{1}} ) Hence rate at which ( S O_{2} ) reacts is: A . ( 1.6 times 10^{-3} mathrm{kg} ) min ( ^{-1} ) В. ( 8.0 times 10^{-4} k g ) min( ^{-1} ) c. ( 3.2 times 10^{-3} k g ) min( ^{-1} ) D. ( 1.28 times 10^{-3} mathrm{kg} ) min( ^{-1} ) |
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276 | unchanged as there is no change in stability ITU energy of a chemical reaction can be determined by ……. Q. 3 Activation energy of a chemical (a) determining the rate constant at standard temperature (b) determining the rate constant at two temperatures (c) determining probability of collision (d) using catalyst |
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277 | For a first order reaction, if ( boldsymbol{K}_{mathbf{1}}: boldsymbol{K}_{mathbf{2}}: boldsymbol{K}_{mathbf{3}} ) is ( 1: 2: 3, ) then which of the following statement(s) is/are incorrect? ( left([boldsymbol{A}]_{mathbf{0}}=right. ) ( mathbf{1} boldsymbol{M}) ) A. At time ( t_{infty} ), [C] is ( 2 / 3 ) M. B . ( [B]_{t}>[C]_{t} ) C. When ( [A]_{t}=1 / 2 M, ) then ( [D]=1 M ) D・ ( [A]_{t}+frac{left[B l_{t}right.}{2}+frac{[C]_{t}}{2}+frac{left[D_{l t}right.}{4}=1 M ) |
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278 | Arsine produces hydrogen gas on heating. The pressure of produced hydrogen was measured, at consant volume and temperature, as follows: Time ( quad ) o ( quad 5.5 quad 6.5 ) (hours) Pressure ( quad ) 0.965 ( quad ) 1.060 ( quad 1.076 ) ( (a+m) ) |
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279 | Question 13. Oxygen is available in plenty in air yet fuels do not burn by them selves at room temperature. Explain. |
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280 | Statement – I : The molecularity of the reaction ( boldsymbol{H}_{2}+boldsymbol{B} boldsymbol{r}_{2} rightarrow 2 mathrm{HBr} ) is 2 Statement – II: The order of this reaction is ( 3 / 2 ) A. Both statements are true Statement- – I is correct explanation of Statement- – B. Both statements are true but statement- -II is not correct explanation of Statement- – c. Statement-lis true but Statement- -II is false D. Statement- – lis false but Statement – / l is true |
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281 | The rate equation for a reaction, ( boldsymbol{A} longrightarrow ) ( B ) is ( r=k[A]^{0} . ) If the initial concentration of the reactant is ( a ) mol.dm ( ^{-3} ), the half-life period of the reaction is: A ( cdot frac{a}{2 k} ) в. ( frac{k}{a} ) c. ( frac{a}{k} ) D. ( frac{2 a}{k} ) |
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282 | In a reaction involving one single reactant, the fraction of the reactant consumed may be defined as ( boldsymbol{f}= ) ( left(1-frac{C}{C_{0}}right) ) where ( C_{0} ) and ( C ) are the concentrations of the reactant at the after time, t. For a first order reaction: A ( cdot frac{d f}{d t}=k(1-f) ) B. ( -frac{d f}{d t}=k f ) c. ( -frac{d f}{d t}=k(1-f) ) D. ( frac{d f}{d t}=k f ) |
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283 | The order of reaction for which half-life period is independent of initia concentration is: A. zero B. first c. second D. third |
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284 | From the rate expression for the following reactions, determine their order of reaction and the dimensions of the rate constants. (i) ( 2 N O(g) rightarrow N_{2} O(g) ; quad ) Rate ( = ) ( boldsymbol{k}[boldsymbol{N} boldsymbol{O}]^{2} ) (ii) ( boldsymbol{H}_{2} boldsymbol{O}_{2}(boldsymbol{a} boldsymbol{q})+boldsymbol{3} boldsymbol{I}^{-}(boldsymbol{a} boldsymbol{q})+boldsymbol{2} boldsymbol{H}^{+} rightarrow ) ( 2 H 2 O(I)+3 I ; quad R a t e=kleft[H_{2} O_{2}right]left[I^{-}right] ) (iii) ( boldsymbol{C H}_{3} boldsymbol{C H O}(boldsymbol{g}) rightarrow boldsymbol{C H}_{4}(boldsymbol{g})+ ) ( boldsymbol{C O}(boldsymbol{g}) ; quad boldsymbol{R} boldsymbol{a} boldsymbol{t e}=boldsymbol{k}left[boldsymbol{C} boldsymbol{H}_{3} boldsymbol{C H O}right]^{3 / 2} ) (iv) ( C_{2} H_{5} C l(g) rightarrow C_{2} H_{4}(g)+ ) ( boldsymbol{H} boldsymbol{C l}(boldsymbol{g}) ; quad boldsymbol{R} boldsymbol{a} boldsymbol{t} e=boldsymbol{k}left[boldsymbol{C}_{2} boldsymbol{H}_{5} boldsymbol{C l}right] ) |
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285 | The reaction ( A rightarrow B ) follows first-order kinetics. The time taken for 0.8 mol of ( A ) to produce 0.6 mol of ( mathrm{B} ) is 1 hr. What is the time taken for the conversion of 0.9 mol of ( A ) to produce 0.675 mol of B? ( A cdot 1 h r ) B. 0.5 hr c. ( 0.25 mathrm{hr} ) ( D cdot 2 h r ) |
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286 | The value of rate of a pseudo first order reaction depends upon: A. the concentration of both the reactants present in the reaction B. the concentration of the reactant present in small amount c. the concentration of the reactant present in excess D. the value of ( Delta H ) of the reaction |
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287 | The rate of change of concentration of any one of the reactants or products at a particular moment of time is known as the ? A. Average rate B. Instantaneous rate c. Rate of disintegration D. None of these |
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288 | ( 99 % ) of a first order reaction, was completed in 32 minute. When will ( 99.9 % ) of the reaction complete? A. 50 minute B. 46 minute c. 49 minute D. 48 minute |
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289 | The rate constant of the reaction ( boldsymbol{A} rightarrow ) ( 2 B ) is ( 1.0 times ! 0^{-3} ) mol ( l i t^{-1} ) min ( ^{-1}, ) if the initial concentration of ( boldsymbol{A} ) is 1.0 mole ( l i t^{-1}, ) what would be the concentration of ( B ) after 100 minutes? A. ( 0.1 mathrm{mol} ) lit( ^{-1} ) B. 0.2 mol lit ( ^{-1} ) c. 0.9 mol lit ( ^{-1} ) D. 1.8 mollit( ^{-1} ) |
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290 | Why does the probability curve become narrower when gas particles are more massive? A. The gas particles can travel at higher speeds B. The gas particles are less likely to travel at slower speeds C. The gas particles are more likely to travel at higher speeds D. The gas particles can not travel at higher speeds E. There are more collisions between gas particles |
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291 | The terms order and molecularity are common in chemical kinetics. (a) What do you mean by order and molecularity? (b) (i) Write two factors influencing rate of a reaction. (ii) Write Arrhenius equation. |
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292 | А-В Question 10. For a general reaction, A B , plot of concentration of A vs time is given in figure. Answer the following question on the basis of this graph. (i) What is the order of the reaction? (ii) What is the slope of the curve? (iii) What are the units of rate constant? 6 7ern order Conc. of A |
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293 | The reaction ( boldsymbol{C H}_{mathbf{3}}-boldsymbol{C H}_{mathbf{2}}-boldsymbol{N O}_{mathbf{2}}+ ) ( boldsymbol{O H}^{-} rightarrow boldsymbol{C H}_{3}-boldsymbol{C H}-boldsymbol{N O}_{2}+boldsymbol{H}_{2} boldsymbol{O} ) obeys the rate law for pseudo first order kinetics in the presence of a large excess of hydroxide ion. If 1 percent of nitro ethane undergoes reaction in half a minute when the reactant concentration is ( 0.002 M, ) the pseudo first order rate constant is : A ( cdot 2 times 10^{-2} min ^{-1} ) B . ( 3 times 10^{-2} ) min ( ^{-1} ) c. ( 5 times 10^{-2} ) min ( ^{-1} ) D. ( 7 times 10^{-2} ) min ( ^{-1} ) |
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294 | Define collision frequency. Give an example for Pseudo-first order reaction. | 12 |
295 | In a homogeneous reaction ( boldsymbol{A} longrightarrow boldsymbol{B}+ ) ( C+D ) the initial pressure was ( P_{0} ) and after time ( t ) it was ( P . ) Expression for rate constant ( k ) in terms of ( P_{0}, P ) and ( t ) will be: A ( quad k=frac{2.303}{t} log frac{2 P_{0}}{3 P_{0}-P} ) В. ( _{k=} frac{2.303}{t} log frac{2 P_{0}}{P_{0}-P} ) c. ( _{k=} frac{2.303}{t} log frac{3 P_{0}-P}{2 P_{0}} ) D. ( _{k}=frac{2.303}{t} log frac{2 P_{0}}{3 P_{0}-2 P} ) |
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296 | For the reaction ( boldsymbol{O}_{3(g)}+boldsymbol{O}_{(g)} rightarrow mathbf{2} boldsymbol{O}_{2(g)} ) if the rate law expression is, rate ( = ) ( boldsymbol{K}left[boldsymbol{O}_{3}right][boldsymbol{O}] ) the molecularity and order of the reaction are: A . 2 and 2 B. 2 and 1.33 c. 2 and 1 D. 1 and 2 |
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297 | For a reaction ( boldsymbol{P}+boldsymbol{Q} rightarrow mathbf{2} boldsymbol{R}+boldsymbol{S} . ) Which of the following statements is incorrect? A. Rate of disappearance of ( P= ) Rate of appearance of B. Rate of disappearance of ( P=2 times ) Rate of appearance of ( R ) c. Rate of disappearance of ( P= ) Rate of disappearance of ( Q ) D. Rate of disappearance of ( Q=frac{1}{2} times ) Rate of appearance of ( R ) |
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298 | In a milk at ( 37^{circ} C ), Lactobacillus acidophilus has a generation time of about 75 minutes. Calculate the population relative to the initial value at 30,60,75,90 and 150 minutes. |
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299 | Consider the following first order competing reactions: ( boldsymbol{X} stackrel{boldsymbol{k}_{1}}{rightarrow} boldsymbol{A}+boldsymbol{B} quad ) and ( quad boldsymbol{Y} quad underline{k}_{2} quad boldsymbol{C}+ ) ( D ) If ( 50 % ) of the reaction of ( X ) was completed when ( 96 % ) of the reaction of ( Y ) was completed, the ratio of their rate constants ( left(k_{2} / k_{1}right) ) is: A . 4.0 B. 6.8 c. 3. D. 4.6 |
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300 | State whether the statement is True or False: Two molecules can react only if they have a correct relative orientation. |
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301 | increases effective collisions without increasing average energy. A. An increase in the reactant concentration B. An increase in the temperature c. A decrease in pressure D. Catalysts E ( . p H ) |
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302 | The half life of a first order reaction is 69.35 seconds, the value of rate constant of the reaction is: A ( cdot 1.0 s^{-1} ) B. ( 0.1 s^{-1} ) ( c cdot 0.01 s^{-1} ) D. ( 0.001 s^{-1} ) |
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303 | A certain reactant ( X O_{3}^{-} ) is getting converted to ( X_{2} O_{7} ) in solution. The rate constant of this reaction is measured by titrating a volume of the solution with a reducing agent which reacts only with ( X O_{3}^{-} ) and ( X_{2} O_{7} . ) In this process of reduction both the compounds converted to ( X^{-} . ) At ( t=0, ) the volume of the reagent consumed is ( 30 mathrm{mL} ) and at ( mathrm{t} ) ( =9.212 mathrm{min.} ) the volume used up is 36 mL. Find the rate constant(in ( h r^{-1} ) ) of the conversion of ( boldsymbol{X} boldsymbol{O}_{3}^{-} ) to ( boldsymbol{X}_{2} boldsymbol{O}_{7} ? ) Assuming reaction is of 1st order. (Given that ( ln 10=2.303, log 2=0.30 ) ). |
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304 | The rate of reaction w.r.t reactants is indicated by a negative sign A. True B. False |
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305 | Rate law for the following reaction; Ester ( +boldsymbol{H}^{+} rightleftharpoons ) Acids ( + ) Alcohol; is ( frac{d x}{d t}=k[text { ester }]^{1}left[H^{+}right]^{0} . ) What would be the effect on the rate if concentration of ( boldsymbol{H}^{+} ) ion is doubled? A. Same B. Doubled c. Half D. Data insufficient |
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306 | The rate constant for a zero order reaction is ( 2 times 10^{-2} ) mol ( L^{-1} s e c^{-1}, ) if the concentration of the ractant after ( 25 sec ) is ( 0.25 M, ) calculate the initial concentration A ( .0 .75 M ) B. ( 1.5 M ) c. 0.375 D. None of these |
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307 | Assertion The rate of reaction increases generally by 2 to 3 times for every ( 10^{circ} mathrm{C} ) rise in temperature. Reason An increase in temperature increases the coliision frequency. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is correct but Reason is incorrect D. Assertion is incorrect but Reason is correct |
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308 | If the activation energy of a reaction is ( 480.9 k J ) mol ( ^{-1} ), calculate the fraction of molecules at ( 400^{circ} C ) which have enough energy to react to form the products. |
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309 | If the first order reaction involves gaseous reactant and gaseous products the units of its rate are: A . atm B. ( a t m-s e c ) c. ( a t m-s e c^{-1} ) D. ( a t m^{2}-s e c^{2} ) |
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310 | A carbon sample from the frame of picture gives 7 counts of ( C^{14} ) per minute per gram of carbon. If freshly cut wood gives 15.3 counts of ( C^{14} ) per minute, calculate the age of frame. ( left(t_{1 / 2} text { of } C^{14}=right. ) 5570 years A . 6286 years B. 5527 years c. 5570 years D. 4570 years |
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311 | What is order of reaction? Write unit of rate constant ( K ) for the zero order, first order and second order reaction. |
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312 | Statement 1: The temperature of a substance always increases as heat energy is added to the system. Statement 2: The average kinetic energy of the particles in the system increases with an increase in temperature. A. Statement 1 and Statement 2 are correct and Statement 2 is the correct explanation of Statement 1 B. Both the Statement 1 and Statement 2 are correct and Statement 2 is NOT the correct explanation of Statement 1. c. Statement 1 is correct but Statement 2 is not correct. D. Statement 1 is not correct but Statement 2 is correct. E. Both the Statement 1 and Statement 2 are not correct. |
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313 | For the reaction ( 5 B r^{-1}(a q)+ ) ( 6 H^{+}(a q)+B r O_{3}^{-}(a q) rightarrow 3 B r_{2}(a q)+ ) ( mathbf{3} boldsymbol{H}_{2} boldsymbol{O}(boldsymbol{l}) ) ( mathrm{f},-frac{Deltaleft[B r O_{3}^{-}right]}{Delta t}= ) ( 0.01 m o l L^{-1} m i n^{-1}, frac{Deltaleft[B r_{2}right]}{Delta t} ) in ( operatorname{mol} L^{-1} min ^{-1} ) is : A. 0.0 B. 0.3 c. 0.03 D. 0.005 |
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314 | The conversion of vinyl allyl ether to pent-4-enol follows a certain kinetics. The following plot is obtained for such reaction.The order for the reaction is: 4. zercor B. ( c ) 2 |
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315 | The following data were obtained during the first order thermal decomposition of ( S O_{2} C l_{2} ) at constant volume [ boldsymbol{S} boldsymbol{O}_{2} boldsymbol{C l}_{2(boldsymbol{g})} rightarrow boldsymbol{S} boldsymbol{O}_{2(boldsymbol{g})}+boldsymbol{C l}_{2(boldsymbol{g})} ] Expt Time / ( S^{-1} quad ) Total pressure/ atm 0.5 ( 0 . ) when the total pressure is 0.65 atm then the rate constant of reaction is if ( a=p i, ) and ( a-x=2 p i-P t ) A. 2.0 ( times 10^{-3} mathrm{S}^{-1} ) в. 2.12 ( times 10^{-3} S^{-1} ) c. ( 2.23 times 10^{-3} S^{-1} ) D. 2.34 ( times 10^{-3} S^{-1} ) |
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316 | Triple point temperature for water is nearly: A . ( 273.16 K ) в. ( 373.16 K ) ( mathbf{c} cdot 100^{circ} mathrm{C} ) D. ( 444.6^{circ} mathrm{C} ) |
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317 | Question 1. State a condition under which a bimolecular reaction is kinetically first order reaction. |
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318 | Which of the following statement is true for the reaction, ( boldsymbol{H}_{2}+boldsymbol{B} boldsymbol{r}_{2} rightarrow boldsymbol{2} boldsymbol{H} boldsymbol{B} boldsymbol{r} ) The rate law is ( frac{boldsymbol{d} boldsymbol{x}}{boldsymbol{d} boldsymbol{t}}=boldsymbol{k}left[boldsymbol{H}_{2}right]left[boldsymbol{B} boldsymbol{r}_{2}right]^{1 / 2} ) A. order of reaction is 1.5 B. molecularity of the reaction is 2 c. by increasing the concentration of ( B r_{2} ) four times the rate of reaction is doubled D. all the above are correct |
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319 | ( A ) follows the first-order reaction. ( (A) longrightarrow ) product. The concentration of ( A ) changes from ( 0 . ) M to ( 0.025 mathrm{M} ) in 40 minutes. Find the rate of reaction of ( A ) when concentration of ( A ) is ( 0.01 mathrm{M} ? ) A ( cdot 3.47 times 10^{-4} mathrm{M} min ^{-1} ) В. ( 3.47 times 10^{-5} mathrm{M} min ^{-1} ) c. ( 1.73 times 10^{-4} mathrm{M} min ^{-1} ) D. ( 1.73 times 10^{-3} mathrm{M} min ^{-1} ) |
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320 | What do you understand by the ‘order of a reaction’? Identify the reaction order from each of the following units of reaction rate constant: (i) ( L^{-1} ) mol ( s^{-1} ) (ii) ( L m o l^{-1} s^{-1} ) |
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321 | Following reaction can take place in both direction ( A stackrel{k_{1}}{_{k_{2}}} B, ) It is given that for the forward reaction: ( [mathrm{B}] ) Rate ( 0.01 M quad 1 times 10^{-2} M s^{-1} ) ( 0.02 M quad 2 times 10^{-2} M s^{-1} ) Hence, net reaction rate of B is: Rate ( mathbf{A} cdot k_{1} ) ( mathbf{B} cdot k_{1}-k_{2} ) ( mathbf{c} cdot k_{1}[A]-k_{2} ) D. none of these |
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322 | In the thermal decomposition of ( N_{2} O ) at ( 830 mathrm{K}, ) the time required to decompose half of the reactant was 263 sec at the initial pressure ( 290 mathrm{mm} . ) It takes 212 sec to decompose half of the reactant if initial pressure was ( 360 mathrm{mm} ). What is the order of the reaction? Also calculate ( t_{1 / 2} ) for ( N_{2} O ) decomposition if initial pressure of ( N_{2} O ) is 1 atm. A. ( O . R=2 ), Half life ( =100.2 ) sec B. ( O . R=1 ), Half life ( =10.02 ) sec c. ( O . R=4 ), Half life ( =1.002 )sec D. None of these |
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323 | A substance reacts according to ( I ) order kinetics and rate constant for the reaction is ( 1 times 10^{-2} mathrm{sec}^{-1} . ) If its initia concentration is ( 1 M ) (a) What is initial rate? (b) What is rate after 1 minute? |
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324 | For the formation of phosgene from ( C O(g) ) and chlorine, ( C O(g)+ ) ( C l_{2}(g) longrightarrow C O C l_{2}(g), ) the experimentally determined rate equation is, ( frac{boldsymbol{d}left[boldsymbol{C O C l}_{2}right]}{boldsymbol{d t}}= ) ( boldsymbol{k}[boldsymbol{C O}]left[boldsymbol{C l}_{2}right]^{3 / 2} ) Is the following mechanism consistent with the rate equation? ( (i) C l_{2} rightleftharpoons 2 C l quad ) (fast) ( (i i) C l+C O rightleftharpoons C O C l ) ( (i i i) C O C l+C l_{2} rightleftharpoons C O C l_{2}+C l ) (slow) |
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325 | Consider the reaction represented by the equation represented by the equation [ begin{array}{l} boldsymbol{C H}_{3} boldsymbol{C l}(boldsymbol{g})+boldsymbol{H}_{2} boldsymbol{O}(boldsymbol{g}) rightarrow \ boldsymbol{C H}_{3} boldsymbol{O H}(boldsymbol{g})+boldsymbol{H C l}(boldsymbol{g}) end{array} ] These kinetic data were obtained for the given reaction concentrations ( begin{array}{ll}text { Initial } & text { Initial } \ text { conc (M) } & text { conc (M) }end{array} ) Initial rate of disappearance of ( left[C H_{3} C lright] quadleft[H_{2} Oright] ) ( C H_{3} C l(M s ) 0.2 0.2 0.4 0.2 2 0.4 If ( H_{2} O ) is taken in large excess, the order of the reaction will be: ( A ) B. 2 ( c cdot 3 ) D. None of these |
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326 | ( 90 % ) of the first-order reaction is completed in 70 minutes. The velocity constant of the reaction is: A .0 .0329 B. 0.329 c. 3.29 D. 0.0293 |
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327 | A chemical reaction proceeds into the following steps Step ( mid: 2 A rightleftharpoons X ) (fast) Step II: ( boldsymbol{X}+boldsymbol{B} rightarrow boldsymbol{Y}(text { slow }) ) Step III: ( Y+B rightarrow ) Product(fast) The rate low for the overall reaction ( ^{*} ) is: |
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328 | Consider the reaction ( 2 S(g) rightarrow ) ( 3 B(g)+C(g) . ) Starting with pure ( A ) initially, the total pressure doubled in 3 hrs. The order of the reaction might possibly be? A . zero B. first c. second D. unpredictable from this data |
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329 | For a zero order chemical reaction, ( mathbf{2} boldsymbol{N} boldsymbol{H}_{3}(boldsymbol{g}) rightarrow boldsymbol{N}_{2}(boldsymbol{g})+boldsymbol{3} boldsymbol{H}_{2}(boldsymbol{g}) ) rate of reaction ( =0.1 ) atm/sec. Initially only ( N H_{3} ) is present and its pressure ( =3 ) atm. Calculate total pressure at ( t=10 mathrm{sec} ) |
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330 | On addition of ( A g N O_{3} ) to ( N a C l ) white precipitate occurs: A. instantaneously B. with a measurable speed c. slowly D. none of the above |
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331 | In a first order reaction the concentration of reactant decreases from ( 800 mathrm{mol} / mathrm{dm}^{3} ) to ( 50 mathrm{mol} / mathrm{dm}^{3} ) is ( 2 times 10^{4} ) sec. The rate constant of reaction in ( sec ^{-1} ) is: A ( cdot 2 times 10^{4} ) В. ( 3.45 times 10^{-5} ) ( mathbf{c} cdot 1.386 times 10^{-4} ) D. ( 2 times 10^{-4} ) |
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332 | An organic compound undergoes firstorder decomposition. The time taken for its decomposition to ( 1 / 8 ) and ( 1 / 10 ) of its initial concentration are ( t_{1 / 8} ) and ( t_{1 / 10} ) respectively. What is the value of ( frac{left[boldsymbol{t}_{mathbf{1} / mathbf{8}}right]}{left[boldsymbol{t}_{mathbf{1} / mathbf{1 0}}right]} times mathbf{1 0} ?left(boldsymbol{t a k e} log _{mathbf{1 0}} mathbf{2}=mathbf{0 . 3}right) ) |
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333 | Two reactions (i) ( boldsymbol{A} rightarrow ) products ( B rightarrow ) products, follow first order kinetics. The rate of the reaction (i) is doubled when the temperature is raised from ( 300 mathrm{K} ) to ( 310 mathrm{K} ). The half life for this reaction at ( 310 mathrm{K} ) is 30 minutes. At the same temperature B decomposes twice as fast as A. If the energy of activation for the reaction (ii) is half that of reaction (i), calculate the rate constant of the reaction (ii) at ( 300 mathrm{K} ) A. ( k=0.0327 min ^{-1} ) В. ( k=0.327 mathrm{min}^{-1} ) c. ( k=3.27 mathrm{min}^{-1} ) D. ( k=32.7 ) min ( ^{-1} ) |
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334 | the following graphs is correct for a zero order reaction? Reaction rate- Concentration of reactant Time – Time → slope = -k Reaction rate Concentration of reaction Time – Time |
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335 | The rate of reaction is uniform throughout the reaction. A. True B. False |
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336 | In a certain reaction, ( 10 % ) of the reactant decomposes in one hour, ( 20 % ) in two hours, ( 30 % ) in three hours, and so on. The dimension of the velocity constant (rate constant) is: ( mathbf{A} cdot H r^{-1} ) B. ( operatorname{Mol} L^{-1} h r^{-1} ) c. ( L m o l^{-1} s^{-1} ) D. Mols” |
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337 | 0.8 A graph of volume of hydrogen released vs time for the reaction between zinc and dil. HCl is given in figure. On the basis of this mark the correct option. V L / 20 30 40 50 (a) Average rate upto 40 s is (b) Average rate upto 40 s is 40 – 30 V v (d) Average rate upto 40 s is 40 – 20 (c) Average rate upto 40 s |
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338 | Q. 14 Rate law for the reaction A + 20 e law for the reaction A + 2B C is found to be Rate = k[A] [B] Concentration of reactant ‘B’ is doubled, keeping reactant ‘B’ is doubled, keeping the concentration of ‘A constant, the value of rate constant will be…….. (a) the same (b) doubled (c) quadrupled (d) halved ns (h) Rate lawon hi |
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339 | Which of the following expression is correct? ( mathbf{A} cdot frac{d[H I]}{d t}=frac{k_{3} k_{1}}{k_{2}}left[H_{2}right]left[I_{2}right] ) B. ( frac{d[H]}{d t}=frac{k_{1} k_{3}}{k_{2}} 2left[H_{2}right]left[I_{2}right] ) ( frac{d[H I]}{d t}=k_{2}left[H_{2}right]left[I_{2}right]^{2} ) D. None of the above |
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340 | For a ( 1^{s t} ) order reaction (gaseous) (costant ( vee, T) ) ( boldsymbol{a} boldsymbol{A} rightarrow(boldsymbol{b}-mathbf{1}) boldsymbol{B}+mathbf{1} boldsymbol{C}(text { with } mathbf{b}>mathbf{a}) ) the pressure of the system rose by ( 50left(frac{b}{a}-1right) % ) in a time of 10 min. The half life of the reaction is therefore: ( A cdot 10 ) min B. 20 min ( c . ) 30 min D. 40 min |
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341 | Question 4. The decomposition of dimethyl ether leads to the formation of CH4, H, and CO and the reaction rate is given by : Rate = k[CH3OCH313/2. The rate of reaction is followed by increase in pressure in a closed vessel, so the rate can be expressed in terms of the partial pressure of dimethyl ether i.e, Rate = k (PCH OCHZ). pressure is measured in bar and time in minutes, then what are the units of rate and rate constants? (i) In terms of pressure, units of rate = bar min Rate (ii) k= 32. Put the units of rate and PCH OCHą to find the units (PCH OCH ) of k. |
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342 | ( boldsymbol{A}+boldsymbol{B} longrightarrow boldsymbol{C} ; boldsymbol{Delta} boldsymbol{H}=+boldsymbol{6} boldsymbol{0} boldsymbol{K} boldsymbol{J} / boldsymbol{m o l} ) ( boldsymbol{E}_{boldsymbol{a} t} ) is ( 150 mathrm{kj} . ) What is the activation energy for the backward reation? A . 210 k. B. 105kJ c. 90 k D. 145kJ |
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343 | When sugar is stirred with a spoon in a glass of water, more sugar is dissolved and faster. Why? A. Spoon acts as a catalyst B. On stirring, temperature increases c. stirring increases the rate of interaction D. spoon increases the attraction between the molecules of water and sugar |
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344 | Answer the following questions: 1. Define instantaneous rate of reaction. 2. Explain pseudo first-order reaction with suitable example. |
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345 | Write the rate law for -Reaction is zero order in ( A ) and second order in ( B ). |
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346 | In the following reaction, how is the rate of appearance of ( B r_{2} ) related to the rate of disappearance of the ( B r^{-} ? ) ( boldsymbol{B} boldsymbol{r} boldsymbol{O}^{3-}(boldsymbol{a} boldsymbol{q})+boldsymbol{5} boldsymbol{B} boldsymbol{r}^{-}(boldsymbol{a} boldsymbol{q})+boldsymbol{6} boldsymbol{H}^{+} rightarrow ) ( mathbf{3} boldsymbol{B} boldsymbol{r}_{2}(boldsymbol{l})+boldsymbol{3} boldsymbol{H}_{2} boldsymbol{O}(boldsymbol{l}) ) A ( cdot frac{left.d B r_{2}right]}{d t}=-frac{dleft[B r^{-}right]}{d t} ) B. ( frac{dleft[B r_{2}right]}{d t}=+frac{3}{5} frac{dleft[B r^{-}right]}{d t} ) C. ( frac{left.d B r_{2}right]}{d t}=-frac{3}{5} frac{d B r-1}{d t} ) D. ( frac{dleft[B r_{2}right]}{d t}=-frac{5}{3} frac{dleft[B r^{-}right]}{d t} ) |
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347 | Explain, with the help of potential energy diagram, effect of temperature on the rate of reaction. |
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348 | The time required for a first-order reaction for ( 99 % ) completion is ( x ) times for the time required for ( 90 % ) completion. ( boldsymbol{x} ) is: |
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349 | For the reaction, ( boldsymbol{A}_{2}+boldsymbol{B}+boldsymbol{C} rightarrow boldsymbol{A} boldsymbol{C}+ ) ( A B, ) it is found that tripling the concentration of ( A_{2} ) triples the rate, doubling the concentration of C doubles the rate and doubling the concentration of B has no effect. (a) What is the rate law? (b) Why the change in concentration of B has no effect? |
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350 | The rate constants of a reaction at ( 500 K ) and ( 700 K ) are ( 0.02 s^{-1} ) and ( 0.07 s^{-1} ) respectively. Calculate the values of ( boldsymbol{E} boldsymbol{a} ) and ( boldsymbol{A} ) : |
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351 | A compound ( A ) dissociate by two parallel first order paths at certain temperature ( boldsymbol{A}(boldsymbol{g}) stackrel{boldsymbol{k}_{1}left(min ^{-1}right)}{longrightarrow} boldsymbol{2} boldsymbol{B}(boldsymbol{g}) boldsymbol{k}_{1}=boldsymbol{6} . boldsymbol{9} boldsymbol{3} times ) ( 10^{-3} min ^{-1} ) ( boldsymbol{A}(boldsymbol{g}) stackrel{boldsymbol{k}_{2}left(min ^{-1}right)}{longrightarrow} boldsymbol{C}(boldsymbol{g}) boldsymbol{k}_{2}=boldsymbol{6} . boldsymbol{9} boldsymbol{3} times ) ( 10^{-3} min ^{-1} ) The reaction started with 1 mole of pure ( A^{prime} ) in 1 litre closed container with initial pressure 2 atm. What is the pressure (in atm) developed in container after 50 minutes from start of experiment? A . 1.25 в. 0.75 c. 1.50 D. 2.50 |
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352 | Which of the following options does not show instantaneous rate of reaction at ( 40^{t h} ) second? A ( frac{V_{5}-V_{2}}{50-30} ) 3. ( frac{V_{4}-V_{2}}{50-30} ) ( c cdot frac{V_{3}-V_{2}}{40-30} ) D. ( frac{V_{3}-V_{1}}{40-20} ) |
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353 | Question 14. Why is the probability of reaction with moleculartity higher than three very rare? |
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354 | If ( A rightarrow ) products is a first order reaction then, write the integrated law equation. |
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355 | Define order of reaction. | 12 |
356 | Activation energy of a chemical reaction can be determined by temperature B. determining the rate constants at two temperatures c. determining probability of collision D. using catalyst |
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357 | The rate of formation of ( S O_{3} ) in the following reaction ( 2 S O_{2}+O_{2} rightarrow 2 S O_{3} ) is ( 10 g ) sec ( ^{-1} ). The rate of disappearance of ( boldsymbol{O}_{2} ) will be: A. ( 5 g ) sec ( ^{-1} ) B. ( 100 g ) sec ( ^{-1} ) ( mathrm{c} .20 mathrm{g} ) sec D. ( 2 g ) sec ( ^{-1} ) |
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358 | The reaction ( boldsymbol{A}(boldsymbol{g}) longrightarrow boldsymbol{B}(boldsymbol{g})+boldsymbol{2} boldsymbol{C}(boldsymbol{g}) ) is a first order reaction with rate constant ( 2.772 times 10^{-3} s^{-1} . ) Starting with 0.1 mole of ( A ) in 2 litre vessel, find the concentration of ( A ) after 250 sec when the reaction is allowed to take place at constant pressure at ( 300 K ? ) ( mathbf{A} cdot 0.0125 M ) В. 0.025 М c. ( 0.05 M ) D. none of these |
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359 | In milk, at ( 37^{circ} mathrm{C} ), lactobacillus acidophilus is a generation time of about 75 minutes. Calculate the population relative to the initial value at 30,60,75,90 and 150 minutes. |
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360 | Which of the following are examples of pseudo-unimolecular reactions? This question has multiple correct options ( mathbf{A} cdot C H_{3} C O_{2} C_{2} H_{5}+H_{2} O stackrel{H^{+}}{longrightarrow} C H_{3} C O_{2} H+C_{2} H_{5} O H ) ( mathbf{B} cdot C_{12} H_{22} O_{11}+H_{2} O stackrel{H^{+}}{rightarrow} C_{6} H_{12} O_{6}(g l u c o s e)+C_{6} H_{12} O_{6} ) (fructose) ( mathbf{c} cdot C H_{3} C O C l+H_{2} O rightarrow C H_{3} C O_{2} H+H C l ) ( mathrm{D} cdot mathrm{CH}_{3} mathrm{CO}_{2} mathrm{C}_{2} mathrm{H}_{5}+mathrm{H}_{2} mathrm{O} stackrel{mathrm{OH}^{-}}{longrightarrow} mathrm{CH}_{3} mathrm{CO}_{2} mathrm{H}+mathrm{C}_{2} mathrm{H}_{5} mathrm{OH} ) |
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361 | Write the difference between order and molecularity of a reaction. |
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362 | Collision diameter is least in case of: A ( . H_{2} ) в. ( H e ) ( c cdot C O_{2} ) D. ( N_{2} ) |
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363 | A first-order reaction which is ( 30 % ) complete in 30 minutes has a half-life period of: A .24 .2 min B. 58.2 min c. 102.2 min D. 120.2 min |
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364 | Consider the reaction, ( 2 N_{2} O_{5} rightarrow ) ( 4 N O_{2}+O_{2} ) In the reaction ( N O_{2} ) is being formed at the rate of 0.0125 mol ( L^{-1} s^{-1} . ) What is the rate of reaction at this time? A ( cdot 0.0018 ) mol ( L^{-1} s^{-1} ) B. 0.0031 mol ( L^{-1} s^{-1} ) c. 0.0041 mol ( L^{-1} s^{-1} ) D. 0.050 mol ( L^{-1} s^{-1} ) |
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365 | What is the name given to energy which must be provided in order for a chemical change to occur? A. Gibbs free energy B. Activation energy c. Potential energy D. Bond energy E. Kinetic energy |
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366 | Q. 43 The reaction between H, (q) and 0,(a) is highly feasible yet au gases to stand at room temperature in the same vessel does not lead to the formation of water. Explain. pornture but at high |
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367 | The unit ( m o l L^{-1} s^{-1} ) is meant for the rate constant of the reaction having the order: A. 0 B. 2 ( c cdot 1 ) D. |
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368 | The total pressure after 200 seconds, if the initial pressure is 0.1 atm is A. 0.154 atm B. 0.248 atm c. 0.174 atm D. 0.114 atm |
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369 | The correct matching is: ( mathbf{A} cdot|-a,|-b,||-c, mid V-d ) ( B cdot|-b,||-a,|||-d, mid V-c ) C. ( mid-d,|-c,| I-b, I V-a ) ( D cdot|-b,||-c,|||-d, mid V-a ) |
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370 | In case of unimolecular reaction, the time required for ( 99.9 % ) of the reaction to take place is ( x ) times that required for half of the reaction. The value of ( x ) is |
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371 | 0.47 Why does the rate of any reaction generally decreases during the course of the reaction? to reaction |
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372 | The rate of reaction between two reactants ( A ) and ( B ) decreases by a factor of 4 if the concentration of reactant B is doubled. The order of this reaction with respect to reactant B is: |
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373 | For a first order reaction with rate constant ( k ) and initial concentration a the half-life period is given by: This question has multiple correct options A ( cdot frac{ln 2}{k} ) B. ( frac{1}{k} ) c. ( frac{0.693}{k} ) D. ( frac{2.303}{k} log 2 ) |
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374 | Write notes on consecutive reactions with an example. |
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375 | What will be the half-life of the first order reaction for which the value of rate constant is ( 200 s^{-1} ? ) A . ( 3.46 times 10^{-2} s ) B. ( 3.46 times 10^{-3} s ) c. ( 4.26 times 10^{-2} s ) D. ( 4.26 times 10^{-3} s ) |
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376 | The rate law for the reaction below is given by the expression ( boldsymbol{k}[boldsymbol{A}][boldsymbol{B}] ) ( A+B rightarrow ) Product If the concentration of ( B ) is increased from 0.1 to 0.3 mole, keeping the value of ( A ) at 0.1 mole, the rate constant will be: ( mathbf{A} cdot 3 k ) B. ( 9 k ) c. ( k / 3 ) D. |
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377 | If the rate of reaction increases by 27 times, when temperature is increased by ( 30 mathrm{K}, ) then temperature coefficient of the reaction is: ( A cdot 3 ) B. 2 ( c ) D. 2.5 |
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378 | Question 19. Why molecularity is applicable only for elementary reactions and order is applicable for elementary as well as complex reactions? |
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379 | Question 8. For a certain reaction large fraction of molecules has energy more than the threshold energy, yet the rate of reaction is very slow, why? catti from the onera considerations the colliding |
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380 | Question 15. Why does the rate of any reaction generally decreases during the course of the reaction? |
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381 | Which of the following is not correct reason for the substantially lower rate of reaction than the collision frequency? A. All the collisions do not attain threshold energy level B. The activated complex formed is short lived c. All the collisions do not have proper orientation D. Effective collision are lesser in number than all collisions |
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382 | Q. 18 Which of the following statement is not correct for the catalyst? (a) It catalyses the forward and backward reactions to the same extent (b) It alters AG of the reaction (c) It is a substance that does not change the equilibrium constant of a reaction (d) It provides an alternate mechanism by reducing activation energy between reactants and products |
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383 | :he rate constant of reaction ( 2 A+ ) ( B longrightarrow C ) is ( 2.57 times 10^{-5} ) it ( m o l e^{-1} s e c^{-1} ) after 10 sec. ( 2.65 times 10^{-5} ) it mole ( ^{-1} ) sec ( ^{-1} ) after 20 sec. and ( 2.55 times ) ( 10^{-5} ) it mole( ^{-1} )sec( ^{-1} ) after 30 sec. The order of the reaction is: A. B. 1 ( c cdot 2 ) D. 3 |
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384 | The rate reaction is measured either by an increase in the amount of products or by the decrease in the amount of reactants per unit interval of time. A. True B. False |
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385 | Write condition under which a bimolecular reaction is kinetically first order. Given an example of such a reaction. (Given: ( log 2=0.3010, log 3= ) ( mathbf{0 . 4 7 7 1}, log mathbf{5}=mathbf{0 . 6 9 9 0}) ) |
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386 | Reaction, ( 3 C l O^{-} rightarrow C l O_{3}^{-}+2 C l ) occurs in following two steps. I. ( C l O^{-}+C l O^{-} stackrel{K_{1}}{longrightarrow} C l O_{2}^{-}+C l^{-} ) (Slow step) ( mathrm{Il.} mathrm{ClO}_{2}^{+} mathrm{ClO}^{-} stackrel{k_{2}}{longrightarrow} mathrm{ClO}_{3}^{-}+mathrm{Cl}^{-} ) (Fast step) Then, the rate of given reaction is: ( mathbf{A} cdot k_{1}left[C l O^{-}right] ) B. ( k_{1}left[C l O^{-}right]^{2} ) c. ( k_{2}left[C l O_{2}^{-}right]left[C l O^{-}right] ) D. ( k_{2}left[C l O^{-}right]^{3} ) |
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387 | For a first order gas phase reaction: ( boldsymbol{A}_{(boldsymbol{g})} rightarrow boldsymbol{2} boldsymbol{B}_{(boldsymbol{g})}+boldsymbol{C}_{(boldsymbol{g})} ) ( P_{0} ) be initial pressure of ( A ) and ( P, ) the total pressure at time ‘ ( t^{prime} . ) Integrated rate equation is: A ( cdot frac{2.303}{t} log left(frac{P_{0}}{P_{0}-P_{t}}right) ) B. ( frac{2.303}{t} log left(frac{2 P_{0}}{3 P_{0}-P_{t}}right) ) c. ( frac{2.303}{t} log left(frac{P_{0}}{2 P_{0}-P_{t}}right) ) D ( cdot frac{2.303}{t} log left(frac{2 P_{0}}{2 P_{0}-P_{t}}right) ) |
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388 | Which among the following plots are liner (a-x) is the concentration of the reactant remaining after time, t? (1):- (a-x) vs t, for a first order reaction (2)( :-(a-x) ) vs ( t, ) for a zero order reaction (3):- (a-x) vs t, for a second order reaction (4):-1/ (a-x) vs t, for a second order reaction A. 1 and 2 B. 1 and 3 ( c cdot 2 ) and 3 D. 2 and 4 |
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389 | Consider the reaction ( boldsymbol{A}_{2}+boldsymbol{B} rightarrow ) products. If the concentration of ( A_{2} ) and B are halved, the rate of the reaction decreases by a factor of 8. If the concentration of ( A ) is increased by a factor of ( 2.5, ) the rate increases by the factor of ( 2.5 . ) What is the order of the reaction? Write the rate law. |
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390 | What will be the order of reaction for a chemical change having ( log t_{1 / 2} ) vs log a? (where a = initial concentration of reactant; ( t_{1 / 2}= ) half-life? A. zero order B. First order c. second order D. None of these |
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391 | For the reaction ( R rightarrow P ). the concentration ofa reactant changes frotn ( 0.03 M ) to ( 0.02 M ) in 25 minutes. Calculate the average rate of reaction using units of time both in minutes and seconds. |
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392 | In the reaction ( 2 N O_{(g)}+2 H_{2_{(g)}} rightarrow ) ( N_{2_{(g)}}+2 H_{2} O, ) if initial concentration of hydrogen is kept constant and the concentration of NO is doubled, the rate of reaction increases by 4 times. This shows that rate is directly proportional to A. catalyst B. concentration of nitric oxide c. concentration of Hydrogen D. concentration of water |
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393 | Statement 1: Many chemical reactions slow down with lowering temperature. Statement 2: The energy barrier for the formation of products decreases with decreasing temperature. A. Statement 1 and Statement 2 are correct and Statement 2 is the correct explanation of Statement 1 B. Both the Statement 1 and Statement 2 are correct, but Statement 2 is NOT the correct explanation of Statement 1. c. statement 1 is correct, but statement 2 is not correct D. Statement 1 is not correct, but Statement 2 is correct |
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394 | Question 6. A reaction is second order with respect to a reactant. How is the rate of reaction affected if the concentration of the reaction is (i) doubled (ii) reduced to half? (For Il order reaction), rate = k[A]. Find the rate expression when concentration is doubled or reduced to half and compare it with the normal rate. |
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395 | The unit of rate and rate constant are same for a: A. zero order reaction B. First order reaction c. second order reaction D. Third order reaction |
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396 | What are the units of rate constant of a pseudo unimolecular reaction? |
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397 | A reaction takes place in three steps. The rate constants are ( k_{1}, k_{2} ) and ( k_{3} ) The over all rate constant ( boldsymbol{k}=frac{boldsymbol{k}_{1} boldsymbol{k}_{3}}{boldsymbol{k}_{2}} . ) If (energy of activation) ( E_{1}, E_{2} ) and ( E_{3} ) The overall energy of activation is: A. 40 B. 30 c. 400 D. 60 |
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398 | Catalytic decomposition of nitrous oxide by gold at ( 900^{circ} mathrm{C} ) at an initial pressure of ( 200 mathrm{mm}, ) was ( 50 % ) in 53 minutes and ( 73 % ) in 100 minutes. Velocity constant of the reaction is: [Note: assume decomposition as the first order. A ( .1 .308 times 10^{-2} ) В. ( 2.317 times 10^{-2} ) c. ( 3.208 times 10^{-3} ) D. none of these |
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399 | The rate of simple reaction ( 2 N O+ ) ( O_{2} longrightarrow 2 N O_{2}, ) when the volume of the reaction vessel is doubled. |
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400 | The chemical reaction, ( 2 O_{3} rightarrow 3 O_{2} ) proceeds as follows; ( O_{3} rightleftharpoons O_{2}+O dots(text { Fast }) ) ( boldsymbol{O}+boldsymbol{O}_{3} rightarrow boldsymbol{2} boldsymbol{O}_{2} ldots(text { Slow }) ) The rate law expression should be: A ( cdot r=Kleft[O_{3}right]^{2} ) B . ( r=Kleft[O_{3}right]^{2}left[O_{2}right]^{-1} ) ( mathbf{c} cdot r=Kleft[O_{3}right]left[O_{2}right] ) D. unpredictable |
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401 | If the half-life period of a first-order reaction is 138.6 min, then the value of decay constant for the reaction will be: A ( .5 mathrm{min}^{-1} ) B. 0.5 min ( ^{-1} ) c. 0.05 min ( ^{-1} ) D. ( 0.005 min ^{-1} ) |
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402 | 27 According to Maxwell, Boltzmann distribution of energy,………. (a) the fraction of molecules with most probable kinetic energy decreases at higher temperatures (b) the fraction of molecules with most probable kinetic energy increases at higher temperatures (c) most probable kinetic energy increases at higher temperatures (d) most probable kinetic energy decreases at higher temperatures |
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403 | ( boldsymbol{H}_{2}+boldsymbol{I}_{2} rightarrow 2 boldsymbol{H} boldsymbol{I} ) What is the ( K_{e q} ) for the reaction shown above if ( boldsymbol{H}_{2}=mathbf{1} ) atm, ( boldsymbol{I}_{2}=mathbf{2} ) atm and ( boldsymbol{H} boldsymbol{I}=boldsymbol{3} ) atm? A . 0.33 в. 3 ( c cdot 0.22 ) D. 0.67 E . 4.5 |
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404 | Which of the following statements does not apply to a given rate law corresponding to a specific reaction? A. As the temperature changes, the rate of reaction changes. B. As the reaction rate changes, the rate constant does not change c. As the concentration of the reactants changes, the unit of the rate constant changes. D. As the concentration of the reactants change, the rate of reaction changes |
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405 | For ( 2 A+B+C rightarrow 2 D ), determine the rate law for the reaction based on the following data. ( begin{array}{lllll}operatorname{Exp} & {[boldsymbol{A}]} & {[boldsymbol{B}]} & {[boldsymbol{C}]} & begin{array}{l}text { Rate of } \ text { disappearance } \ (mathrm{M} / mathrm{s})end{array} \ & & & & \ 1 & 0.1 & 0.1 & 0.1 & X \ 2 & 0.2 & 0.2 & 0.1 & 8 X \ & & & & \ 3 & 0.2 & 0.1 & 0.1 & 4 X \ & & & & \ 4 & 0.2 & 0.1 & 0.2 & 32 Xend{array} ) A ( . ) Rate ( =k[A]^{2}[B][C] ) B . Rate( =k[A]^{2}[B][C]^{3} ) c. Rate( =k[A]^{2}[B]^{3}[C] ) D. ( operatorname{Rate}=k[A]^{2}[B]^{2}[C]^{3} ) |
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406 | The rate of a reaction increases four fold when the concentration of reactant is increased 16 times. If the rate of reaction is ( 4 times 10^{-6} ) mol ( L^{-1} s^{-1} ) when the concentration of the reactant is ( 4 times 10^{-4} ) mol ( L^{-1} . ) The rate constant of the reaction will be: B. ( 1 times 10^{-2} mathrm{s}^{-1} ) C . ( 2 times 10^{-4} mathrm{mol}^{-1 / 2} mathrm{L}^{1 / 2} mathrm{s}^{-1} ) D. 25 mol-1 L min ( ^{-1} ) |
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407 | An organic compound undergoes firstorder decomposition. The time taken for its decomposition to ( 1 / 8 ) and ( 1 / 10 ) of its initial concentration are ( t_{1 / 8} ) and ( t_{1 / 10} ) respectively. The value of ( frac{left[t_{1 / 8]}right.}{left[t_{1 / 10}right]} times 10 ) is ( ? ) ( left(operatorname{take} log _{10} 2=0.3right) ) |
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408 | Units of average rate of reaction is: ( A cdot sec ^{-1} ) B. mole sec ( ^{-1} ) c. mole ( mathrm{dm}^{-3} mathrm{sec}^{-1} ) D. unitless |
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409 | In a zero order reaction, the time taken to reduce the concentration of reactant from ( 50 % ) to ( 25 % ) is 30 minutes.What is the time required to reduce the concentration from 25% to 12.5%? |
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410 | Figure depicts the charge in conc. of species ( x & y ) for reaction ( 2 x rightarrow y, ) as a function of time the point of inter section of two curves represents? ( A cdot t_{1 / 2} ) В ( cdot t_{1 / 3} ) ( c cdot t_{1 / 4} ) ( mathbf{D} cdot t_{2} ) |
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411 | In a pseudo first order acid catalysed hydrolysis of ester in water the following results were obtained: ( t / s ) 0.30 60 [ester]/M 0.550 .31 0.17 ( quad 0.085 ) Which of the following is/are correct for the given reaction? This question has multiple correct options A. The average rate of reaction between time interval 30 to 60 seconds is ( 4.67 times 10^{-3} ) mol ( L^{-1} s^{-1} ) B. Order of reaction is 2. c. Pseudo first order rate constant for the acid catalysed hydrolysis of ester is ( 1.92 times 10^{-2} s^{-1} ) D. All are correct. |
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412 | Assertion For a first order reaction, ( t_{1 / 2} ) is independent of the initial concentration of reactants. Reason For a first order reaction, ( t_{1 / 2} ) is thrice the ( t_{7 / 8} ) A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is correct but Reason is incorrect D. Both Assertion and Reason are incorrect |
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413 | Assertion Two different reactions can never have same rate of reaction. Reason Rate of reaction always depends only on frequency of collision and Arrhenius factor. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion C. Assertion is correct but Reason is incorrect D. Both Assertion and Reason are incorrect |
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414 | At ( 27^{circ} mathrm{C} ) it was observed in the hydrogenation of a reaction, the pressure of ( boldsymbol{H}_{2}(boldsymbol{g}) ) decreases from 10 ( operatorname{atm} operatorname{to} 2 operatorname{atm} ) is 10 min. The rate of the reaction is ( 3 times 10^{-x} ) Mmin ( ^{-1} ). Find the value of ( x ) ( left[text { Given } R=0.08 L operatorname{atm} K^{-1} m o l^{-1}right] ) |
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415 | 11. If with different initial concentrations of ( mathbf{A} ) and ( mathrm{B} ), the initial rate of reaction were determined graphically in four experiments. Find the rate of reaction ( (r ) ) ( A ) ( r=k[A]^{2}[B]^{2} ) ( mathbf{B} cdot r=k[A]^{2}[B] ) ( mathbf{c} cdot r=k[A][B]^{2} ) D. ( r=k[A][B ) |
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416 | The rate law for a reaction between substances ( A ) and ( B ) is given by Rate( = ) ( boldsymbol{k}[boldsymbol{A}]^{n}[boldsymbol{B}]^{m} ) On doubling the concentration of ( A ) and halving the concentration of ( mathrm{B} ), the ratio of the new rate to the earlier rate of reaction will be: ( A cdot m+n ) B. n-m ( c cdot 2^{n-m} ) D. ( frac{1}{2^{m+n}} ) |
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417 | Which statements describe the condition(s) required for a successful formation of a product in a reaction? A. The collision must involve a sufficient amount of energy, provided from the motion of the particles, to overcome the activation energy B. The relative orientation of the particles has little or no effect on the formation of the product C. The relative orientation of the particles has an effect only if the kinetic energy of the particles is below some minimum value D. The relative orientation of the particles must allow for formation of the new bonds in the product E. The energy of the incoming particles must be above a certain minimum value and the relative orientation of the particles must allow for formation of new bonds in the product |
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418 | In the Arrhenius equation for a certain reaction, the value of ( A ) and ( E ) (energy of activation) are ( 4 times 10^{-13} mathrm{sec}^{-1} ) and ( 98.6 k J ) mol( ^{-1} ) respectively. If the reaction is of the first order, the temperature at which its half-life period will be 10 minutes in ( K ) will be ( x ) then find the value of ( x / 6 ) to the nearest integer. |
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419 | The volume of dry ( N_{2} O ) produced at this point measured at STP is L) |
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420 | Chemical kinetics, a branch of physical chemistry, deals with: A. heat changes in a reaction B. physical changes in a reaction c. rate of reactions D. structure of molecules |
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421 | What are pseudounimolecular reactions? Explain the help of suitable example. |
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422 | Question 3. How can you determine the rate law for the following reaction? 2NO(g) + O2(g) → 2NO2() function of |
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423 | If a first order reaction is completed to the extent of ( 75 % ) and ( 50 % ) in time interval, ( t_{1} ) and ( t_{2}, ) what is the ratio ( t_{1} ) ( t_{2} ? ) A . ( ln 2 ) B. ( frac{ln (3 / 4)}{ln 2} ) ( c cdot 2 ) D. ( 1 / 2 ) |
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424 | In the reaction, ( boldsymbol{A}+boldsymbol{B} longrightarrow boldsymbol{C}+boldsymbol{D}, ) the rate ( left(frac{d x}{d t}right) ) when plotted against time ( t^{prime} ) gives a straight line parallel to time axis and at some time ( ^{prime} t^{prime}, frac{d x}{d t}=k . ) The order and rate of reaction will be: A. ( 1, k+1 ) в. ( 0, k ) ( mathbf{c} cdot(1+k), 1 ) D. ( k, k+1 ) |
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425 | For a reaction ( : A+B rightarrow ) Products, the rate of the reaction at various concentrations are given below: Expt [А] ( quad ) [В] rate (mol Io ( left.d m^{-3} s^{-1}right) ) ( begin{array}{lll}text { 0.2 } & text { 0.2 } & text { 2. }end{array} ) ( 0.2 quad 0.4 ) ( begin{array}{ll}0.4 & 36end{array} ) The rate law for the above reaction is : A ( cdot r=K[A]^{2}[B] ) B . ( r=K[A][B]^{2} ) c . ( r=K[A]^{3}[B] ) D . ( r=K[A]^{2}[B]^{2} ) |
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426 | Which one of the following statements for order of reaction is not correct? A. Order can be determined experimentally B. Order of reaction is equal to sum of powers of concentration terms in differential rate law c. It is not affected by the stoichiometric coefficient of the reactants D. Order cannot be fractional |
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427 | Consider a gaseous reaction, the rate of which is given by ( k[A][B] . ) The volume of the reaction vessel containing these gases is suddenly reduced to ( 1 / 4^{t h} ) of the initial volume. The rate of the reaction as compared with original rate is: A ( cdot frac{1}{16} ) times B. 16 times c. ( frac{1}{8} ) times D. 8 times |
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428 | Given that the rate of disappearance of bromine is ( -3.5 times 10^{-4} M / s ) for the following reaction: ( boldsymbol{H}_{2(g)}+boldsymbol{B} boldsymbol{r}_{2(g)} rightarrow boldsymbol{2} boldsymbol{H} boldsymbol{B} boldsymbol{r}_{(a q)} ) What is the rate of formation for ( boldsymbol{H} boldsymbol{B r} ) ? A. ( -7.0 times 10^{-4} mathrm{M} / mathrm{s} ) В. ( -3.5 times 10^{-4} mathrm{M} / mathrm{s} ) c. ( 3.5 times 10^{-4} M / s ) D. ( 7.0 times 10^{-4} mathrm{M} / mathrm{s} ) |
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429 | The rate of reaction that does not involve gases, is not dependent on: A. pressure B. temperature c. concentration D. catalyst |
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430 | For the reaction system: ( mathbf{2} N O(g)+O_{2}(g) rightarrow 2 N O_{2}(g) ) volume is suddenly reduced to half its value by increasing the pressure on it. If the reaction is of first order with respect to ( O_{2} ) and second order with repeat to ( mathrm{NO} ) the rate of reaction will: A. increase to eight times of its initial value B. increase to four times of its initial value c. decrease to one-fourth of its initial value D. decrease to one-eighth of its initial value |
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431 | The rate constant of a first order reaction is 0.0693 min( ^{-1} ) Time (in minutes) required for reducing an initial concentration of 20 mol ( l i t^{-1} ) to 2.5 mol ( l i t^{-1} ) is : A . 40 B. 30 c. 20 D. 10 |
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432 | The rate of chemical reaction depends on the nature of reactants because: A. the number of bonds broken in the reactant molecules and the number of bonds formed in product molecules changes B. some of the reactants are solids at the room temperature C. some of the reactants are coloured D. some of rectants are liquid at room temperature |
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433 | The rate law for a single step reaction ( mathbf{2} boldsymbol{A}+boldsymbol{B} rightarrow boldsymbol{P} ) is ( boldsymbol{k}[boldsymbol{A}][boldsymbol{B}] ) A. True B. False |
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434 | ( boldsymbol{A} rightleftharpoons boldsymbol{B}+boldsymbol{C} ) Time ( t ) Total pressure of ( (boldsymbol{B}+boldsymbol{C}) quad boldsymbol{P}_{2} ) Find equilibrium constant ( k ) A ( cdot k=frac{1}{t} ln frac{P_{3}}{2left(P_{3}-P_{2}right)} ) в. ( _{k=frac{1}{t} l n frac{P_{2}}{2left(P_{3}-P_{2}right)}} ) c. ( k=frac{1}{t} ln frac{P_{3}}{2left(P_{3}+P_{2}right)} ) D. None of these |
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435 | A reaction which is of first order w.r.t reactant ( A, ) has a rate constant 6 ( boldsymbol{m} boldsymbol{i n}^{-1} . ) If we start with ( [boldsymbol{A}]=mathbf{0 . 5 m o l} ) ( boldsymbol{L}^{-1}, ) when would ( [boldsymbol{A}] ) reach the value of ( 0.05 m o l L^{-1} ? ) ( mathbf{A} cdot 0.384 mathrm{min} ) B. 0.15 min c. 3 min D. 3.84 min |
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436 | For a homogeneous gaseous reaction, ( boldsymbol{A} longrightarrow boldsymbol{B}+boldsymbol{C}+boldsymbol{D}, ) the initial pressure was ( P_{0} ) while pressure at time ( t ) was ( P ) Derive an expression for rate constant ( K ) in terms of ( P_{0}, P ) and ( t ) [Assume first-order reaction] |
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437 | For a reaction ( 2 N O(g)+C l_{2}(g) rightarrow ) ( 2 N O C l(g), ) when concentration of ( C l_{2} ) is doubled the rate of reaction becomes two-times of the original. When the concentration of ( N O ) is doubled the rate becomes four times. What is the order of the reaction? A . 1 B. 2 ( c .3 ) D. 4 |
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438 | Derive an expression for integrated rate law for a zero order reaction. | 12 |
439 | Mathematical expression for ( t_{1 / 4} ) i.e. when ( (1 / 4)^{t h} ) reaction is over following first order kinetics can be given by: A ( cdot t_{1 / 4}=frac{2.303}{K} log 4 ) B cdot ( t_{1 / 4}=frac{2.303}{K} log 1 / 4 ) C ( cdot t_{1 / 4}=frac{2.303}{K} log 2 ) D ( cdot t_{1 / 4}=frac{2.303}{K} log frac{4}{3} ) |
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440 | A reaction ( A+B rightarrow C ) is second order with respect to ( A ) and independent of ( B ) The rate expression for the reaction is: A. ( r a t e=K[A][B] ) B . rate ( =K[A]^{2}[B] ) c. ( r a t e=K[A]^{2}[B]^{2} ) D. rate ( =K[A]^{2} ) |
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441 | Which of the following statement is incorrect about order of reaction? A. Order of reaction is determined experimentally B. It is the sum of power of concentration terms in the rate law expression c. It does not necessarily depend on stoichiometric coefficients D. Order of the reaction can not have fractional value |
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442 | ( A ) and ( B ) are two different chemical species undergoing 1st order decomposition with half lives equal to 5 ( sec ) and 7.5 sec respectively. If the initial concentration of ( A ) and ( B ) are in the ratio ( 3: 2 . ) Calculate ( frac{C_{A_{1}}}{C_{B_{1}}} ) after three half lives of ( A ). Report your answer after multiplying it with 100 |
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443 | In the decomposition of oxalic acid following data were obtained. [ begin{array}{lcc} text { Time (second) } & 0 & 300 \ text { Volume of } K M n O_{4} & 22.0 & 17.0 end{array} ] used in ( mathrm{mL} ) If reaction obeys 1 st order kinetics then determine the rate constant K and half- life period: A ( cdot 8.43 times 10^{-4} ) sec ( , 13.7 ) minute B . ( 86 times 10^{-4} ) sec ( , 134.3 ) minute c. ( 8.6 times 10^{-5} ) sec ( , 1.343 ) minute D. None of these |
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444 | ( boldsymbol{C C l}_{3} boldsymbol{C H O}+boldsymbol{N O} longrightarrow boldsymbol{C H C l}_{3}+ ) ( N O+C O ) The rate of the reaction above is equal to rate ( =boldsymbol{k}left[boldsymbol{C C l}_{3} boldsymbol{C H O}right][boldsymbol{N O}] ) If the concentration is expressed in mol ( mathrm{L}^{-1}, ) find the unit of ( k ? ) A ( cdot mathrm{Lmol}^{-1} mathrm{s}^{-1} ) B. molL ( ^{-1} mathrm{s}^{-1} ) c. ( L^{2} ) mol ( ^{-2} s^{-1} ) D. s ( ^{-1} ) |
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445 | Thermal decomposition of a compound is of first order. If ( 50 % ) sample of the compound is decomposed in 120 minute, how long will it take for ( 90 % ) of the compound to decompose? |
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446 | Write the two steps involved in the mechanism of the enzyme-catalyzed reaction. |
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447 | Unit of the rate of reaction is: A. concentration B. concentration ( times ) time c. concentration D. concentration ( ^{2} ) |
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448 | For hypothetical chemical reaction ( mathbf{A} rightarrow ) I it is found that the reaction is third order in A. What happens to the rate of reaction when the concentration of ( A ) is doubled? A. Rate increases by a factor 2 B. Rate decreases by a factor 3 c. Rate increases by a factor 8 D. Rate remains unaffected |
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449 | In a first order reaction, ( 1010 % ) is complete Calculate:The half life of the reaction: |
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450 | Q. 39 For a reaction A+B Products, the rate law is-Race Can the reaction be an elementary reaction? Explain. to react is referred to the rate law is –Rate = k[A] [B]3/2 Ans. During an alam |
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451 | For a reaction scheme ( boldsymbol{A} stackrel{boldsymbol{k}_{1}}{longrightarrow} boldsymbol{B} stackrel{boldsymbol{k}_{2}}{longrightarrow} boldsymbol{C}, ) if the rate of formation of ( B ) is set to be zero then the concetration of ( B ) is given by: ( ^{A} cdotleft(frac{k_{1}}{k_{2}}right)[A] ) B . ( left(k_{1}+k_{2}right)[A] ) c. ( k_{1} k_{2}[A] ) D. ( left(k_{1}-k_{2}right)[A] ) |
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452 | In a first order reaction with time the concentration of the reactant decreases: A. Linearly B. Exponentially c. No change D. None of these |
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453 | The energy of activation for the reaction is: A. ( E_{a}=2.9311 times 10^{5} ) В. ( E_{a}=2.3933 times 10^{5} ) C . ( E_{a}=2.1398 times 10^{5} ) D. None of these |
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454 | The value of rate constant of a pseudo first order reaction A. depends on the concentration of reactants present in small amount B. depends on the concentration of reactants present in excess C. is independent of the concentration of reactants D. depends only on temperature |
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455 | ( N_{2} O_{5} ) decomposes according to equation: [ mathbf{2} N_{2} boldsymbol{O}_{mathbf{5}} rightarrow mathbf{4} boldsymbol{N} boldsymbol{O}_{mathbf{2}}+boldsymbol{O}_{mathbf{2}} ] What does ( frac{boldsymbol{d}left[boldsymbol{O}_{2}right]}{boldsymbol{d} boldsymbol{t}} ) denote? |
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456 | If certain decomposition reaction found to obey equation in term of partial pressure (P) of reactant : ( frac{boldsymbol{a}-boldsymbol{p}^{2}}{boldsymbol{p}^{2}}=boldsymbol{b k t} ) what is order of reaction if ( a, b ) and ( k ) are constant (t represents time)? ( A cdot 3 ) B. 6 ( c cdot 2 ) ( D ) |
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457 | For a reaction ( boldsymbol{A} stackrel{boldsymbol{K}_{1}}{longrightarrow} boldsymbol{B} stackrel{boldsymbol{K}_{2}}{longrightarrow} boldsymbol{C} . ) If the reaction are of ( 1^{s t} ) order then ( frac{boldsymbol{d}[boldsymbol{B}]}{boldsymbol{d} boldsymbol{t}} ) is equal to: A . ( -k[B] ) B. ( +k_{1}[A] ) ( mathbf{c} cdot k_{1}[A]-k_{2}[B] ) D. ( k_{1}[A]+k_{2}[B] ) |
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458 | The speed of a reaction is determined by: A. rate of reaction B. temperature of reaction c. nature of reactant D. flow of reactants |
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459 | The half-period T for the decomposition of ammonia on tungsten wire was measured for different initial pressures ( P ) of ammonia at ( 25^{circ} mathrm{C} ). Then: ( P(m m ) ( begin{array}{llll}11 & 21 & 48 & 73end{array} ) Hg) ( mathrm{T}(mathrm{sec}) ) 48 92 [ text { 210 } quad 320 ] This question has multiple correct options A. Zero order reaction B. First order reaction C. Rate constant for reaction is 0.114 mol lit ( ^{-1} ) sec ( ^{-1} ) D. Rate constant for reaction is 1.14 seconds |
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460 | For which order reaction, the unit of rate constant is ( operatorname{tim} e^{-1} ? ) A. Zero order B. First order c. Second order D. Third order |
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461 | Q. 20 Consider the reaction A B . The concentration of both the reactants and the products varies exponentially with time. Which of the following figures correctly describes the change in concentration of reactants and products with time? [B] [B] Concentration- Concentration- Time- Time- Concentration- Concentration- Time- Time |
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462 | Question 5. A first order reaction has a rate constant 1.15 x108 How long will 5 g of this reactant take to reduce to 3 g? For Ist order reaction : * = 2.908 109 so calculatet by using t = 2.308 109 |
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463 | Which of the following reaction is a fast reaction at laboratory temperature? A . Reaction between ( K M n O_{4} ) and oxalic acid B. Reaction between ( K M n O_{4} ) and mohr’s salt c. Hydrolysis of ethyl acetate D. Thermal decomposition of ( N_{2} O_{5} ) |
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464 | ( 2 A rightarrow ) Product, follows the first order kinetics. If the half life period of the reaction at ( [boldsymbol{A}]_{text {initial}}=mathbf{0 . 2} ) mole lit( ^{-1} ) is 20 min. then the value of rate constant would be:- ( A cdot 4 sec ) B. 20 sec c. 4 litmol( ^{-1} min ^{-1} ) D. None of these |
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465 | The rate for a first order reaction is ( 0.6932 times 10^{-2} ) mol litre ( ^{-1} min ^{-1} ) and the initial concentration of the reactant is ( 1 mathrm{M}, t_{1 / 2} ) is equal to: B. 100 minutes c. ( 0.693 times 10^{-3} ) minute D. 6.932 minutes |
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466 | Assertion In rate law, unlike in the expression for equilibrium constants, the exponents for concentrations do not necessarily match the stoichiometric coefficients. Reason t is the mechanism and not the balanced chemical equation for the overall change that governs the reaction rate A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion C. Assertion is correct but Reason is incorrect D. Both Assertion and Reason are incorrect |
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467 | For a chemical reaction, ( boldsymbol{m} boldsymbol{A} longrightarrow boldsymbol{x} boldsymbol{B} ) the rate law is ( r=k[A]^{2} . ) If the concentration of ( A ) is doubled, the reaction rate will be : A. doubled B. quadrupled c. increases by 8 times D. unchanged |
12 |
468 | The reaction, ( boldsymbol{X} longrightarrow boldsymbol{Y}(text { Product }) ) follows first order kinetics. In 40 minutes, the concentration of ( boldsymbol{X} ) changes from ( 0.1 ~ M ) to ( 0.025 M ), then the rate of reaction when concentration of ( boldsymbol{X} ) is ( mathbf{0 . 0 1} boldsymbol{M} ) is: A ( cdot 1.73 times 10^{-4} mathrm{M} / mathrm{min} ) B . 3.47 ( times 10^{-5} mathrm{M} / mathrm{min} ) c. ( 3.47 times 10^{-4} mathrm{M} / mathrm{min} ) D. ( 1.73 times 10^{-5} mathrm{M} / mathrm{min} ) |
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469 | In a reaction of acidified hydrogen peroxide with potassium iodide, the concentration of iodine formed rises from 0 to ( 10^{-5} ) mol ( d m^{-3} ) in 10 seconds. What is the rate of reaction? A ( cdot 10^{-6} ) mold ( m^{-3} s^{-1} ) B ( cdot 10^{6} ) mol ( d m^{-3} s^{-1} ) c. ( 10^{-5} ) mold ( m^{-3} s^{-1} ) D. ( 10^{4} ) mol ( d m^{-3} s^{-1} ) |
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470 | The units of rate of reaction and the rate constant are identical for a A. fraction-order reaction B. zero-order reaction c. first-order reaction D. second-order reaction |
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471 | Decomposition of ( boldsymbol{H}_{2} boldsymbol{O}_{2} ) is a first order reaction. A 16 volume solution of ( boldsymbol{H}_{2} boldsymbol{O}_{2} ) of half life 30 min is present at start. When will the solution become one volume? A. After 120 min B. After 90 min c. After 60 min D. After 150 min |
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472 | A reaction has an activation energy of ( 209 k J . m o l^{-1} . ) The rate increases 10 fold when the temperature is increased from ( 27^{circ} mathrm{C} ) to ( X^{o} C . ) The temperature ( X ) is closest to.[Gas constant, ( boldsymbol{R}=mathbf{8 . 3 1 4} ) ( left.boldsymbol{J} cdot boldsymbol{m} boldsymbol{o} boldsymbol{l}^{-1} boldsymbol{K}^{-1}right] ) A . 35 B . 40 c. 30 D. 45 |
12 |
473 | The value of pre-expotential factor is : A . ( A=1.25 times 10^{18} s^{-1} ) B. ( A=1.95 times 10^{18} s^{-1} ) c. ( A=1.56 times 10^{18} s^{-1} ) D. None of these |
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474 | The half-life period of an 1st order reaction is 60 minutes. What percentage will be left over after 240 minutes? ( mathbf{A} cdot 6.25 % ) B. ( 4.25 % ) c. ( 5 % ) D. ( 6 % ) |
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475 | The study of chemical kinetics becomes highly complicate if there occurs: This question has multiple correct options A. reversible reaction B. side reaction c. surface reaction D. none of these |
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476 | For the chemical reaction ( 5 B r^{ominus}+ ) ( B r O_{3}^{ominus}+6 H^{oplus} rightarrow 3 B r_{2}+3 H_{2} O ) Rate ( =kleft[B r^{ominus}right]left[B r O_{3}^{ominus}right]left[H^{oplus}right]^{2} ) The molecularity and order of reaction with respect to ( left[B r^{ominus}right] ) is: A .5,1 в. 1,5 ( c .1,1 ) D. 6,2 |
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477 | What are effective collisions? This question has multiple correct options A. Collisions leading to the transformation of reactants to products B. formation of activated complex c. collison between two reactant to decrease the activation energy D. collison between two reactant to overcome activation energy barrier |
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478 | A first order reaction is ( 75 % ) completed in 100 minutes. How long time will it take for it’s ( 87.5 % ) completion? A. 125 min B. 150 min c. 175 min D. 200 min |
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479 | Ans.(b Q. 55 Match the items of Column I and Column II Column Column II A Diamond 1. Short interval of time B. Instantaneous rate 2 Ordinarily rate of conversion is imperceptible Average rate 3. Long duration of time Q.5 |
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480 | ( mathbf{4} boldsymbol{H}^{+}+boldsymbol{M} boldsymbol{n} boldsymbol{O}_{4}^{-}+boldsymbol{C}_{2} boldsymbol{O}_{4}^{2-} rightarrow boldsymbol{M} boldsymbol{n}^{2+}+ ) ( 2 C O_{2}+4 O H^{-} ) For the preceding reaction, which of the following statements is not always true based on the knowledge that oxalate reacts slowly at room temperature causing a fade in the purple colour due to the manganate ion? A. Using an acid-base catalyst will increase the overal rate of the reaction B. There are multiple steps in the reaction mechanism. c. The reaction is carried out at elevated temperatures to make the procedure practical in terms of time D. Use of a spectrophotometer and a Beer’s Law plot will help determine the rate for the overall reaction mechanism. |
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481 | A first order reaction takes 69.3 minutes for ( 50 % ) completion. How much time will be needed for ( 80 % ) completion? |
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482 | The term -dx/dt in the rate expression refers to: A. The concentration of the reactants B. Increase in the concentration of the reactants c. The instantaneous rate of the reaction D. The average rate of the reaction |
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483 | For the reaction ( A rightarrow B ) it has been found that the order of the reaction is zero with respect to A. Which of the following expressions correctly describes the reaction? A ( cdot K=frac{2.303}{t} log frac{left[A_{0}right]}{[A]} ) B ( cdotleft[A_{0}right]-[A]=K t ) ( mathbf{c} cdot_{t_{1 / 2}}=frac{0.693}{K} ) D. ( t_{1 / 2} propto frac{1}{left[A_{0}right]} ) |
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484 | Reactions having molecularity ( geq 2 ) and order of reaction ( =_{-1-} ) are known as pseudo unimolecular reactions. | 12 |
485 | ( boldsymbol{B r} boldsymbol{O}_{3}^{-}(boldsymbol{a q})+mathbf{5 B r}_{(a q)}^{-}+boldsymbol{6 H}^{+} rightarrow ) ( mathbf{3} boldsymbol{B r}_{2}(mathbf{1})+mathbf{3} boldsymbol{H}_{2} boldsymbol{O}_{(1)} ).The rate of apprearance of bromine ( left(B r_{2}right) ) is related to rate of disappearance of bromide ions as following: A ( cdot frac{dleft(B r_{2}right)}{d t}=-frac{5}{3} frac{dleft(B r^{-}right)}{d t} ) B. ( frac{dleft(B r_{2}right)}{d t}=frac{5}{3} frac{dleft(B r^{-}right)}{d t} ) C ( cdot frac{dleft(B r_{2}right)}{d t}=frac{3}{5} frac{d(B r)}{d t} ) D. ( frac{dleft(B r_{2}right)}{d t}=-frac{3}{5} frac{dleft(B r^{-}right)}{d t} ) |
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486 | For a general reaction ( boldsymbol{X} rightarrow boldsymbol{Y}, ) the plot of conc. of ( boldsymbol{X} ) vs time is given in the figure. What is the order of the reaction and what are the units of rate constant? A. zero, mol ( L^{-1} s^{-1} ) B. First, ( operatorname{mol} L^{-1} s^{-1} ) ( c . ) First, ( s^{-1} ) D. zero, L mol- ( s_{s}^{-} ) |
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487 | Change in concentration of product is 0.05 mole ( l^{-1} ) in 20 seconds. Average rate of reaction is A .0 .0025 moles ( s^{-1} ) B. 1 moles ( s^{-1} ) c. 0.05 moles ( s^{-1} ) D. none of these |
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488 | 2.58 Assertion (A) Order and molecularity are same. Reason (R) Order is determined experimentally and molecularity is the sum of the stoichiometric coefficient of rate determining elementary step. |
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489 | Identify the options in which increase in rate of reaction will be maximum: (1) ( E_{a}=40 ) Id/mole Temperature change 300 to ( 310 mathrm{K} ) (II) ( E_{a}=80 mathrm{kJ} / mathrm{mole} ) Temperature change 200 to ( 210 mathrm{K} ) (III) ( E_{a}=60 ) Id/mole Temperature change 400 to ( 410 mathrm{K} ) A . I B. ( c . ) ॥ D. All four will experience same change |
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490 | A study of chemical kinetics of the reaction ( mathbf{A}+mathbf{B} rightarrow ) products, gave the following data at ( 25^{circ} mathrm{C} ) Experiment ( [mathrm{A}] ) ( [mathrm{B}] ) [ frac{boldsymbol{d}[boldsymbol{P r o d u c t s}]}{boldsymbol{d t}} ] 1.0 0.15 ( 4.20 times 10^{-6} ) 2 ( begin{array}{lll}text { 2.0 } & text { 0.15 } & 8.40 times 10^{-6}end{array} ) 3 1.0 0.20 ( quad 5.60 times 10^{-6} ) Find: (1) The order of reaction with respect to ( mathbf{A} ) (2) The order of reaction with respect to B. (3) The rate law. |
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491 | Effective collisions are those in which molecules must: A. have energy equal to or greater than the threshold energy B. have proper orientation c. acquire the energy of activation D. all of the above |
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492 | If in the fermentation of sugar in an enzymatic solution that is ( 0.12 M ), the concentration of the sugar is reduced to ( 0.06 M ) in ( 10 h ) and ( 0.03 M ) in ( 20 h, ) what is the order of the reaction: ( A ) B. 2 ( c cdot 3 ) D. |
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493 | If the activation energies of the forward and backward reactions of a reversible reaction are ( boldsymbol{E}_{boldsymbol{a}}(boldsymbol{f}) ) and ( boldsymbol{E}_{boldsymbol{a}}(boldsymbol{b}) ) respectively. The ( Delta E ) of the reaction is A ( cdot E_{a}(F)-E_{a}(b) ) B . ( E_{a}(F)+E_{a}(b) ) ( mathbf{c} cdot E_{a}(F)=E_{a}(b) ) D. ( -E_{a}(F)+E_{a}(b) ) |
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494 | The activation energy for a hypothetical reaction, ( boldsymbol{A} longrightarrow ) Product, is ( 12.49 k c a l / ) mol. If the temperature is raised from ( 295 ~ K ) to ( 305 K ), the rate of reaction increases by: A . ( 60 % ) B. ( 100 % ) c. ( 50 % ) D. 20% |
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495 | Fastest rate of reaction will be when ( boldsymbol{R} ) is: ( mathbf{A} cdot C H_{3}- ) в. ( C H_{3}-C H_{2} ) c. ( C H_{3}-begin{array}{r}C H- \ \ C H_{3}end{array} ) ( begin{array}{l}text { D. } \ qquad C H_{3}-begin{aligned} & C H_{3} \ & C H end{aligned} \ & _{C H_{3}}end{array} ) |
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496 | In the following reaction, ( A rightarrow B ), rate constant is ( 1.2 times 10^{-2} M s^{-1} . ) What is the concentration of ( B ) after 10 min, if we start with ( 10 M ) of ( A ? ) A. 7.2 ( M ) B. 4.5 M ( c cdot 6.7 M ) D. 7.0 M |
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497 | Give a detailed account of the collision theory of reaction mils of Bimolecular gaseous reactions. |
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498 | ( 99 % ) of a first order reaction was completed in 32 min. When will ( 99.9 % ) of the reaction complete? A. 24 min B. 8 min c. 4 min D. 48 min |
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499 | Thermal decomposition of a compound is of first order. If 50 percent of a sample of compound is decomposed in 120 mins, how long will it take for 90 percent of compound to decompose? ( mathbf{A} cdot 299 mathrm{mins} ) B. 399 mins. c. 99 mins. D. 9.9 mins. |
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500 | In a first order reaction the concentration of reactant decreases from 800 mol ( / d m^{3} ) to ( 50 m o l / d m^{3} ) in ( 2 times 10^{4} ) sec. The rate constant of reaction in ( sec ^{-1} ) is: A ( cdot 2 times 10^{4} ) B. ( 3.415 times 10^{-5} ) c. ( 1.386 times 10^{-4} ) D. None of these |
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501 | In a plot of ( log k ) vs ( 1 / T, ) the slope is A ( cdot frac{-E_{a}}{2.303} ) в. ( frac{E_{a}}{2.303 R} ) c. ( frac{E_{a}}{2.303} ) D. ( frac{-E_{a}}{2.303 R} ) |
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502 | The energies of activation for ( boldsymbol{A}_{mathbf{2}}+ ) ( B_{2} rightleftharpoons 2 A B ) are ( 180 k J ) mol ( ^{-1} ) forward and ( 200 k J ) mol ( ^{-1} ) reverse reactions respectively. The presence of catalyst lowers the activation energies of both (forward and reverse) reactions ( left(boldsymbol{A}_{2}+right. ) ( B_{2} rightleftharpoons 2 A B ) by ( 100 k J ) mol ( ^{-1} . ) The magnitude of enthalpy change of the reaction in the presence of catalyst will be ( left(text { in } mathbf{k} text { J } boldsymbol{m} boldsymbol{o} boldsymbol{l}^{-1}right) ) A. 300 B. 120 c. 20 D. -20 |
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503 | The decomposition of ( N H_{3} ) on finely divided platinum follows the rate expression, Rate ( =frac{boldsymbol{k}_{mathbf{1}}left[boldsymbol{N} boldsymbol{H}_{3}right]}{mathbf{1}+boldsymbol{k}_{2}left[boldsymbol{N} boldsymbol{H}_{3}right]} ) It is a first order reaction when concentration of ( boldsymbol{N} boldsymbol{H}_{3} ) is: A. very low B. very high c. moderate D. never |
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504 | The rate constant for a first order reaction is ( 7.0 times 10^{-4} s^{-1} . ) If initial concentration of reactant is ( 0.080 M ) what is the half life of reaction? ( mathbf{A} cdot 990 s ) B . ( 79.2 s ) c. 12375 s D. ( 10.10 times 10^{-4} mathrm{s} ) |
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505 | 0.60 Assertion (A) All collision of reactant molecules lead to product formation. Reason (R) Only those collisions in which molecules have correct orientation and sufficient kinetic energy lead to compound formation. |
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506 | A first order reaction is ( 60 % ) complete in 20 min. How long will the reaction take to be ( 84 % ) complete? A. 60 min B. 40 min c. 76 min D. 54 min |
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507 | What do you understand by rate of a reaction? Explain why the rate of a reaction cannot be measured by dividing the total amount of reactant consumed by the time taken. | 12 |
508 | In a first order reaction, the concentration of the reactant decreases from ( 0.8 ~ M ) to 0.4 in 15 minutes. The time taken for the concentration to change from ( 0.1 mathrm{M} ) to ( 0.025 mathrm{M} ) is: A. 30 min B. 40 min ( c .35 ) min D. 25 min |
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509 | 0.36 For which type of reactions, order and molecularity have the same value? | 12 |
510 | The conversion of vinyl allyl ether to pent-4-enol follows a certain kinetics. The following plot is obtained for such a reaction. A . zer B. ( c ) 2 |
12 |
511 | The thermal decomposition of HCOOH is a first-order reaction with a rate constant of ( 2.4 times 10^{-3} s^{-1} ) at certain temperature. How long will it take for three-fourths of the initial quantity of ( H C O O H ) to decompose? A. 578 sec B. 225 sec ( c .436 mathrm{sec} ) D. 57.8 sec |
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512 | The decomposition of ( N H_{3} ) on platinum surface is zero order. What are the rate of production of ( N_{2} ) and ( H_{2} ) in mole.lit( ^{-1} cdot sec ^{-1} ) if ( K=2.5 times ) ( 10^{-4} ) mole.lit ( ^{-1} . ) sec ( ^{-1} ? ) ( begin{array}{ll}text { A } cdot 3.75 times 10^{-4}, & 1.25 times 10^{-4}end{array} ) B. ( 1.25 times 10^{-4}, quad 3.75 times 10^{-4} ) C . ( 2.5 times 10^{-4}, quad 7.5 times 10^{-4} ) D. ( 1.25 times 10^{4}, quad 3.75 times 10^{-4} ) |
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513 | ( mathbf{2} N_{2} O_{5}(g) rightarrow 4 N O_{2}(g)+O_{2}(g) ) What is the ratio of the rate of decomposition of ( N_{2} O_{5} ) to rate of formation of ( N O_{2} ? ) ( A cdot 1: 2 ) B. 2: ( c cdot 1: 4 ) ( D cdot 4: ) |
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514 | At ( 373 mathrm{k} ) the half-life period for the thermal decomposition of ( N_{2} O_{5} ) is 4.6 sec and is independent of the initial pressure of ( N_{2} O_{5} ). Calculate the specific rate constant of this temperature. ( mathbf{A} cdot K=0.1507 s^{-1} ) В. ( K=0.3014 s^{-1} ) C . ( K=0.1507 s^{-2} ) D. ( K=0.3014 s^{-2} ) |
12 |
515 | Q Type your question which the first step is slowest and the last step is fastest? (Assume that reaction is exothermic) ( A ) B. ( c ) None of these |
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516 | The initial pressure of the reactant at ( 500 K, ) in the reaction ( C a C O_{3}=C a O+ ) ( C O_{2} ) is ( 200 m m . ) After ( 20 m ) ins the pressure is reduced to ( 150 mathrm{mm} ). Find the average rate of the reaction? A . ( 0.33 times 10^{-6} ) molL ( ^{-1} ) sec ( ^{-1} ) B . ( 2.33 times 10^{-6} ) molL ( ^{-1} ) sec ( ^{-1} ) ( mathbf{c} cdot 1.33 times 10^{-6} mathrm{molL}^{-1} mathrm{sec}^{-1} ) D. ( 3.33 times 10^{-6} ) molL ( ^{-1} ) sec ( ^{-1} ) |
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517 | For the gas phase decomposition ( boldsymbol{A} rightarrow ) ( 2 B, ) the rate constant is ( 6.93 times 10^{-3} ) ( min ^{-1} ) at ( 300 mathrm{K} . ) The percentage of ( mathrm{A} ) remaining at the end of 300 minutes is : A . 75 B. 50 ( c cdot 25 ) D. 12.5 |
12 |
518 | Explain why? Rate of reaction is change in concentration in a given time interval The change in concentration is (final concentration – initial concentration). As the reaction progresses the change in concentration of reactants decreases and that of products increases. D C gets a negative sign in case of reactants and positive sign in case of products. |
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519 | How can the rate of the chemical reaction, namely, decomposition of hydrogen peroxide be increased? |
12 |
520 | The oxidation of iodide ion by perdisulphate ion is described as follows : ( boldsymbol{I}^{Theta}+boldsymbol{S}_{2} boldsymbol{O}_{8}^{2-} rightarrow boldsymbol{I}_{3}^{Theta}+boldsymbol{S} boldsymbol{O}_{4}^{2-} ) If the rate disappearance of ( S_{2} O_{8}^{2-} ) ions is ( 1.5 times 10^{-3} M s^{-1}, ) the rate of formation of ( boldsymbol{S O}_{4}^{2-} ) ions is: ( mathbf{A} cdot 3.0 times 10^{-3} M s^{-1} ) B . ( 2.5 times 10^{-3} M s^{-1} ) C ( .2 .75 times 10^{-3} mathrm{M} mathrm{s}^{-1} ) D. None of these |
12 |
521 | The rate law for the dimerisation of ( N O_{2} ) is ( frac{-dleft[N O_{2}right]}{d t}=kleft[N O_{2}right]^{2} ) Which of the following changes will change the value of the specific rate constant ( (mathrm{k}) ? ) A. Doubling the total pressure on the system B. Doubling the temperature c. Both A and B D. None of these |
12 |
522 | For the non-equilibrium process, ( boldsymbol{A}+ ) ( B rightarrow ) Products, the rate is first order with respect to ( A ) and second-order with respect to ( B ). If 1.0 mole each of ( A ) and ( B ) are introduced into a 1 -litre vessel and the initial rate was ( 1.0 times 10^{-2} ) mol/litre-sec. The rate (in mol litre ( ^{-1} ) sec ( ^{-1} ) ) when half of the reactants have been used: A ( cdot 1.2 times 10^{-3} ) В. ( 1.2 times 10^{-2} ) c. ( 2.5 times 10^{-4} ) D. none of these |
12 |
523 | Question 18. Why can’t molecularity of any reaction be equal to zero? | 12 |
524 | According to collision theory, write name of two factors which increases the rate of reaction as temperature increase. |
12 |
525 | 18. Starting with a sample of pure “Cu, – of it decays into Zn in 15 min. The corresponding half-life is (a) 5 min (b) 75 min (c) 10 min (d) 15 min (AIEEE 2005) |
12 |
526 | Express the rate for the following reaction in terms of concentration of reactants and products. ( boldsymbol{H}_{2}(boldsymbol{g})+boldsymbol{I}_{2}(boldsymbol{g}) rightarrow boldsymbol{2} boldsymbol{H} boldsymbol{I}(boldsymbol{g}) ) |
12 |
527 | ( 2 A+3 B rightarrow 4 C ) if the rate of decomposition of ( A ) is ( 2.5 times 10^{-4} ) then Calculate the rate of decomposition of B and rate of formation of ‘C’. |
12 |
528 | The rate constant of a first order reaction at ( 25^{circ} mathrm{C} ) is ( 0.24 s^{-1} . ) If the energy of activation of the reaction is ( 88 k J ) mol ( ^{-1}, ) at what temperature would this reaction have rate constant of ( 4 times 0^{-2} s^{-1} ? ) |
12 |
529 | Which of the following are true for the first order reaction? This question has multiple correct options A ( cdot t_{3 / 4}=2 t_{1 / 2} ) B . ( t_{15 / 16}=4 t_{1 / 2} ) C ( cdot t_{15 / 16}=3 t_{3 / 4} ) D. ( t_{7 / 8}=2 t_{3 / 4} ) |
12 |
530 | The initial rate of zero-order reaction of the gaseous equation ( A(g) rightarrow 2 B(g) ) is ( 10^{-2} mathrm{M} min ^{-1} ) if the initial concentration of ( A ) is 0.1 M. What would be a concentration of ( B ) after 60 seconds? ( mathbf{A} cdot 0.09 M ) в. ( 0.01 M ) c. ( 0.02 M ) D. ( 0.03 M ) |
12 |
531 | In the case of a zero-order reaction, the ratio of time required for ( 75 % ) completion to ( 50 % ) completion is: A ( . ln 2 ) B . 2 c. 1.5 D. none |
12 |
532 | The half life period of a first order reaction is 10 minutes. The time required for the concentration of the reactant to change from ( 0.08 M ) to 0.02 ( M ) is: A . 10 min B. 20 min c. 30 min D. 40 min |
12 |
533 | A drop of a solution (volume ( =0.05 m l ) ) contains ( 6 times 10^{-7} ) mole of ( H^{+} ) If the rate of disappearance of ( boldsymbol{H}^{+} ) is ( 6.0 times 10^{5} ) mol ( L^{-1} s^{-1} ) How long will it take for the ( H^{+} ) in the drop to disappear? A ( .8 .0 times 10^{-8} mathrm{s} ) B . ( 2.0 times 10^{-8} ) s c. ( 6.0 times 10^{-6} mathrm{s} ) D. ( 2.0 times 10^{-2} mathrm{s} ) |
12 |
534 | Question 4. For which type of reactions, order and molecularity have the same value? |
12 |
535 | A reaction of first – order completed ( 90 % ) in 90 minutes, hence, it is completed ( 50 % ) in approximately: A. 50 min в. 54 min c. 27 min D. 62 min |
12 |
536 | Activation energy of a reaction is: A. the energy released during the reaction. B. the energy evolved when activated complex is formed. C . additional amount of energy needed by the reactants to overcome the potential barrier of reaction. D. the energy needed to form one mole of the product. |
12 |
537 | The rate of chemical reaction: (except zero order) This question has multiple correct options A. decreases from moment to moment B. remains constant throughout C. depends upon the order of reaction D. none of the above |
12 |
538 | O .35 How can you determine the rate law of the following reaction? 2NO(g) + O2(g) → 2NO, (g) |
12 |
539 | Use the following data for the gas phase decomposition of hydrogen iodide to find the average rate of the reaction in moles HI/litre over the first 2 hours. t, hours ( quad ) o ( quad 2 quad ) 4 [ begin{array}{llll} text { [HI], M } & 1 & 0.5 & 0.33 end{array} ] A. 0.25 B. 0.35 ( c cdot 0.5 ) D. 2 |
12 |
540 | Question 1. From the rate expression for the following reactions determine their order of reaction and the dimensions of the rate constants. (1) 3NO(g) → N20(9); Rate = k [NOF (ii) H2O2 (aq) + 31 (aq) + 2H+ 2H2O(l) + 13; Rate = k [H202][1] (iii) CH3CHO(g) → CH. (g) + CO(g): Rate = k[CH3CHO]3/2 (iv) C2H5Cl(g) → CH4 (8) + HCl(g); Rate = k [CH,Cl] (a) If rate = k[A] [B]y, then order of reaction = x + y; so find order from rate law. (b) k = Rate/[AY [B]Y = concentration/time x (concentration)”, calculate units of k in the similar manner. |
12 |
541 | The spontaneous decomposition of radio nuclei is a first order rate process.U-238 disintegrates with the emission of ( alpha ) -particles and has a half- life of ( 4.5 times 10^{9} ) years. If at time ( t=0,1 ) mole of U-238 is present, what will be the number of nuclei left after 1 billion years? A ( cdot 5.16 times 10^{23} ) 3 B . ( 5.16 times 10^{20} ) ( mathbf{c} cdot 5.16 times 10^{19} ) D. None of these |
12 |
542 | For a first order reaction, to obtain a positive slope, we need to plot: ( {[A] text { is the concentration of reactant } A} ) ( mathbf{A} cdot log _{10}[A] ) vs ( t ) B. ( -log _{e}[A] ) vs t ( mathbf{C} cdot log _{10}[A] ) vs ( log t ) D. ( [A] ) vs t |
12 |
543 | The rate of a certain reaction at different times are as follows: ( begin{array}{ll}text { Time } & text { rate }left(text { mole } l i t^{-1} sec ^{-1}right) \ text {1) } 0 & text { a) } 2.8 times 10^{-2}end{array} ) “) 10 ( quad ) b) ( 2.78 times 10^{-2} ) -2 A ( begin{array}{ll}text { III) } 20 & text { с) } 2.81 times 10^{-2}end{array} ) -2 ( begin{array}{ll}text { ।V) } 30 & text { d) } 2.79 times 10^{-2}end{array} ) ( j ) ( ^{2} ) The correct matching is: A. zero order B. first order c. second order D. third order |
12 |
544 | Assertion If the order of reaction is zero, then degree of dissociation will be independent of initial concentration. Reason The degree of dissociation of zero order reaction is given by ( boldsymbol{alpha}=frac{boldsymbol{k} boldsymbol{t}}{boldsymbol{c}_{0}} ) A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is correct but Reason is incorrect D. Assertion is incorrect but Reason is correct |
12 |
545 | One gram of ( ^{226} ) Ra has an activity of nearly ( 1 C ) i. The half life of ( ^{226} R a ) is A. 1582 yrs B. 12.5 hrs c. 140 days D. ( 4.5 times 10^{9} ) yrs |
12 |
546 | For the reaction, ( 2 N O+C l_{2} longrightarrow ) ( 2 N O C l, ) the following mechanism has been proposed: ( N O+C l_{2} rightleftharpoons N O C l_{2} ) ( N O C l_{2}+N O longrightarrow 2 N O C l ) (slow) The rate law for the reaction is: A ( cdot ) Rate ( =k[N O]^{2}left[C l_{2}right] ) B・Rate ( =k[N O]left[C l_{2}right]^{2} ) c. Rate ( =kleft[N O C l_{2}right] ) D・Rate ( =k[N O C l]^{2} ) |
12 |
547 | For a firt order reaction ( boldsymbol{A} rightarrow boldsymbol{P}, ) the temperature (T) dependent rate constant (k) was found to follow the equation ( log k=-(2000) frac{1}{T}+6.0 . ) The pre-exponential factor A and the activation energy ( E_{a}, ) respectively, are? A . ( 1.0 times 10^{6} s^{-1} ) and ( 9.2 k J ) mol ( ^{-1} ) B. ( 6.0^{-1} ) and ( 16.6 k J ) mol ( ^{-1} ) C . ( 1.0 times 10^{6} s^{-1} ) and ( 16.6 k J ) mol ( ^{-1} ) D. ( 1.0 times 10^{6} s^{-1} ) and ( 38.3 k J ) mol( ^{-1} ) |
12 |
548 | Which increases average kinetic energy? A. An increase in the reaction concentration B. An increase in temperature c. A decrease in pressure D. Catalysis E ( . p H ) |
12 |
549 | Which of the following terms in the Arrhenius equation, ( boldsymbol{k}=boldsymbol{A} boldsymbol{e}^{-boldsymbol{E}_{a} /(boldsymbol{R} boldsymbol{T})}, ) is not labeled correctly? ( mathbf{A} cdot E_{A} ) is the activation energy of the reaction B. T refers to temperature C. ( k ) refers to the rate constant of the reaction D. R refers to electrical resistance of the reaction mixture E. e is Euler’s number, the natural base of the exponential function with a value of approximately 2.718281828 |
12 |
550 | A certain reaction is of first order. After 540 seconds, ( 32.5 % ) of the reactant remains. (a) Calculate the rate constant. (b) How long would it require for ( 25 % ) of the reactant to be decomposed? |
12 |
551 | For the reaction ( boldsymbol{A}+boldsymbol{B} rightarrow boldsymbol{C}+boldsymbol{D} ) doubling the concentration of both the reactants increases the reaction rate 8 times an ddoubling the concentration of only ( B ) simply dubles the reaction rate. Find the rate law for the above equation. |
12 |
552 | 0.4 Consider figure and mark the correct option. Activated complex Energy – Products Reactants Reaction coordinate (a) Activation energy of forward reaction is E; + Eand product is less stable than reactant (b) Activation energy of forward reaction is E; + E, and product is more stable than reactant (c) Activation energy of both forward and backward reaction is E, + E, and reactant is more stable than product (d) Activation energy of backward reaction is E, and product is more stable than reactant |
12 |
553 | The half life of a first order reaction is 1.7 hours. How long will it take for ( 20 % ) of the reactant to disappear? |
12 |
554 | If the unit of rate constant of a reaction is ( m o l^{-1} L S^{-1} ) then mention its order. |
12 |
555 | In the reaction, ( 2 N_{2} O_{5} rightarrow 4 N O_{2}+O_{2} ) initial pressure is 500 atm and rate constant ( k ) is ( 3.38 times 10^{-5} s e c^{-1} . ) After 10 minutes the final pressure of ( N_{2} O_{5} ) is: A. 490 atm B. 250 atm c. 480 atm D. 420 atm |
12 |
556 | Reaction ( boldsymbol{A}+boldsymbol{B} longrightarrow boldsymbol{C}+boldsymbol{D} ) follows rate ( operatorname{law}, boldsymbol{r}=boldsymbol{k}[boldsymbol{A}]^{1 / 2}[boldsymbol{B}]^{1 / 2} ) starting with ( mathbf{1} boldsymbol{M} ) of ( A ) and ( B ) each. What is the time taken for concentration of ( boldsymbol{A} ) become ( mathbf{0 . 1} boldsymbol{M} ) ? ( left[text { Given } 2.303 times 10^{-2} s e c^{-1}right] ) ( mathbf{A} cdot 10 sec ) B. 100sec c. 1000 sec D. 434 sec |
12 |
557 | If ( H_{2} O ) is taken in large excess, the order of the reaction will be: ( mathbf{A} cdot mathbf{1} ) B. ( c cdot 3 ) D. 2 |
12 |
558 | The branch of chemistry which deals with the study of chemical reaction rate is known as: A. thermochemistry B. electrochemistry c. chemical kinetics D. none of these |
12 |
559 | For a reaction ( boldsymbol{A}_{(g)} rightarrow boldsymbol{B}_{(g)}+boldsymbol{C}_{(g)}, ) the rate constant for the reaction is ( 3 x ) ( 10^{-3} M^{-} ) min ( ^{-1} . ) At what concentration of ( A ) will at the rate of reaction be ( 2 x ) ( 10^{-3} mathrm{M} mathrm{min} ) A. 1 м в. 0.52 М c. 0.82 М D. ( frac{2}{3} ) N |
12 |
560 | Rate constant for a particular reaction is ( 3 times 10^{-6} ) mole ( left.^{-2}right|^{2} s^{-1} . ) The rate of reaction for only single reactant is found to be ( 2.4 times 10^{2} ) mole ( I^{-1} s^{-1} . ) The equilibrium concentration of the reactant could be: A ( cdot 0.8 times 10^{4} ) B . ( 2 times 10^{2} ) c. ( 0.8 times 10^{2} ) D. ( 2 times 10^{text { }} ) |
12 |
561 | The half life period of a first order reaction is 20 minutes. The time required for the concentration of the reactant to change from ( 0.16 M ) to ( mathbf{0 . 0 2} boldsymbol{M} ) is: ( mathbf{A} .80 ) minutes B. 60 minutes c. 40 minutes D. 20 minutes |
12 |
562 | Question 30. The rate of a reaction quadruples when the temperature changes from 293 K to 313 K. Calculate the energy of activation of the reaction assuming that it does not change with temperature. |
12 |
563 | Consider the chemical reaction: ( N_{2}(g)+3 H_{2}(g) rightarrow 2 N H_{3}(g) ) The rate of this reaction can be expressed; in terms of time and of concentration of ( N_{2}(g), H_{2}(g) N H_{3}(g) ) Identify the correct relationship amongst the rate expressions. A ( cdot operatorname{Rate}=-frac{dleft[N_{2}right]}{d t}=-frac{1}{3} frac{dleft[H_{2}right]}{d t}=+frac{1}{2} frac{dleft[N H_{3}right]}{d t} ) B. ( operatorname{Rate}=-frac{dleft[N_{2}right]}{d t}=-frac{3 dleft[H_{2}right]}{d t}=frac{2 dleft[N H_{3}right]}{d t} ) c. ( operatorname{Rate}=-frac{dleft[N_{2}right]}{d t}=-frac{1}{3} frac{dleft[H_{2}right]}{d t}=frac{dleft[N H_{3}right]}{d t} ) D. ( operatorname{Rate}=-frac{dleft[N_{2}right]}{d t}=frac{dleft[H_{2}right]}{d t}=frac{dleft[N H_{3}right]}{d t} ) |
12 |
564 | Determine the average life ( U^{238} ) having ( t_{1 / 2}=140 ) days. |
12 |
565 | Why reactions of higher order are unknown? |
12 |
566 | ( 60 % ) of the first-order reaction was completed in 60 min. The time taken for reactants to decompose to half of their original amount will be: ( mathbf{A} cdot approx 30 min ) в. ( approx 60 ) min ( mathbf{c} . approx 90 min ) ( mathbf{D} cdot approx 45 min ) |
12 |
567 | Consider the graph given in figure. When of the following options does not show instantaneous rate of reaction at ( 40 s: ) ( A ) B. ( frac{V_{4}-V_{2}}{50-300} ) ( c cdot frac{V_{3}-V_{2}}{40-30_{2}} ) D. ( frac{V_{3}-V_{1}}{40-200} ) |
12 |
568 | Which of the following statements regarding molecularity of the reaction is correct? A. Molecularity relates to mechanism of reaction B. It cannot be negative or fractional c. Molecularity of a complex reaction has two(or) more steps and each individual step has its own molecularity D. All are correct |
12 |
569 | The rate of the reaction, ( boldsymbol{A}+boldsymbol{B}+boldsymbol{C} longrightarrow ) Products, is given by, ( -frac{boldsymbol{d}[boldsymbol{A}]}{boldsymbol{d} t}= ) ( boldsymbol{k}[boldsymbol{A}]^{1 / 2}[boldsymbol{B}]^{1 / 3}[boldsymbol{C}]^{1 / 4} ) The order of the reaction is: A ( cdot frac{1}{2} ) в. ( frac{13}{12} ) c. 1 D. 2 |
12 |
570 | The rate equation for the reaction ( boldsymbol{A}+ ) ( 2 B rightarrow ) Products is given as rate( = ) ( boldsymbol{K}[boldsymbol{A}][boldsymbol{B}]^{2} . ) If the volume of the vessel is decreased to half of the initial volume, then the reaction rate bears the following relation to the original rate as: A. ( 1 / 2 ) times B. 2 times c. 4 times D. 8 times |
12 |
571 | Q. 40 For a certain reaction large fraction of molecules has e the threshold energy, yet the rate of reaction is very slow the colliding molecules Large fraction of molecules has energy more than e of reaction is very slow. Why? |
12 |
572 | For the reaction ( 2 N H_{3} rightarrow N_{2}+3 H_{2} ) a curve is plotted between ( left[N H_{3}right] ) is time as shown Calculate the (A) Rate of disappearance between 5 and 10 sec (B) Rate of disappearance between 10 and 20 sec |
12 |
573 | A reaction is represented as ( 2 A+B mapsto ) ( 2 C+3 D . ) The concentration of ( C ) at 10 s is 4 moles ( l^{-1} ). The concentration of ( C ) at 20 seconds is 5.2 moles ( l^{-1} . ) The rate of reaction of ( mathrm{B} ) in the same time interval could be : A. -0.12 mole ( l^{-1} S^{-1} ) B. -0.6 mole ( l^{-1} S^{-1} ) c. -0.06 mole ( l^{-1} S^{-1} ) D. -1.2 mole l” ( S^{-1} ) |
12 |
574 | For the reaction, ( 2 N O+C l_{2} longrightarrow ) ( 2 N O C l ) at ( 300 K ) following data are obtained ( begin{array}{ll}underset{mathrm{No}}{operatorname{Exp}} & frac{text {InitialConcentration}}{[mathrm{NO}]left[mathrm{CI}_{2}right]}end{array} ) 1 ( begin{array}{ll}text { 0. } 0.010 & text { 0.010 }end{array} ) 2 ( begin{array}{cc}0.010 & 0.020end{array} ) 3 ( begin{array}{cc}0.020 & 0.020end{array} ) Write rate law for the reaction. What is the order of the reaction? Also calculate the specific rate constant. |
12 |
575 | For the reaction ( 2 A+B rightarrow C+ ) ( D,-frac{boldsymbol{d}[boldsymbol{A}]}{boldsymbol{d} boldsymbol{t}}=boldsymbol{k}[boldsymbol{A}]^{2}[boldsymbol{B}] . ) The expression for ( frac{-boldsymbol{d}[boldsymbol{B}]}{boldsymbol{d} boldsymbol{t}} ) will be: ( mathbf{A} cdot K[A]^{2}[B] ) B . ( 1 / 2 K[A]^{2}[B] ) ( mathbf{c} cdot K[A]^{2}[2 B] ) D. ( K[2 A]^{2}[B] ) |
12 |
576 | Assertion The order of reaction is equal to molecularity of simple reactions: Reason Molecularity of the reaction can not be fractional: A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is correct but Reason is incorrect D. Both Assertion and Reason are incorrect |
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577 | An aqueous solution of ( C H_{3} C O O H ) has a ( mathrm{pH}=3 ) and acid dissociation constant of ( C H_{3} C O O H ) is ( 10^{-5} . ) What will be the concentration of acid taken initially? A. ( 0.1 mathrm{M} ) B. 0.11 М c. 0.09 М D. 0.101 М |
12 |
578 | Question 12. Why does the rate of a reaction increase with rise in temperature? |
12 |
579 | Graph between log k and 1/T [k is rate constant ( left(s^{-1}right) ) and ( T ) the temperature (K) ( ] ) is a straight line with ( 0 X=5, theta= ) ( tan ^{-1}(1 / 2.303) . ) Hence ( -E_{a} ) will be : A . 2.303 2 cal B. 2/2.303 cal c. 2 cal D. None |
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580 | Which of the following statements is not correct about order of a reaction? A. The order of a reaction can be a fractional number B. Order of a reaction is experimentally determined quantity C. The order of a reaction is always equal to the sum of the stoichiometric coefficients of reactants in the balanced chemical equation for a reaction D. The order of a reaction is the sum of the powers of molar concentration of the reactants in the rate law expression |
12 |
581 | The rate of the chemical reaction doubles for an increase of ( 10 mathrm{K} ) in absolute temperature from ( 298 mathrm{K} ) Calculate ( boldsymbol{E}_{boldsymbol{a}} ) |
12 |
582 | All first order reactions are unimolecular. A. True B. False |
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583 | ( boldsymbol{A} rightarrow boldsymbol{B} ) ( boldsymbol{K}_{boldsymbol{A}}=mathbf{1 0}^{mathbf{1 5}} boldsymbol{e}^{mathbf{2 0 0 0} / boldsymbol{T}} ) ( boldsymbol{C} rightarrow boldsymbol{D} quad boldsymbol{K}_{boldsymbol{C}}=mathbf{1 0}^{14} boldsymbol{e}^{mathbf{1 0 0 0} / boldsymbol{T}} ) Temperature ( mathrm{T} mathrm{K} ) at which ( left(boldsymbol{K}_{boldsymbol{A}}=boldsymbol{K}_{boldsymbol{C}}right) ) is : ( A cdot 1000 K ) B. 2000 K D. (1000 / 2.303) K |
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584 | Question 2. For the reaction, 2A + B A B the rate = k[A][B] with k=2.0 x10 mol-LS-I. Calculate the initial rate of reaction when 1A1=0.1 mol L-.[B]= 0.2 mol L-. Calculate the rate of reaction after [4] is reduced to 0.06 mol L. (0) Calculate rate by using rate = k [A] [B] as you know k. [A and[B]. (ii) In second case, calculate the amount of B left with the help of the equation 2A + B + A, B and then further calculate rate by using the changed [A and [B]. |
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585 | Instantaneous rate and average rate of a reaction are same when ( Delta boldsymbol{t} rightarrow mathbf{0} ) If true enter 1 , else enter 0 |
12 |
586 | Inversion of sugar is pseudo first order reaction. Explain. | 12 |
587 | ( boldsymbol{X} stackrel{text {StepI}}{longrightarrow} boldsymbol{Y} stackrel{text {StepII}}{longrightarrow} boldsymbol{Z} ) is a complex reaction. Total order of reaction is 2 and step II is slow step. What is molecularity of step II? ( A cdot 2 ) B. 1 ( c cdot 3 ) D. 4 |
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588 | Which of the following theory is not related to the chemical kinetics? A. Collision theory B. Absolute theory c. Absolute reaction rate D. vSEPR theory |
12 |
589 | The rate at which a solid dissolves in water is increased by which of the following? I. Crushing the solid into smaller pieces II. Agitating the mixture III. Placing the mixture in an ice bath A. I only B. II only c. I and II only D. I and III only |
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590 | Chemical reactions of the type ( boldsymbol{X} stackrel{boldsymbol{k}_{1}}{rightarrow} ) ( boldsymbol{Y} stackrel{boldsymbol{k}_{2}}{rightarrow} boldsymbol{Z} ) are called: A. consecutive reactions B. parallel reactions c. reversible reactions D. chain reactions |
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591 | For the zero order reaction ( boldsymbol{A} rightarrow mathbf{2} boldsymbol{B} ), the rate constant is ( 2 times 10^{-6} M ) min( ^{-1} ). The reaction is started with ( 10 M A ) (i) What will be the concentration of ( A ) after 2 days (ii) What is the initial halflife of the reaction (iii) In what time, the reaction will complete? |
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592 | Q.1 The role of a catalyst is to change ………. (a) Gibbs energy of reaction (b) enthalpy of reaction (c) activation energy of reaction (d) equilibrium constant |
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593 | The specific rate constant of a first order reaction depends on the: A. Concentration of the reactant B. Concentration of the product c. Time D. Temperature |
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594 | The reaction, ( 2 S O_{2(g)}+O_{2(g)} rightleftharpoons ) ( 2 S O_{3(g)} ) is carried out in a ( 1 d m^{3} ) vessel and ( 2 d m^{3} ) vessel separately. The ratio of the reaction velocities will be: A . 1: 8 B. 1: 4 c. 4: 1 D. 8: 1 |
12 |
595 | If its given : Half-life ( alpha frac{1}{a}, ) what will be the order? Will it be ( 2 ? ) |
12 |
596 | At ( 100^{0} C, ) the gaseous reaction ( A rightarrow ) ( 2 B+C ) is found to be of first order Starting with pure ( A, ) if at the end of 10 min, the total pressure of the system is ( 140 mathrm{mm} ) and after a long time it is 300 ( mathrm{nm}, ) the partial pressure of ( boldsymbol{A} ) at the end of ( 10 mathrm{min} ) is: A. 70 mm B. 160 mm ( c cdot 60 mathrm{mm} ) D. 80 mm |
12 |
597 | The activation energy for most of the reaction is approximately ( 50 mathrm{kJ} ) mol ( ^{-1} ) The rate for temperature coefficient for such reaction will be: ( mathbf{A} cdot approx 2 ) в. ( approx 3 ) ( c cdot<1 ) ( D ldots 4 ) |
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598 | The mechanism of the reaction: ( 2 N O+O_{2} longrightarrow 2 N O_{2} ) is, ( N O+N O overbrace{K_{-1}}^{k_{1}} N_{2} O_{2}(f a s t) ) ( N_{2} O_{2}+O_{2} stackrel{k_{2}}{longrightarrow} 2 N O_{2}(s l o w) ) The rate constant of the reaction is : A ( cdot k_{2} ) B. ( k_{2} k_{1}left(k_{-1}right) ) ( c cdot k_{2} k ) D. ( k_{2}left(frac{k_{1}}{k_{1}}right) ) |
12 |
599 | Question 24. With the help of an example explain what is meant by pseudo first order reaction. |
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600 | Half life period of a first order reaction, ( A rightarrow ) product is 6.93 hour. What is the value of rate constant? A ( cdot 1.596 h^{-1} ) B. ( 0.1 h^{-1} ) c. ( 4.802 h^{-1} ) D. ( 10 h^{-1} ) |
12 |
601 | The temperature dependence of rate constant ( (k) ) of a chemical reaction is written in terms of Arrhenius equation, ( boldsymbol{k}=boldsymbol{A} boldsymbol{e}^{-boldsymbol{E}_{a} / boldsymbol{R} boldsymbol{T}} . ) Activation energy ( left(boldsymbol{E}_{boldsymbol{a}}right) ) of the reaction can be calculated by plotting: ( mathbf{A} cdot log k ) vs ( T ) B. ( log k ) vs ( frac{1}{T} ) c. ( k ) vs ( T ) D. ( k ) vs ( frac{1}{log T} ) |
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602 | The decomposition ( N H_{3} ) gas on a heated tungsten surface gave the following results: Initial pressure 65 105 [ (mathrm{mm}) ] Half-life [ begin{array}{lll} text { 290 } & text { x } & text { 670 } end{array} ] ( (mathrm{sec}) ) Calculate approximately the values of ( x ) and ( y ) A. ( x=410 ) sec, ( y=115 ) mm B. ( x=467 ) sec, ( y=150 mathrm{mm} ) C ( . x=490 ) sec, ( y=120 mathrm{mm} ) D. ( x=430 ) sec ( , y=105 mathrm{mm} ) |
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603 | 13. Starting with a sample of pure Cu, 7/8 of it decays in Zn in 15 min. The corresponding half-life is (a) 75 min (b) 5 min (c) 15 min (d) 10 min (AIEEE 2005) 27 |
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604 | The gas phase decomposition of dimethyl ether follows first order kinetics: ( boldsymbol{C H}_{3}-boldsymbol{O}-boldsymbol{C H}_{3}(boldsymbol{g}) rightarrow boldsymbol{C H}_{4}(boldsymbol{g})+ ) ( boldsymbol{H}_{2}(boldsymbol{g})+boldsymbol{C} boldsymbol{O}(boldsymbol{g}) ) The reaction is carried out in a constant volume container at ( 50^{circ} mathrm{C} ) and has a half life of 14.5 minutes. Initially, only dimethyl ether is present at a pressure of 0.40 atm. What is the total pressure of the system after 12 minutes? (Assume the ideal gas behaviour.) A. 0.946 atm B. 0.785 atm ( c cdot 0.777 ) atm D. 0.749 atm |
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605 | A certain radioactive isotope decay has ( alpha ) -emission, ( A_{1} X longrightarrow A_{1}-4 ) ( Z_{1} ) half life of ( boldsymbol{X} ) is 10 days. If 1 mol of ( boldsymbol{X} ) is taken initially in a sealed container, then what volume of helium will be collected at STP after 20 days? A ( .22 .4 L ) B. ( 11.2 L ) c. ( 16.8 L ) D. ( 33.6 L ) |
12 |
606 | reactor containing a movable but weight loss piston is nlled with 1(M) solution of H.O, solution in water. H,O, undergoes first-order decomposition with the half-life period hours at 300 K. As gas decomposes, the piston moves up against the external pressure of 1 atm. R=0.08 L atm K-mol-!. Given: exp(-0.693x) = 0.435; expl-0.693x}) = 0.379 19. What is the work done by the gas from the start of seventh hour till the end of tenth hour? (a) 2.52 kJ (b) 1.25 kJ (c) 0.231 kJ (d) none of these |
12 |
607 | Cyclopropane rearranges to form propene: ( triangle rightarrow boldsymbol{C H}_{2}-boldsymbol{C H}=boldsymbol{C H}_{2} ) This follows first-order kinetics. The rate constant is ( 2.714 times 10^{-3} s e c^{-1} . ) The initial concentration of cyclopropane is ( 0.29 M . ) What will be the concentration of cyclopropane after 100 sec? A. ( 0.035 M ) B. ( 0.22 M ) c. ( 0.145 M ) D. ( 0.0018 M ) |
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608 | In a reaction; ( 2 A rightarrow ) Products, the concentration of ( boldsymbol{A} ) decreases from 0.5 mol litre ( ^{-1} ) to 0.4 mol litre( ^{-1} ) in 10 minutes. Calculate rate during this interval. |
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609 | A reaction takes place in three steps. The rate constant of the three steps is ( boldsymbol{K}_{1}, boldsymbol{K}_{2} ) and ( boldsymbol{K}_{3} ) respectively. The overall rate constant ( boldsymbol{K}=frac{boldsymbol{K}_{mathbf{1}} boldsymbol{K}_{mathbf{3}}}{boldsymbol{K}_{mathbf{2}}} . ) If the energy of activation for the three steps are 40,30 and ( 20 K J ) respectively, then : This question has multiple correct options A. overall energy of activation is ( 10 mathrm{KJ} ) B. overall energy of activation is ( 30 K J ) C. the reaction mechanism is ( 2 A rightleftharpoons A^{*}+A ; A^{*} frac{K_{3}}{r d s} ) product and overall order is one D. the reaction mechanism is ( A stackrel{K}{rightarrow} B ; B stackrel{K}{longrightarrow} C ; C stackrel{K_{3}}{rightarrow} ) product and overall order is one |
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610 | Consider this reaction. ( 2 N O_{2(g)}+ ) [ boldsymbol{O}_{boldsymbol{3}(boldsymbol{g})} rightarrow boldsymbol{N}_{2} boldsymbol{O}_{boldsymbol{5}(boldsymbol{g})}+boldsymbol{O}_{boldsymbol{2}(boldsymbol{g})} ] The reaction of nitrogen dioxide and ozone represented in first order in ( N O_{2(g)} ) and ( O_{3(g)} . ) Which of these possible reaction mechanisms is consistent with the rate law? [ text { Mechanism I. } quad N O_{2}+O_{3} rightarrow N O_{3}+ ] ( boldsymbol{O}_{2} ) slow [ N O_{3}+N O_{2} rightarrow N_{2} O_{5} ] fast [ text { Mechanism II. } boldsymbol{O}_{3} rightleftharpoons boldsymbol{O}_{2}+boldsymbol{O} ] fast [ N O_{2}+O rightarrow N O_{3} ] slow [ N O_{3}+N O_{2} rightarrow N_{2} O_{5} ] fast A. I only B. II only c. both I and |
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611 | For gaseous reaction what is the unit of rate of reaction? |
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612 | For a first order reaction ( t_{0.75} ) is 138.6 sec. Its specific rate constant is ( left(operatorname{in} s^{-1}right) ) A ( cdot 10^{-2} ) – ( ^{-2} ) B . ( 10^{-6} ) ( mathrm{c} cdot 10^{-4} ) D. ( 10^{-5} ) |
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613 | In bimolecular reaction, the steric factor ( P ) was experimentally determined to be ( 4.5 . ) The correct option(s) among the following is (are): This question has multiple correct options A. the activation energy of the reaction is unaffected by the value of the steric factor B. experimentally determined value of frequency factor is higher than that predicted by Arrheneius equation C . since ( P=4.5 ), the reaction will not proceed unless an effective catalyst is used D. tThe value of frequency factor predicted by Arrhenius equation is higher than that determined experimentally |
12 |
614 | Q. 42 For a general reaction A general reaction A B. plot of concentrat B. plot of concentration of Ays time is given in figure. Answer the following questions on the basis on (i) What is the order of the reaction? (ii) What is the slope of the curve? (iii) What are the units of rate constant? А — В Conc. of A – Time (t) |
12 |
615 | Fill up the following with suitable terms. (i) Activation energy ( = ) Threshold energy – (ii) Half-life period of zero order reaction ( = ) (iii) Average rate of reaction ( = ) (iv) Instantaneous rate of reaction ( = ) A ( cdot ) potential energy, ( frac{0.693}{k}, frac{d x}{d t}, frac{Delta[A]}{Delta t} ) B. Energy of reactants, ( frac{1}{k}, frac{Delta[A]}{Delta t}, frac{d x}{d t} ) C. Energy of reaction, ( frac{log k}{t}, frac{Delta[A]}{Delta t}, frac{d x}{d t} ) Derage kinetic energy of reactants, ( frac{a}{2 k}, frac{Delta[A]}{Delta t}, frac{d x}{d t} ) |
12 |
616 | Q.50 Why can’t molecularity of any reaction be equal to zero? antaroton |
12 |
617 | If the door of a refrigerator is kept open in a dosed room then room: A. heated B. cooled c. heated or cooled depending upon the initial temperature of the room D. neither cooled nor heated |
12 |
618 | An optically active compound A upon acid catalysed hydrolysis yield two optically active compound B and ( C ) by pseudo first order kinetics. The observed rotation of the mixture after 20 min was ( 20^{circ} ) while after completion of the reaction it was ( -20^{circ} . ) If optical rotation per mole of ( A, B & C ) are ( 60^{circ}, 40^{circ} ) ( &-80^{circ} . ) Calculate half life of the reaction. A. 20 min B. 24 min c. 28 min D. 32 min |
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619 | The rate constant, the activation energy and the frequency factor of a chemical reaction at ( 25^{circ} mathrm{C} ) are ( 3.0 times 10^{-4} s^{-1} ) ( 104.4 mathrm{KJ} ) mol( ^{-1} ) and ( 6.0 times 10^{14} s^{-1} ) respectively. The value of the rate constant as ( boldsymbol{T} rightarrow infty ) is: A . ( 2.0 times 10^{18} s^{-1} ) B. ( 6.0 times 10^{14} s^{-1} ) ( c cdot alpha ) D. 3.6 ( times 10^{20} s^{-1} ) |
12 |
620 | If ( Delta t rightarrow 0 ) the average rate changes to A . infinitesimal rate B. small rate c. instantaneous rate D. fast rate |
12 |
621 | In a reaction with two reactants, two trials are performed. In both trials, the concentration of reactant ( boldsymbol{A} ) is held constant. If the concentration of reactant ( B ) is |
12 |
622 | In a reaction carried out at ( 400 mathrm{K} ) ( 0.0001 % ) of the total number of collisions are effective. The energy of activation of the reaction is: A . zero B. 7.37 k cal/mol c. ( 9.212 mathrm{k} ) cal/mol D. 11.05 k cal/mol |
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623 | ( mathbf{2} N boldsymbol{O}+boldsymbol{B} boldsymbol{r}_{2} rightarrow boldsymbol{2} boldsymbol{N} boldsymbol{O} boldsymbol{B} boldsymbol{r} ) The reaction obeys the following mechanism: ( N O+B r_{2} stackrel{F a s t}{rightleftharpoons} N O B r_{2} ) ( N O B r_{2}+N O stackrel{S l o w}{longrightarrow} 2 N O B r ) The rate expression of the above reaction can be written as: A ( cdot r=k[N O]^{2}left[B r_{2}right] ) B ( cdot r=k[N O]left[B r_{2}right] ) C ( cdot r=k[N O]left[B r_{2}right]^{2} ) D . ( r=kleft[N O B r_{2}right. ) |
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624 | What specific name can be given to the following sequence of steps: ( H g+h v rightarrow ) ( H g^{*} ) ( H g^{*}+H_{2} rightarrow H_{2}^{*}+H g ) A. Fluorescence B. Phosphorescence c. Photosensitization D. Chemilumionescence |
12 |
625 | Find the two third life ( left(t_{2 / 3}right) ) of a first order reaction in which ( boldsymbol{K}=mathbf{5 . 4 8} times ) ( 10^{-14} s e c^{-1} ) A ( cdot t_{2 / 3}=5 times 10^{13} ) sec B . ( t_{2 / 3}=2 times 10^{13} ) sec C ( cdot t_{2 / 3}=1.25 times 10^{13} mathrm{sec} ) D. none of these |
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626 | Q.57 Assertion (A) Order of the reaction can be zero or fractional, Reason (R) We cannot determine order from balanced chemical equation. Both ti not the correct yplanation of |
12 |
627 | In a certain reaction. ( 10 % ) of the reactant decomposes in one hour, ( 20 % ) in two hours, ( 30 % ) in three hours, and so on. The dimension of the velocity constant (rate constant) are: A ( cdot h r^{-1} ) B. ( operatorname{Mol} L^{-1} h r^{-1} ) c. ( L m o l^{-1} s^{-1} ) D. Mols” |
12 |
628 | Calculate the age of a vegetarian beverage whose tritium content is only ( 15 % ) of the level in living plants. Given ( boldsymbol{t}_{frac{1}{2}} ) for ( _{1} boldsymbol{H}^{3}=mathbf{1 2 . 3} ) years. ( (log mathbf{2}= ) ( 0.3, log 3=0.48) ) |
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629 | For the chemical reaction ( N_{2}(g)+ ) ( mathbf{3} boldsymbol{H}_{mathbf{2}}(boldsymbol{g}) rightleftharpoons mathbf{2} boldsymbol{N} boldsymbol{H}_{mathbf{3}}(boldsymbol{g}) ) the correct option is: A ( cdot-frac{1}{3} frac{dleft[H_{2}right]}{d t}=-frac{1}{2} frac{left[N H_{3}right.}{d t} ) B. ( -frac{dleft[N_{2}right]}{d t}=2 frac{dleft[N H_{3}right]}{d t} ) c. ( -frac{dleft[N_{2}right]}{d t}=frac{1}{2} frac{dleft[N H_{3}right]}{d t} ) D. ( 3 frac{dleft[H_{2}right]}{d t}=2 frac{dleft[N H_{3}right]}{d t} ) |
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630 | Units of rate of reaction are mole ( l^{-1} s^{-1} ) A . True B. False |
12 |
631 | What is the unit for the rate constant of a second order reaction? A ( cdot s^{-1} ) B. mol ( L^{-1} ) c. mol ( L^{-1} s^{-1} ) D. ( mathrm{L} ) mol ( ^{-1} s^{-1} ) E ( cdot operatorname{mol}^{2} L^{-2} s^{-2} ) |
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632 | The correct expression for the rate of reaction of elementary reaction, ( boldsymbol{A}+ ) ( B rightarrow C ) is : ( mathbf{A} cdot frac{d[C]}{d t}=K[A] ) ( mathbf{B} cdot frac{d[C]}{d t}=K[B] ) ( mathbf{C} cdot frac{-d[A]}{d t}=K[A][B] ) ( mathbf{D} cdot frac{-d[A]}{d t}=K[A] ) |
12 |
633 | Molecules must collide before they react. If true enter ( 1, ) if false enter 0 |
12 |
634 | Question 14. 14 The He The half-life for radioactive decay of d inactive decay of 14 C is 5730 yr. An us archaeological artifact containing wood had only 80% of the *C found in a living tree. Estimate the age of the sample. Since, all the radioactive processes follow first order kinetics calculate rate constant fromty, as k = 0.693/t12. (in Then, put the value of k in the expression of first order rate constant to findt. 0,693 0,693 |
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635 | anism Q. 30 Mark the incorrect statements. (a) Catalyst provides an alternative pathway to reaction mecha (b) Catalyst raises the activation energy (c) Catalyst lowers the activation energy (d) Catalyst alters enthalpy change of the reaction |
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636 | Two molecules collide and a reaction not occur. Which of the following is not a valid explanation for this? A. The molecules were not in the proper states of matter. B. The molecules did not have enough kinetic energy. C. The molecules were not oriented correctly when they struck each other D. The temperature of the reaction mixture was not high enough. |
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637 | If the rate of reaction is equal to the rate constant, the order of the reaction is: A. 0 B. ( c cdot 2 ) ( D ) |
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638 | The rate of chemical reaction is directly proportional to the equilibrium constant.
In which of the following process reaction will be completed first? |
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639 | ( ln 20 ) minutes of ( 80 % ) of ( N_{2} O_{5} ) is decomposed. Rate constant is: [ begin{array}{l} mathrm{N}_{2} mathrm{O}_{5} stackrel{mathrm{Keq}}{longleftarrow} mathrm{NO}_{2}+mathrm{NO}_{3}(text { fast equilibrium }) \ mathrm{NO}_{2}+mathrm{NO}_{3} frac{mathrm{k}_{1}}{ } mathrm{NO}_{2}+mathrm{NO}+mathrm{O}_{2}(text { slow }) \ mathrm{NO}+mathrm{NO}_{3} frac{mathrm{k}_{2}}{longrightarrow} 2 mathrm{NO}_{2}(text { fast }) end{array} ] A . 0.08 B. 0.05 c. 0.12 D. 0.2 |
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640 | When molecules of type A react with molecules of type B in one-step process to give ( A B_{2} ), then the rate law is? A ( cdot ) rate ( =K[A]^{1}[B]^{2} ) B . rate ( =K[A]^{2}[B]^{1} ) c. rate ( =K[2 A][B] ) D. rate=K [A][B] |
12 |
641 | The gas phase decomposition of dimethyl ether follows first order kinetics, ( boldsymbol{C H}_{3} boldsymbol{O C H}_{3}(boldsymbol{g}) rightarrow boldsymbol{C H}_{2}(boldsymbol{g})+boldsymbol{H}_{2}(boldsymbol{g})+ ) ( boldsymbol{C O}(boldsymbol{g}) ) The reaction is carried out in a constant volume container at ( 500^{circ} mathrm{C} ) and has a half-life of 14.5 minute. Initially only dimethyl ether is present at a pressure of 0.40 atmosphere. The total pressure of the system after 12 minutes assuming ideal gas behaviour in atm is (write answer as the first integer after decimal, e.g., if answer is 2.56 then answer should be 5 ) |
12 |
642 | At ( 300 K, ) the initial pressure of a reactant ( R ) is 100 mm. After 60 secs, the pressure becomes 75 mm. Find the average rate of the reaction. A ( cdot 10 times 10^{-5} ) molL ( ^{-1} ) se ( c^{-1} ) B. ( 5 times 10^{-5} ) molL ( ^{-1} ) sec ( ^{-1} ) C. ( 4.22 times 10^{-5} ) molL ( ^{-1} ) sec ( ^{-1} ) D. ( 2.22 times 10^{-5} ) molL ( ^{-1} ) sec ( ^{-1} ) |
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643 | The unit of rate constant for a zero order reaction is: A ( cdot operatorname{mol} L^{-1} s^{-1} ) B. ( L ) mol ( ^{-1} s^{-1} ) c. ( L^{2} ) mol ( ^{-2} s^{-1} ) D. ( s^{-1} ) |
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644 | For a zero-order reaction ( boldsymbol{A} rightarrow ) product the rate constant is ( 10^{-2} ) mol ( L^{-1} s^{-1} ) Starting with 10 moles of ( A ) in a 1 L vessel, how many moles of ( A ) would be left unreacted after 10 minutes? A. 5 moles B. 6 moles c. 4 moles D. 10 moles |
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645 | 0.54 Match the statements given in Column I and Column II. Column 1 Column II A Catalyst alters the rate of 1 1. Cannot be fraction or zero reaction Molecularity 2 Proper orientation is not there Second half-life of first order 3. By lowering the activation reaction energy is same as the first Energetically favourable Total probability is one reactions are sometimes slow Area under the Maxwell, Refers to the fraction of Boltzmann curve is constant molecules with energy equal to or greater than activation energy e-E/RT |
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646 | The activation energy for a chemical reaction depends upon: A. reaction B. nature of reacting species c. frequency factor D. concentration of reacting species |
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647 | For gaseous reaction, the rate is often expressed in terms of dP/dt instead of dc/dt or dn/dt (where c is the concentration and ( n ) the number of mol) What is the relation among these three expressions? A ( cdot frac{d c}{d t}=frac{1}{V}left(frac{d n}{d t}right)=frac{1}{R T}left(frac{d P}{d t}right) ) в. ( frac{d c}{d t}=left(frac{d n}{d t}right)=left(frac{d P}{d t}right) ) ( ^{mathbf{c}} cdot frac{d c}{d t}=left(frac{d n}{d t}right)=frac{V}{R T}left(frac{d P}{d t}right) ) D. None of these |
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648 | Which of the following is not a first order reaction? A. Decomposition of ( H_{2} O_{2} ) B. Decomposition of ( N_{2} O_{5} ) C. Decomposition of ( N_{2} O ) D. Decomposition of ( S O_{2} C l_{2} ) |
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649 | What is a rate constant? A. Equality constant B. Shows relation between rate of reaction and pressure C. Proportionality constant between rate of reaction and concentration D. None of above |
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650 | ( N_{2} O_{5} ) decomposes according to equation: [ mathbf{2} N_{2} boldsymbol{O}_{mathbf{5}} rightarrow mathbf{4} boldsymbol{N} boldsymbol{O}_{mathbf{2}}+boldsymbol{O}_{mathbf{2}} ] What does ( -frac{boldsymbol{d}left[boldsymbol{N}_{2} boldsymbol{O}_{5}right]}{boldsymbol{d} t} ) denote? |
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651 | ( N_{2}(g)+3 H_{2}(g) rightleftharpoons 2 N H_{3}(g)+22 ) kcal. The activation energy for the forward reaction 50 kcal. What is the activation energy for the backward reaction? A . 72 kcal B. 28 kcal c. -72 kcal D. -28 kcal |
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652 | What is activation energy? | 12 |
653 | In a fermentation tank, molasses solution is mixed with yeast enzymes. After three days alcohol was observed. The speed of the reaction in this case is A. slow B. medium ( c . ) fast D. very fast |
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654 | The rate of reaction, ( boldsymbol{A}+boldsymbol{B} longrightarrow ) Products, is given by the equation, ( r= ) ( boldsymbol{k}[boldsymbol{A}][boldsymbol{B}] . ) If ( boldsymbol{B} ) is taken in large excess, the order of reaction would be: A .2 B. c. 0 D. Unpredictable |
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655 | Q. 19 The value of rate constant of a pseudo first order reaction (a) depends on the concentration of reactants present in small amount (b) depends on the concentration of reactants present in excess (c) is independent of the concentration of reactants (d) depends only on temperature otion denen |
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656 | The half-life of a radiosotope is four hours. If the initial rate of the isotope was 200 dpm, the rate after 24 hours is: A. 6.25 dpm B. 2.084 dpm c. 3.125 dpm D. 4.167 dpm |
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657 | The reaction: ( O C l^{-}+I^{-} stackrel{O H^{-}}{longrightarrow} O I^{-}+ ) ( C l^{-} ) takes place in following steps: (i) ( O C l^{-}+H_{2} O stackrel{K_{1}}{kappa_{2}} H O C l+O H^{-} ) (fast) (ii) ( I^{-}+H O C l stackrel{K_{3}}{longrightarrow} H O l+C l^{-} ) (slow) ( left(text { iii) } O H^{-}+H O I_{K_{2}^{prime}}^{K_{1}^{prime}} H_{2} O+O I^{-}(text {fast })right. ) The rate of expression in terms of rate of consumption of ( I^{-} ) is : A ( cdot frac{-d I}{d t}=K cdot frac{[O C l] mid I}{int_{O H} mid}^{-} ) B. ( frac{d I text { – }}{d t}=K cdot frac{[O C l][I]}{[O H]^{2}} ) c. ( frac{d I}{d t}=K cdot frac{(O C l)^{2} I}{[rho H]} ) D. None of these |
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658 | The following results have been obtained during the kinetic studies of the reaction: ( mathbf{2} boldsymbol{A}+boldsymbol{B} rightarrow boldsymbol{C}+boldsymbol{D} ) Experiment ( quad[A] / m o l L^{-1} quad[B] / m o l L^{-1} ) begin{tabular}{lll} 1 & 0.1 & 0.1 \ hline 11 & 0.3 & 0.2 \ hline ( mathrm{III} ) & 0.3 & 0.4 \ & & \ & & \ & & \ ( mathrm{V} ) & 0.4 & 0.1 \ & & end{tabular} Determine the rate law and the rate constant for the reaction. |
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659 | The decomposition of dinitrogen monoxide gas occurs in two steps: ( operatorname{Step} 1: N_{2} O_{(g)} rightarrow N_{2(g)}+O_{(g)} ) (slow) Step ( mathbf{2}: mathbf{N}_{mathbf{2}} boldsymbol{O}_{(boldsymbol{g})}+boldsymbol{O}_{(boldsymbol{g})} rightarrow boldsymbol{N}_{mathbf{2}(boldsymbol{g})}+boldsymbol{O}_{boldsymbol{2}(boldsymbol{g})} ) (fast) What is the overall reaction? A ( cdot 2 N_{2} O_{(g)} rightarrow 2 N_{2(g)}+O_{2(g)} ) B ( cdot 2 N_{2} O_{(g)}+O_{(g)} rightarrow 2 N_{2(g)}+O_{2(g)} ) C. ( 2 N_{2} O_{(g)}+O_{(g)} rightarrow 2 N_{2(g)}+O_{2(g)}+O_{(g)} ) D. ( N_{2} O_{(g)} rightarrow N_{2(g)}+O_{2(g)} ) |
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660 | The rate constant for forward and backward reaction of hydrolysis of ester are ( 1.1 times 10^{-2} ) and ( 1.5 times 10^{-3} ) per minute respectively Equilibrium constant for the reaction is ( C H_{3} C O O C_{2} H_{5}+H_{2} O rightleftharpoons ) ( boldsymbol{C H}_{3} boldsymbol{C O O H}+boldsymbol{C}_{2} boldsymbol{H}_{5} boldsymbol{O} boldsymbol{H} ) A .4 .33 B. 5.33 ( c cdot 6.33 ) D. 7.33 |
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661 | The experimental data for decomposition of ( N_{2} O_{5}left[2 N_{2} O_{5} rightarrowright. ) ( left.4 N O_{2}+O_{2}right] ) in gas phase at ( 318 K ) are given below: [ text { t/s } quad mathbf{0} quad mathbf{4 0 0} quad mathbf{8 0 0} ] [ 10^{2} ] [ left[N_{2} O_{5}right] / m o l L^{-1} ] (i) Plot ( left[N_{2} O_{5}right] ) against t. (ii) Find the half-life period for the reaction. (iii) Draw a graph between ( log left[N_{2} O_{5}right] ) and t. (iv) What is the rate law? (v) Calculate the rate constant. (vi) Calculate the half-life period from ( mathbf{k} ) and compare it with (ii) |
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662 | The reaction ( 2 N O+B r_{2} rightarrow 2 N O B r ) is supposed to follow the following mechanism (i) ( N O+B r_{2} rightleftharpoons N O B r_{2} ) (ii) ( N O B r_{2}+N O stackrel{s l o w}{rightarrow} 2 N O B r ) The rate law expression is: A ( cdot r=K^{prime}[N O]^{2}left[B r_{2}right] ) B . ( r=K^{prime}[N O]^{2}left[B r_{2}right]^{2} ) c. ( r=K^{prime}[N O]left[B r_{2}right. ) D . ( r=K^{prime}[N O]^{1}left[B r_{2}right] ) |
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663 | The number of molecules of the reactants taking part in a single step of the reaction is indicative of : A. order of a reaction B. Molecularity of a reaction c. Fast step of the mechanism of a reaction D. Half-life of the reaction |
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664 | What causes an increase in effective collisions without increasing average energy? A. An increase in the reactant concentration B. An increase in the temperature c. A decrease in pressure D. catalysts |
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665 | For a general gaseous reaction of the type ( R rightarrow P ), if the initial concentration of ( boldsymbol{R} ) is doubled, half-life of the reaction is also doubled, the order of that reaction is: A . B. ( c cdot 2 ) D. 3 |
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666 | ( mathbf{2} N boldsymbol{O}(boldsymbol{g})+boldsymbol{C l}_{2}(boldsymbol{g}) rightarrow boldsymbol{2} boldsymbol{N} boldsymbol{O} boldsymbol{C l}(boldsymbol{g}) ) The following data were collected. All the measuremnets were taken at ( 263 mathrm{K} ) Initial rate disappear: ( begin{array}{llll}begin{array}{l}text { Experiment } \ text { No. }end{array} & begin{array}{l}text { Initial } \ text { [NO] } \ text { (M) }end{array} & begin{array}{l}text { Initial } \ {left[C_{2}right]} \ text { (M) }end{array} & begin{array}{l}text { In } \ text { di }end{array} \ & & text { of }end{array} ) ( C l_{2} ) or ( C l_{2} ) ( (M / m i n) ) 0.15 0.15 0.60 0.15 ( quad 0.30 ) 1.20 3 ( begin{array}{ll}text { 0.30 } & text { 0.15 }end{array} ) 2.40 0.25 0.25 (a) Write the expression for rate law. (b) Calculate the value of rate constant and specify its units. (c) What is the initial rate of disappearance of ( C l_{2} ) in exp. ( 4 ? ) |
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667 | A first order reaction takes 40 min for ( 30 % ) decomposition. Calculate ( t_{1 / 2} ) |
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668 | In a certain reaction, ( 10 % ) of the reactant decomposes in one hour, ( 20 % ) in two hours, ( 30 % ) in three hours and so on. Dimension of the velocity constant are: A . hour ( ^{-1} ) B. mole litre ( ^{-1} ) hour ( ^{-1} ) c. litre mol- ( ^{1} ) hour ( ^{-1} ) D. mole sec ( ^{-1} ) |
12 |
669 | A chemical reaction ( 2 A rightleftharpoons 4 B+C ) in gas phase occurs in a closed vessel. The concentration of ( B ) is found to be increased by ( 5 times 10^{-3} ) mole 1: 1 in 10 second. Calculate ( C O ) the rate of appearance of ( B ) (ii) the rate of disappearance of ( boldsymbol{A} ) |
12 |
670 | For a first order reaction, ( (A) rightarrow ) product the concentration of A changes from 0.1 M to ( 0.025 mathrm{M} ) in 40 minutes. The rate of reaction when the concentration of A is ( 0.01 mathrm{M}, ) is: A ( cdot 1.73 times 10^{-5} mathrm{Mmin}^{-1} ) В. ( 3.47 times 10^{-4} ) М ( min ^{-1} ) ( mathbf{c} cdot 3.47 times 10^{-5} mathrm{Mmin}^{-1} ) D. ( 1.73 times 10^{-4} mathrm{M} min ^{-1} ) |
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671 | Question 26. The decomposition of hydrocarbon follows the equation k=(4.5 x10″ s-le-28000 K/T. Calculate the activation energy Ea. Compare the given equation with the Arrhenius equation, k = Ae Ea! R’ to find the value of Ez |
12 |
672 | For the reaction ( 4 N H_{3}+5 O_{2} rightarrow ) ( 4 N O+6 H_{2} O, ) the rate disappearance of ammonia is ( 3.6 times 10^{-3} ) mol ( L^{-1} s^{-1} ) What is the rate of formation of water? |
12 |
673 | Assertion The order of a reaction can have fractional value. Reason The order of a reaction cannot be written from balanced equation of a reaction. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is correct but Reason is incorrect D. Both Assertion and Reason are incorrect |
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674 | The rate constant of reaction changes when: A. volume is changed B. concentration of the reactants are changed c. temperature is changed D. pressure is changed |
12 |
675 | The mechanism of the reaction: ( N u^{-}+R-X rightarrow R-N u+X^{-} ) is: ( N u^{-}+R-X rightarrow[text { Transition state }] ) (slow) [Transition state] ( rightarrow N u-R+ ) ( X^{-}(text {fast }) ) The rate of reaction can be increased by: A. increasing the cone, of ( N u^{-} ) only B. increasing the core, of ( R-X ) only c. increasing the cone, of both ( N u^{-} ) and ( R-X ) D. decreasing the cone, of both ( N u^{-} ) and ( R-X ) |
12 |
676 | What is the formula to find the value of ( t_{1 / 2} ) for a zero order reaction? A. ( frac{k}{[R]_{0}} ) в. ( frac{2 k}{[R]_{0}} ) c. ( frac{[R]_{0}}{2 k} ) D. ( frac{0.693}{k} ) |
12 |
677 | In a reaction mechanism consisting of elementary reaction steps where the relative rate of each is given, which of the following is most likely to be the rate-determining step? A. A step labeled fast B. A step labeled moderate C. A step labeled slow D. It is not possible to tell which step is rate determining from this information |
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678 | The rate constant of a chemical reaction at a very high temperature will approach: A. Arrhenius frequency factor divided by the ideal gas constant B. Activation energy C. Arrhenius frequency factor D. Activation energy divided by the ideal gas constant |
12 |
679 | Discuss the characteristics of order of a reaction. |
12 |
680 | A chemical reaction occurs as a result of collisions between reacting molecules. Therefore, the reaction rate is given by: This question has multiple correct options A. total number of collision occuring in a unit volume per second B. fraction of molecules which possess energy less than the threshold energy c. total number of effective collisions D. none of the above |
12 |
681 | When the concentration of a reactant in reaction ( A rightarrow B ) is increased by 8 times but rate increases only 2 times, the order of the reaction would be ( 1 / n ) value of ( n ) is ( ? ) |
12 |
682 | If the concentration of reactants is reduced by n times then the value of rate constant of the first order will? A. Increase by n times B. Decrease by factor of ( n ) c. Not change D. None of these |
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683 | In a reversible reaction, the enthalpy change and the activation energy in the forward direction are respectively ( -boldsymbol{x} boldsymbol{k} boldsymbol{J} boldsymbol{m o l}^{-1} ) and ( boldsymbol{y} boldsymbol{k} boldsymbol{J} boldsymbol{m o l}^{-1} ) Therefore, the energy of activation in the backward direction, in ( k J ) mol ( ^{-1} ) is: A ( cdot(y-x) ) в. ( (x+y) ) c. ( (x-y) ) D. ( -(x+y) ) |
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684 | A catalyst lower the activation energy of a reaction from ( 20 mathrm{kJ} ) mole ( ^{-1} ) to ( 10 mathrm{kJ} ) mol ( ^{-1} ). The temperature at which the uncatalysed reaction will have the same rate as that of the catalyzed at 27 ( o C ) is: A ( cdot-123^{circ} C ) B. ( 327^{circ} mathrm{C} ) ( mathbf{c} cdot 150^{circ} mathrm{C} ) ( mathrm{D} cdot+23^{circ} mathrm{C} ) |
12 |
685 | For zero order reactions, the linear plot was obtained for ( [A] ) vs t. The slope of the line is equal to: ( A cdot k_{0} ) B. ( -k_{0} ) c. ( frac{0.693}{K_{o}} ) D. ( -frac{K_{o}}{2.303} ) |
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686 | For the ( 1^{s t} ) order reaction, ( A(g) rightarrow ) ( mathbf{2} boldsymbol{B}(boldsymbol{g})+boldsymbol{C}(boldsymbol{s}), boldsymbol{t}_{mathbf{1} / mathbf{2}}=mathbf{2 4} ) min. The reaction is carried out taking a certain mass of ‘A’ enclosed in a vessel in which it exerts a pressure of ( 400 mathrm{mm} ) Hg. The pressure of the reaction mixture after the expiry of 48 min will be: ( A cdot 700 mathrm{mm} ) B. 600 mm c. ( 500 mathrm{mm} ) D. ( 1000 mathrm{mm} ) |
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687 | For a reversible reaction, ( boldsymbol{A}+boldsymbol{B} rightleftharpoons boldsymbol{C}+ ) ( D, ) the graph for rate of reaction with time is given below. Mark the terms ( (p),(q) ) and ( (r) ) A ( cdot(p)- ) rate of backward reaction (q) – rate of forward reaction (r) – equilibrium B. (p) – rate of forward reaction, (q) – rate of backward reaction, (r) – equilibrium c. (p) – concentration of products (q) – concentration of reactants, (r) – rate of reaction D. (p) – instantaneous rate of reaction, (q) – variation of rate, (r) – average rate of reaction |
12 |
688 | At a given temperature the rate constant for the decomposition of HI on a metal surface is ( 0.06 M s^{-1}, ) i.e. ( mathbf{2} boldsymbol{H} boldsymbol{I} rightarrow boldsymbol{H}_{2(g)}+boldsymbol{I}_{2(g)} . ) The time taken for the concentration of HI to fall from ( 1.50 mathrm{M} 0.30 mathrm{M} ) is : A . 10 s B. 5 s c. 25 s ( D cdot 8 s ) |
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689 | As the concentration of reactants increases: A. rate of the reaction decreases B. rate of the reaction increases c. rate of the reaction remains the same D. reaction stops |
12 |
690 | The rate constant for a given reaction is ( boldsymbol{K}=mathbf{3} times mathbf{1 0}^{-5} boldsymbol{S}^{-1} boldsymbol{a} boldsymbol{t} boldsymbol{m}^{-1} . ) Express it in units of ( L m o l^{-1} s e c^{-1}(T=273.15 K) ) |
12 |
691 | 0.28 In the graph showing Maxwell, Boltzmann distribution of energy ….. (a) area under the curve must not change with increase in temperature (b) area under the curve increases with increase in temperature (c) area under the curve decreases with increase in temperature (d) with increase in temperature curve broadens and shifts to the right hand side |
12 |
692 | For the gaseous reaction ( 2 A+B rightarrow ) ( C+D, ) the rate is given by ( k[A][B] . ) The volume of the container containing the reaction mixture is suddenly reduced to one-fourth of its original volume. with respect to the original rate, now the rate would be: A ( cdot frac{1}{16} ) times the original rate B . ( frac{1}{8} ) times the original rate c. 16 times the original rate D. 8 times the original rate |
12 |
693 | The rate of certain hypothetical reaction ( A ) ( +mathrm{B}+mathrm{C} rightarrow ) Products, is given by ( r= ) ( -frac{d A}{d t}=k[A]^{1 / 2}[B]^{1 / 3}[C]^{1 / 4} ) The order of a reaction is given by: A . 1 B. ( frac{1}{2} ) ( c cdot 2 ) D. ( frac{13}{12} ) |
12 |
694 | C if the order of Q. 34 Write the rate equation for the reaction 2A + B the reaction is zero. |
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695 | For the reaction: ( mathbf{3} boldsymbol{A}+boldsymbol{B} rightarrow boldsymbol{C}+boldsymbol{D} ) mechanism is Step ( 1: boldsymbol{A}+boldsymbol{B} stackrel{boldsymbol{k}_{1}}{longrightarrow} boldsymbol{E} ) Step ( 2: E+2 A stackrel{k_{2}}{longrightarrow} C+D ) What is the total order of reaction considering steady state approximation? |
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696 | A reaction involving two different reactants: A. can never be a second order reaction. B. can never be a unimolecular reaction c. can never be a bimolecular reaction D. can never be a first order reaction |
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697 | For a reaction ( A+2 B longrightarrow C, ) rate is ( operatorname{given} mathrm{by}+frac{boldsymbol{d}[boldsymbol{C}]}{boldsymbol{d} boldsymbol{t}}=boldsymbol{k}[boldsymbol{A}][boldsymbol{B}], ) hence the order of the reaction is: A . 3 B. 2 c. 1 ( D ) |
12 |
698 | For a first-order reaction, ( boldsymbol{A} rightarrow ) Product the initial concentration of ( A ) is ( 0.1 mathrm{M} ) and after 40 minutes it becomes 0.025 M. Calculate the rate of reaction at reactant concentration of ( 0.01 mathrm{M} ) A ( cdot 3.47 times 10^{-4} mathrm{M} cdot min ^{-1} ) В. ( 3.47 times 10^{-5} mathrm{M} cdot min ^{-1} ) c. ( 1.735 times 10^{-6} ) M. ( min ^{-1} ) D. ( 1.735 times 10^{-4} mathrm{M} . min ^{-1} ) |
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699 | Pseudo first-order rate for the reaction, ( A+B longrightarrow P, ) when studied in ( 0.1 M ) of ( B ) is given by ( -frac{boldsymbol{d}[boldsymbol{A}]}{boldsymbol{d} boldsymbol{t}}=boldsymbol{k}[boldsymbol{A}] ) where ( k=1.85 times 10^{4} mathrm{sec}^{-1} ). Calculate the value of second order rate constant. |
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700 | Why do most chemical reaction rates increase rapidly as the temperature rises A. The fraction of molecular with kinetic energy grater than the activation energy increases rapidly with temperature B. The average kinetic increases as temperature rises C. The activation energy decreases as temperature rise D. More collisions take place between particle so that the reaction can occur |
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701 | dentify the type of reaction indicated by line ( A ) in the diagram. A. Uncatalyzed exothermic B. Catalyzed exothermic c. Catalyzed endothermic E. Reversible |
12 |
702 | The half-life of a zero-order reaction is 30 minutes. What is the concentration of the reactant left after 60 minutes? A . ( 25 % ) B. ( 50 % ) c. ( 6.25 % ) D. 0 |
12 |
703 | ( A stackrel{K_{1}}{longrightarrow} B stackrel{K_{2}}{longrightarrow} C, ) if all reaction are 1st order and ( frac{boldsymbol{d}[boldsymbol{B}]}{boldsymbol{d}[boldsymbol{t}]}=mathbf{0 .} ) Determine ( [boldsymbol{B}] ) A ( cdotleft(K_{1}+K_{2}right)[A] ) B . ( left(K_{1}-K_{2}right)[A] ) c. ( left(K_{1} times K_{2}right)[A ) ( ^{mathrm{D}} cdot frac{K_{1}}{K_{2}} times[A] ) |
12 |
704 | The concentration of the reactant ( R ) at different times are given below. Find the average rate during different time intervals. ( t(sec ) quad[R](operatorname{mol} / L) ) ) 0.150 10 [ 0.100 ] 20 0.050 A ( . . .005 mathrm{mol} mathrm{L}^{-1} mathrm{s}^{-1}, .005 mathrm{mol} mathrm{L}^{-1} mathrm{s}^{-1} ) B . .005molL” ( s^{-1}, .0025 ) molL( ^{-1} s^{-1} ) c. ( .0025 mathrm{molL}^{-1} mathrm{s}^{-1} . .005 mathrm{molL}^{-1} mathrm{s}^{-1} ) D. None of these |
12 |
705 | Calculate the mass of ( C^{14} ) (half life ( = ) ( 5720 text { years }) ) atoms which give ( 3.7 times 10^{7} ) disintegrations per second. |
12 |
706 | For an elementary process ( 2 X+Y rightarrow ) ( Z+W ). the molecularity is- ( A cdot 2 ) B. ( c .3 ) D. unpredictable |
12 |
707 | Question 17. Why in redox titration of KMnO4 vs oxalic acid, we heat oxalic acid solution before starting the titration? |
12 |
708 | For a reaction, the rate constant is expressed as, ( k=A . e^{-40000 / T} ) The energy of the activation is: A. 40000 cal в. 88000 са( l ) c. ( quad 80000 ) cal D. 8000 cal |
12 |
709 | For the reaction, ( A rightarrow B ), the rate law is, rate ( =boldsymbol{k}[boldsymbol{A}] . ) Which of the following statements is incorrect? A. The reaction follows first order kinetics B. The ( t_{1 / 2} ) of the reaction depends on initial concentration c. ( k ) is constant for the reaction at a constant temperature. D. The rate law provides a simple way of predicting the of the reaction |
12 |
710 | A first order reaction takes 23.1 min. for ( 50 % ) completion. Calculate the time required for ( 75 % ) completion of this reaction. ( [text {Given }: log 2=mathbf{0 . 3 0 1}, log mathbf{3}=mathbf{0 . 4 4 7 7 1} ) |
12 |
711 | If 2 g of an isotope has a half-life period of 7 days, the half -life period of 1 g sample is: A. 3.5 days B. 7 days c. 14 days D. 28 days |
12 |
712 | At ( 527^{circ} C ) temperature the activation energy is ( 54.7 mathrm{KJ} / ) mole. The value of Arrhenius factor is ( 4 times 10^{10} ). The rate constant will be A ( cdot 12.28 times 10^{11} ) B . ( 10^{7} ) c. ( 12.28 times 10^{17} ) D. ( 14.58 times 10^{-13} ) |
12 |
713 | What is the mathematical equation for the rate constant for the decomposition of nitrous oxide in presence of platinum catalyst? |
12 |
714 | For a first-order reaction; ( mathbf{A} rightarrow mathbf{B} ), the reaction rate at a reactant concentration of ( 0.01 mathrm{M} ) is found to be ( 2.0 times 10^{-5} ) mole ( L^{-1} s^{-1} . ) The half-life period of the reaction is: A . 300 s в. ( 30 s ) ( c .220 s ) D. 347 |
12 |
715 | For the reaction: ( 2 H I rightarrow H_{2}+I_{2} ). the expression ( frac{-1}{2} frac{d(H I)}{d t} ) represents: A. the rate of formation of ( H I ) B. the rate of disappearance of ( H I ) c. the instantaneous rate of the reaction D. the average rate of reaction |
12 |
716 | The velocity of a reaction is doubled for every ( 10^{circ} mathrm{C} ) rise in temperature. If the temperature is raised to ( 50^{circ} mathrm{C} ), the reaction velocity increases by about: A. 12 times B. 16 times c. 32 times D. 50 times |
12 |
717 | A graph between ( log t_{1 / 2} ) and ( (log mathrm{a}) ) (abscissa) a being the initial concentration of ( A ) in the reaction. For reaction ( A rightarrow ) product, the rate law is: A ( cdot frac{-d(A)}{d t}=k ) B. ( frac{-d(A)}{d t}=k[A] ) ( mathbf{c} cdot frac{-d(A)}{d t}=k[A]^{2} ) D. ( frac{-d(A)}{d t}=k[A]^{3} ) |
12 |
718 | Which of the following can be expected to influence the rate of a chemical reactions? (I) The temperature at which it is carried out. (II) The amount of each specific reactant present. (III) The presence of a catalyst. A . I only B. III only c. I and II only D. Il and III only E . I,II and III |
12 |
719 | The reaction ( boldsymbol{A}(boldsymbol{g})+mathbf{2} boldsymbol{B}(boldsymbol{g}) rightarrow boldsymbol{C}(boldsymbol{g})+ ) ( D(g) ) is an elementary process. In an experiment, the initial partial pressure of ( A ) and ( B ) are ( P_{A}=0.40 ) and ( P_{B}= ) 0.60 atm. When ( P_{C}=0.2 a t m ) and the rate of reaction relative to the initial rate is ? A ( cdot 1 / 48 ) B. 1/24 c. ( 9 / 16 ) D. 1/18 |
12 |
720 | In a multistep reaction, the overall rate of reaction is equal to the : A. Rate of slowest step B. Rate of fastest step c. Average rate of various step D. The rate of last step |
12 |
721 | In a slow reaction, rate of reaction generally with time. A. decreases B. increases c. sometimes increases and sometimes decrease D. remain constant |
12 |
722 | The time elapsed between ( 33 % ) and ( 67 % ) completion of a first order reaction is 30 minutes. What is the time needed for ( 25 % ) completion? A. 15.5 min в. 12.5 min c. 18.5 min D. 16.5 min |
12 |
723 | What is the half – life of a radioactive substance if ( 75 % ) of any given amount of the substance disintegrates in 60 minutes? A. 2 Hours B. 30 Minutes c. 45 Minutes D. 20 Minutes |
12 |
724 | The half-life period of a first-order reaction is 30 min. The percentage of the reactant remaining after 70 min will be: A . 80 B . 40 c. 20 D. 10 |
12 |
725 | The temperature coefficient of the rate of a reaction is ( 2.3 . ) How many times will the rate of the reaction increase if the temperature is raised by ( 25 K ? ) ( (8.02 t i m e s) ) |
12 |
726 | ( boldsymbol{3} boldsymbol{A} longrightarrow boldsymbol{B}+boldsymbol{C} ) It would be a zero-order reaction when: A. The rate of reaction is proportional to square of concentration of ( A ) B. The rate of reaction remains the same at any concentration of ( A ) C. The rate remains unchanged at any concentration of ( B ) and ( C ) D. The rate of reaction doubles if concentration of ( B ) is increased to double |
12 |
727 | For a given reaction ( boldsymbol{A} rightarrow ) Products, rate is ( 1 times 10^{-4} M s^{-1} ) when ( [A]=0.01 mathrm{M} ) and rate is ( 1.41 times 10^{-4} M s^{-1} ) when ( [boldsymbol{A}]=mathbf{0 . 0 2} ) M. Hence, rate law is: A ( cdot-frac{d[A]}{d t}=k[A]^{2} ) B. ( -frac{d[A]}{d t}=k[A] ) ( ^{mathrm{c}}-frac{d[A]}{d t}=frac{k}{4}[A] ) D. ( -frac{d[A]}{d t}=k[A]^{1 / 2} ) |
12 |
728 | Question 9. For a zero order reaction will the molecularity be equal to zero? Explain. |
12 |
729 | Statement: The rate of instantaneous reactions can be determined experimentally. State whether the given statement is true or false. A. True B. False |
12 |
730 | For the reaction shown, which best describes the elementary reaction? ( mathbf{2} N_{2} boldsymbol{O}_{mathbf{5}} leftrightarrow mathbf{4} boldsymbol{N} boldsymbol{O}_{mathbf{2}}+boldsymbol{O}_{mathbf{2}} ) A. First order unimolecular B. Second order unimolecular c. Second order bimolecular D. First order bimolecular |
12 |
731 | The decomposition of ( 2 N_{2} O_{5} rightarrow ) ( 2 N_{2} O_{4}+O_{2} ) is at ( 200^{circ} C . ) If the initial pressure is ( 114 mathrm{mm} ) and after ( 25 mathrm{min} ). of the reaction the total pressure of gaseous mixture is ( 133 mathrm{mm} ). Calculate the average rate of the reaction in a) ( operatorname{atm} min ^{-1} ) b) ( operatorname{mol} L^{-1} s^{-1} ) respectively. A ( .0 .002,8.58 times 10^{-7} ) В. ( 0.001,8.58 times 10^{-7} ) c. ( 0.002,8.58 times 10^{-4} ) D. ( 0.001,8.58 times 10^{-3} ) |
12 |
732 | The rate of a certain reaction increases by 2.3 times when the temperature is raised from ( 300 mathrm{K} ) to ( 310 mathrm{K} ). If ( mathrm{k} ) is the rate constant at ( 300 mathrm{K} ), then the rate constant at ( 310 mathrm{K} ) will be equal to: ( A cdot 2 k ) B. ( c cdot 2.3 k ) ( D cdot 3 k^{2} ) |
12 |
733 | What will be the order of reaction and rate constant for a chemical change having ( log t_{50} % ) vs log concentration of ( (A) ) curves as: A ( .0,1 / 2 ) B. 1,1 c. 2,2 D. 3 |
12 |
734 | The depletion of ozone involves the following steps: Step ( 1: O_{3} frac{K_{1}}{k_{2}} O_{2}+O(text { fast }) ) ( operatorname{step} 2: 0_{3}+O longrightarrow 2 O_{2}(text { slow }) ) The predicted order of the reaction will be: |
12 |
735 | Tollen’s reagent is used for the detection of aldehyde when a solution of ( A g N O_{3} ) is added to glucose with ( N H_{4} O H ) then fluconic acid is formced ( A g^{+}+e^{-} rightarrow A g ) ( boldsymbol{E}_{r e d}^{o}=mathbf{0 . 8} boldsymbol{V} ) ( boldsymbol{C}_{6} boldsymbol{H}_{12} boldsymbol{O}_{6}+boldsymbol{H}_{2} boldsymbol{O} rightarrow boldsymbol{C}_{6} boldsymbol{H}_{12} boldsymbol{O}_{7} ) (Gluconic acid) ( +2 boldsymbol{H}^{+}+mathbf{2} e^{-} ; boldsymbol{E}_{r e d}^{o}= ) ( -0.05 V ) ( A gleft(N H_{3}right)_{2}+e^{-} rightarrow A g(s)+2 N H_{3} ) (Use ( 2.202 times frac{R T}{F}=0.0592 ) and ( frac{F}{R T}= ) ( 38.92 a t 298 K) ) ( mathbf{2} boldsymbol{A} boldsymbol{g}^{+}+boldsymbol{C}_{6} boldsymbol{H}_{22} boldsymbol{O}_{6}+boldsymbol{H}_{2} boldsymbol{O} rightarrow ) ( mathbf{2} boldsymbol{A} boldsymbol{g}(boldsymbol{s})+boldsymbol{C}_{6} boldsymbol{H}_{212} boldsymbol{O}_{7}+mathbf{2} boldsymbol{H}^{+} ) Find ( ln K ) of this reaction? A .66 .13 в. 58.38 c. 28.30 D. 46.29 |
12 |
736 | In acidic medium the rate of reaction between ( left(B r O_{3}right)^{-} ) and ( B r^{-} ) ion is given by the expression. ( -left[boldsymbol{d}left(boldsymbol{B} boldsymbol{r} boldsymbol{O}_{3}^{-}right) / boldsymbol{d} boldsymbol{t}right]= ) ( boldsymbol{K}left[boldsymbol{B} boldsymbol{r} boldsymbol{O}_{3}^{-}right]left[boldsymbol{B r}^{-}right]left[boldsymbol{H}^{+}right]^{2} . ) It means: A. Rate constant of overall reaction is 4 sec( ^{-1} ) B. Rate of reaction is independent of the concentration of acid C. The change in pH of the solution will not affect the rate D. Doubling the concentration of ( H^{+} ) ions will increase the reaction rate by 4 times. |
12 |
737 | Which choice below is the rate law of the following reaction? ( mathbf{2} boldsymbol{H}_{mathbf{2}}(boldsymbol{g})+boldsymbol{O}_{mathbf{2}}(boldsymbol{g}) rightarrow boldsymbol{H}_{mathbf{2}} boldsymbol{O}(boldsymbol{g}) ) A . Rate( =k[H][O] ) B. Rate ( =kleft[H_{2}right]^{x}left[O_{2}right]^{y} ) c. Rate( =kleft[H_{2}right]^{2}left[O_{2}right] ) D. Rate ( =kleft[H_{2}right]left[O_{2}right] ) |
12 |
738 | Write two factors affecting on the rate of chemical reaction. | 12 |
739 | The rate of certain hypothetical reaction ( A+B+C rightarrow ) products is given by ( boldsymbol{r}=-frac{mathbf{d}[boldsymbol{A}]}{mathbf{d} boldsymbol{t}}=boldsymbol{K}[boldsymbol{A}]^{1 / 2} boldsymbol{K}[boldsymbol{B}]^{1 / 3} boldsymbol{K}[boldsymbol{C}]^{1 / 4} ) The order of the reaction: ( A ) в. ( frac{1}{2} ) ( c cdot 2 ) D. ( frac{13}{12} ) |
12 |
740 | In a zero order reaction half life is 100 sec. After how much time 78 fraction of reactant will be reacted? A. 300 sec B. 200 sec ( c . ) 175 sec D. 25 sec |
12 |
741 | The rate constant for two parallel reactions were found to be ( 1.0 times ) ( 10^{-2} d m^{3} m o l^{-1} s^{-1} ) and ( 3.0 times 10^{-2} d m^{3} ) ( m o l^{-1} s^{-1} . ) If the corresponding energies of activation of the parallel reactions are ( 60.0 mathrm{KJ} mathrm{mol}^{-1} ) and ( 70.0 mathrm{KJ} ) mol ( ^{-1} ) respectively, then what is the apparent overall energy of activation? B. 65.0 KJ ( m o l^{-1} ) c. 67.5 к ( operatorname{mol}^{-1} ) D. 100.0 K」 ( m o l^{-} ) |
12 |
742 | Question 23. Describe how does the enthalpy of reaction remain unchanged when a catalyst is used in the reaction? |
12 |
743 | Which one is correct for ( boldsymbol{k}=boldsymbol{A} boldsymbol{e}^{-boldsymbol{E}_{a} / boldsymbol{R} boldsymbol{T}} ) ? A ( cdot E_{a} ) is energy of activation B. R is Rydberg’s constant c. ( mathrm{k} ) is equilibrium constant D. A is adsorption |
12 |
744 | In acidic medium the rate of reaction between ( left(B r O_{3}right)^{-} ) and ( B r^{-} ) ion is given by the expression ( frac{boldsymbol{d}left[boldsymbol{B r} boldsymbol{O}_{3}^{-}right]}{boldsymbol{d} boldsymbol{t}}=boldsymbol{k}left[boldsymbol{B r O}_{3}^{-}right]left[boldsymbol{B r}^{-}right]left[boldsymbol{H}^{+}right]^{2} ) it means: A. rate constant of overall reaction is 4 sec” B. rate of reaction is independent of the conc. of acid c. the change in pH of the solution will not attect the rate D. doubling the conc. of ( H^{+} ) ions will increase the reaction rate by 4 times |
12 |
745 | For a 1 st order reaction of the form, ( A stackrel{k}{longrightarrow} B, ) the correct representations are: ( mathbf{I} ) III ( mathbf{A} cdot I ) and ( I I ) B. III and ( I V ) c. ( I ) and ( I V ) D. II and III |
12 |
746 | If half life of a first order reaction is ( 2.31 times 10^{3} ) min, the time it takes for one-fifth of the reaction to be left behind in min. is ( _{-}-_{-}-_{-}-_{-}-_{-} . ) (give the answer in ( 1000 times ) form |
12 |
747 | A N Q. 6 According to Arrhenius equation ra Arrhenius equation rate constant k is equal to A e. -E/ R Which of the following options represents the graph of Ink vs ! (a) Ink (b) Ink 1/T 1/T (c) ink |
12 |
748 | On increasing temperature from ( 200 mathrm{K} ) to ( 220 mathrm{K} ) rate of reaction ( boldsymbol{A} ) increases by 3 times and rate of reaction ( B ) increases by 9 times then correct relationship between activation energy of ( A ) and ( B ) is: A. ( E_{A}=3 E_{B} ) B ( .3 E_{A}=E_{B} ) ( mathbf{c} cdot E_{B}=2 E_{A} ) D. ( E_{A}=2 E_{B} ) |
12 |
749 | For a chemical reaction, ( boldsymbol{A} longrightarrow boldsymbol{E} ), it is found that rate of reaction is doubled when the concentration of ( A ) is increased four times. The order of the reaction is: A . 1 B. 2 c. ( 1 / 2 ) D. 0 |
12 |
750 | A first order reaction was commenced with ( 0.2 mathrm{M} ) solution of the reactants. If the molarity of the solution falls to ( 0.02 M ) after 100 minutes the rate constant of the reaction is: A ( cdot 2 times 10^{-2} min ^{-1} ) В. ( 2.3 times 10^{-2} min ^{-1} ) c. ( 4.6 times 10^{-2} min ^{-1} ) D. ( 2.3 times 10^{-1} min ^{-1} ) |
12 |
751 | Write the units of rate constants for zero order and first order reactions. |
12 |
752 | The table below shows recorded concentration data for the following chemical reaction: [ begin{array}{l} boldsymbol{C a C l}_{2}(boldsymbol{a q})+mathbf{2 A g} boldsymbol{N} boldsymbol{O}_{3}(boldsymbol{a q}) rightarrow \ boldsymbol{C a}left(boldsymbol{N O}_{3}right)_{2}(boldsymbol{a q})+boldsymbol{2 A g} boldsymbol{C l}(boldsymbol{s}) end{array} ] Use the data to determine the exponents ( x ) and ( y ) in the rate law: [ 0.100 ] [ 0.050 ] ( 6.66 times 10^{-} ) 100 100 ( 13.32 times 10 ) A ( . x=2, y=3 ) B. ( x=1, y=2 ) c. ( x=1, y=1 ) D. ( x=2, y=2 ) |
12 |
753 | ( boldsymbol{A}(boldsymbol{a} boldsymbol{q}) longrightarrow boldsymbol{B}(boldsymbol{a} boldsymbol{q})+boldsymbol{C}(boldsymbol{a} boldsymbol{q}) ) is a first order reaction. Time moles of reagent Reaction progress is measure with help of titration ‘ ( R ) ‘. If all ( A, B ) and ( C ) reacted with reagent and have ‘n’ factors ( [n ) factor; ( left.e q . w t=frac{text { mol.wt. }}{n}right] ) in the ratio of 1: 2: 3 with the reagent. The ( k ) in terms of ( t, n_{1} ) and ( n_{2} ) is : A ( cdot k=frac{1}{t} ln left(frac{n_{2}}{n_{2}-n_{1}}right) ) в. ( quad k=frac{1}{t} ln left(frac{2 n_{2}}{n_{2}-n_{1}}right) ) c. ( _{k}=frac{1}{t} ln left(frac{4 n_{2}}{n_{2}-n_{1}}right) ) D. [ k=frac{1}{t} ln left(frac{4 n_{2}}{5left(n_{2}-n_{1}right)}right) ] |
12 |
754 | Rusting of iron is an example of reaction. A . fast B. slow c. endothermic D. can’t say |
12 |
755 | A first order reaction is found to have a rate constant, ( k=5.5 ; ) find the half life of the reaction. |
12 |
756 | If ( E_{f} ) and ( E_{b} ) are in the ration ( 20: 31 E_{f} ) and ( E_{b} ) at ( 30 mathrm{K} ) respectively are: A. 60 kJ and 93 kJ B. -44 kJ and 93 kJ c. 13 ks and -63 k D. none of these |
12 |
757 | From the following data, the activation energy for the reaction ( (text { cal } / text { mol }) ) is: [ boldsymbol{H}_{2}+boldsymbol{I}_{2} longrightarrow mathbf{2} boldsymbol{H} boldsymbol{I} ] ( T(K) quad 1 / Tleft(K^{-1}right) quad log K ) ( begin{array}{lll}769 & 1.3 times 10^{-3} & 2.9 \ 667 & 1.5 times 10^{-3} & 1.1end{array} ) A ( cdot 4 times 10^{4} ) B. ( 2 times 10^{4} ) ( c cdot 8 times 10^{4} ) D. ( 3 times 10^{4} ) |
12 |
758 | Which of the following choice is correct regarding to increase the rate of a reaction? A. Decreasing the temperature B. Increasing the volume of the reaction vessel c. Reducing the activation energy D. Decreasing the concentration of the reactant in the reaction vessel |
12 |
759 | Match the column | 12 |
760 | The rate of reaction increases with rise in temperature because of : A. increase in the number of activated molecules B. increase in the activation energy C. decrease in the activation energy D. increase in the number of molecular collisions |
12 |
761 | Fora reaction, ( boldsymbol{A} rightarrow boldsymbol{B}+boldsymbol{C}, ) it was found that at the end of 10 minutes from the start, the total optical rotation of the system was ( 50^{circ} ) and when the reaction is complete, it was ( 100^{circ} mathrm{C} ) Assuming that only ( B ) and ( C ) are optically active and dextro rotatory, the rate constant of this first order reaction would be? A ( cdot 0.069 min ^{-1} ) B. 0.69 min ( ^{-1} ) c. 6.9 min ( ^{-1} ) D. ( 6.9 times 10^{-2} ) min ( ^{-1} ) |
12 |
762 | ( frac{k}{c} ) | 12 |
763 | In the following reaction ( 2 H_{2} O_{2}(a q) rightarrow ) ( 2 H_{2} O(l)+O_{2}(g) ) rate of formation of ( O_{2} ) is ( 36 g . m i n^{-1} ) (a) What is rate of formation of ( boldsymbol{H}_{2} boldsymbol{O} ) ? (b) What is rate of disappearance of ( boldsymbol{H}_{2} boldsymbol{O}_{2} ? ) |
12 |
764 | Which among the following reactions is an example of pseudo first order reaction? A. Inversion of cane sugar B. Decomposition of ( H_{2} O_{2} ) c. Conversion of cyclopropane to propene D. Decomposition of ( N_{2} O_{5} ) |
12 |
765 | Question 20. Why can we not determine the order of a reaction by taking into consideration the balanced chemical equation? |
12 |
766 | In a reaction between ( A ) and ( B ), the initial rate of reaction ( left(r_{0}right) ) was measured for different initial concentrations of ( A ) and ( B ) as given below: ( begin{array}{lll}A / m o l L^{-1} & 0.20 & 0.20 \ B / m o l L^{-1} & 0.30 & 0.10end{array} ) ( r_{0} / m o l L^{-1} s^{-1} quad begin{array}{ll}5.07 times & 5.07 times \ 10^{-5} & 10^{-5}end{array} quad begin{array}{l}1.43 times \ 10^{-4}end{array} ) What is the order of the reaction with respect to ( A ) and ( B ? ) |
12 |
767 | Question 16. Thermodynamic feasibility of the reaction alone cannot decide the rate of the reaction. Explain with the help of one example. |
12 |
768 | What is the activation energy for a reaction if the rate doubles when the temperature is raised from ( 20^{circ} mathrm{C} ) to ( mathbf{3 5}^{circ} boldsymbol{C} ?left(boldsymbol{R}=mathbf{8 . 1 3 4} boldsymbol{J} boldsymbol{m o l}^{-mathbf{1}} boldsymbol{K}^{-mathbf{1}}right) ) A ( cdot 15.1 mathrm{kJ} mathrm{mol}^{-1} ) В. 342 k ( J ) mol ( ^{-1} ) ( mathbf{c} cdot 269 k J mathrm{mol}^{-1} ) D. 34.7 kJ mol- |
12 |
769 | Rate constant ( k=2 times ) ( 10^{3} operatorname{mol}^{-1} L s^{-1} ) and ( E_{a}=2.0 times ) ( 10^{2} k J m o l^{-1} . ) What is the value of ( A ) when ( boldsymbol{T} rightarrow infty ? ) A ( .2 .0 times 10^{2} mathrm{mol}^{-1} ) В. ( 2.0 times 10^{3} ) mol( ^{-1} L s^{-1} ) c. ( 2.0 times 10^{3} ) mol ( L^{-1} s^{-1} ) D. 2.0 ( times 10^{3} ) mol ( ^{-1} s^{-1} ) |
12 |
770 | When a catalyst increases the rate of a chemical reaction, the rate constant: A. increases B. decreases c. remains constant D. becomes infinite |
12 |
771 | For certain first-order reaction, ( 75 % ) of the reaction complete in 30 min. How much time did it require to complete ( 99.9 % ) of the reaction? A. 150 min B. 100 min c. 90 min D. 300 min |
12 |
772 | In the given graph. The slope of line ( A B ) gives the information of the: A value of ( frac{E_{a}}{2.303} ) B. value of ( frac{2.30}{E_{0}} ) c. value of ( -frac{E_{a}}{2.303 R} ) ‘D value of ( -frac{E_{a}}{2303 R T} ) |
12 |
773 | A gaseous compound A reacts by three independent first-order processes (as shown in the figure) with rate constant ( 2 times 10^{3}, 3 times 10^{3} ) and ( 1.93 times 10^{3} ) sec ( ^{1} ) for products ( mathrm{B}, mathrm{C} ) and ( mathrm{D} ) respectively. If initially pure ( A ) was taken in a closed container with ( P=8 a t m, ) then the partial pressure of ( mathrm{B}(text { in atm }) ) after 100 sec from the start of experiment: ( mathbf{A} cdot 0.288 ) B. 0.577 c. 1.154 D. noneofthese |
12 |
774 | The rate constant for the reaction, ( mathbf{2} N_{2} O_{5} rightarrow 4 N O_{2}+O_{2} ) is ( 2 times 10^{-5} s^{-1} . ) rate of reaction is ( 1.4 times ) ( 10^{-5} ) mol ( L^{-1} s^{-1}, ) what will be the concentration of ( N_{2} O_{5} ) in mol ( L^{-1} ) ? A. 0.8 B. 0.7 c. 1.2 D. |
12 |
775 | For the reaction, ( N_{2}+3 H_{2} rightleftharpoons 2 N H_{3} ) the rate of change of concentration for hydrogen is ( 0.3 times 10^{-4} M s^{-1} ) The rate of change of concentration of ammonia is ( left(operatorname{in} M s^{-1}right) ) A . ( -0.2 times 10^{-4} ) В. ( 0.2 times 10^{-4} ) c. ( 0.1 times 10^{-4} ) |
12 |
776 | The rate of reaction is doubled for every ( 10^{0} C ) rise in temperature. the increase in reaction rate as a result of rise in temperature from ( 10^{0} C ) to ( 100^{0} C ) is: A . 112 в. 512 c. 400 D. 614 |
12 |
777 | For a first order reaction ( mathbf{A} rightarrow mathbf{P}, ) the temperature (T) dependent rate constant ( (k) ) was found to follow the equation ( log k=-(2000) frac{1}{T}+6.0 ) The pre-exponential factor ( mathbf{A} ) and the activation energy ( mathbf{E}_{mathbf{a}}, ) respectively, are: A . ( 1.0 times 10^{6} mathrm{s}^{-1} ) and ( 9.2 mathrm{kJmol}^{-1} ) В. ( 1.0 times 10^{6} mathrm{s}^{-1} ) and ( 16.6 mathrm{kJmol}^{-1} ) C. ( 6.0 s^{-1} ) and 16.6 kJmol ( ^{-1} ) D. ( 1.0 times 10^{6} mathrm{s}^{-1} ) and ( 38.3 mathrm{kJmol}^{-1} ) |
12 |
778 | Question 13. Calculate the half-life of a first order reaction from their rate constants given below: (i) 200 s-1 (ii) 2 min (iii) 4 yr1 We know that half-life, t12=0.693/k (where, k = rate constant) |
12 |
779 | Assertion: Reactions happen faster at higher temperatures. Reason: As temperatures increase, there is also an increase in the number of collisions with the required activation energy for a reaction to occur A. Both Assertion and Reason are true and Reason is the correct explanation of Assertion B. Both Assertion and Reason are true but Reason is not the correct explanation of Assertion c. Assertion is true but Reason is false D. Assertion is false but Reason is true E. Both Assertion and Reason are false |
12 |
780 | D. 45 Oxygen is available in plenty in air yet fuels do not burn by themselves at room temperature. Explain. |
12 |
781 | The fraction of collisions that posses the energy ( boldsymbol{E}_{boldsymbol{a}} ) is given by: A ( cdot f=e^{frac{-E q}{R T}} ) B . ( f=e^{frac{E}{m}} ) C . ( f=e^{-E a . R T} ) D. ( f=e^{text {Ea. } R T} ) |
12 |
782 | Catalysts lower the activation energy of a reaction: A. Providing a surface and orientation B. Providing an alternative mechanism with a lower activation energy c. Increasing temperature D. Both a and |
12 |
783 | Assertion: If the activation energy of reaction is low, it proceeds at a faster rate.
Reason: Lowering activation energy increases the kinetic energy of molecules. |
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784 | The reaction, ( mathbf{2} N boldsymbol{O}(boldsymbol{g})+boldsymbol{O}_{2}(boldsymbol{g}) leftrightharpoons mathbf{2} boldsymbol{N} boldsymbol{O}_{2}(boldsymbol{g}) ) is first order. If volume of reaction vessel is reduced to ( frac{1}{3}, ) the rate of reaction would be: A ( cdot frac{1}{3} ) times B. ( frac{2}{3} ) times c. 3 times D. 6 times |
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785 | At low pressure, the fraction of the surface covered follows: A. zero-order kinetics B. first order kinetics c. second order kinetics D. fractional order kinetics |
12 |
786 | Molecularity of a reaction can be known from: A. the stoichiometric equation B. the mechanism of the reaction C. the order of the reaction D. the energy of activation of the reaction |
12 |
787 | For a first order reaction, show that time required for ( 99 % ) completion is twice the time required for the completion of ( 90 % ) of reaction. |
12 |
788 | What are the units for the rate of the reaction ( : boldsymbol{A} rightarrow boldsymbol{B} ) ? ( mathbf{A} cdot ) mol.lit( ^{-1} ) B. mol.lit” ( s e c^{-1} ) c. mol.g( ^{-1} ) sec( ^{-1} ) D. mol.kg ( ^{-1} ) sec ( ^{-1} ) |
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789 | 10.38 Derive an expression to calculate time required for completion of zero order reaction. P a r panatia Di |
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790 | The following data were obtained during the first order thermal composition of ( S O_{2} C l_{2} ) at a constant volume. [ boldsymbol{S} boldsymbol{O}_{2} boldsymbol{C l}_{2(boldsymbol{g})} rightarrow boldsymbol{S} boldsymbol{O}_{2(boldsymbol{g})}+boldsymbol{C l}_{2(boldsymbol{g})} ] Total pres Experiment ( quad ) Time ( / ) s ( ^{-1} ) (atm) [ 0.5 ] What is the rate of reaction when total pressure is 0.65 atm? A .0 .35 atm ( s^{-1} ) В. ( 2.235 times 10^{-3} ) atm ( s^{-1} ) c. ( 7.8 times 10^{-4} ) atm ( s^{-1} ) D. ( 1.55 times 10^{-4} ) atm ( s^{-1} ) |
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791 | Question 6. Derive an expression to calculate time required for completion of zero order reaction. |
12 |
792 | Explain with an example how the concentration of the reactants affects the rate of a chemical reaction. |
12 |
793 | A transition state represents the state of highest energy in passing from reactant to product. If true enter 1 , if false enter 0 . |
12 |
794 | In the following gaseous phase first order reaction ( boldsymbol{A}(boldsymbol{g}) rightarrow boldsymbol{2} boldsymbol{B}(boldsymbol{g})+boldsymbol{C}(boldsymbol{g}) ) initial pressure was found to be 400 ( mathrm{mm} ) of ( mathrm{Hg} ) and it changed to ( 1000 mathrm{mm} ) of ( H g ) after ( $ $ 20 $ 4 ) min. Then: This question has multiple correct options A. half life for ( A ) is 10 min B. rate constant is ( 0.0693 mathrm{min}^{-1} ) c. partial pressure of ( C ) at 30 min is 350 mm of ( H g ) D. total pressure after 30 min is 1100 mm of ( H g ) |
12 |
795 | From the graph pick out the correct one: ( mathbf{A} cdot Delta E ) for forward reaction is ( B-A ) ( mathrm{B} cdot Delta E ) for the forward reaction ( C-A ) ( mathrm{C} cdot Delta E ) reverse is greater than forward ( mathbf{D} cdot Delta E ) for forward reaction is ( A+B ) |
12 |
796 | Which of the following do not define instantaneous reactions? A. Appearance of a product over a particular time interval B. Change in the concentration of the products at a particular instant of time C. Change in the concentration of the reactants at a particular instant of time D. Reactions completed in fraction of seconds |
12 |
797 | The higher the temperature A. lower the energy B. higher the energy C. moderate energy D. none of above |
12 |
798 | The rate constant for a first order reaction is ( 60 s^{-1} ). How much time will it take to reduce the initial concentration of the reactant to its ( 1 / 16^{t h} ) value? |
12 |
799 | Observe the following reaction ( : 2 A+ ) ( B rightarrow C . ) The rate of formation of ( C ) is ( 2.2 times 10^{-3} ) mol ( l^{-1} ) min ( ^{-1} . ) The is the value of ( frac{-boldsymbol{d}[boldsymbol{A}]}{boldsymbol{d} boldsymbol{t}}left(text { in } boldsymbol{m o l} boldsymbol{l}^{-1} boldsymbol{m} boldsymbol{i} boldsymbol{n}^{-1}right) ) A ( .2 .2 times 10^{-3} ) В. ( 1.1 times 10^{-3} ) c. ( 4.4 times 10^{-3} ) D. ( 5.5 times 10^{-3} ) |
12 |
800 | From the concentrations of ( mathrm{R} ) at different times given below. Determine the average rate of the reaction range: ( R ) ( rightarrow P ) in given intervals of time. ( t(s) ) [ begin{array}{ll} text { 0 } & text { 5 } end{array} ] ( mathbf{1} ) [ begin{array}{ll} 10^{-3} times & 160 \ end{array} ] 40 ( [R]left(operatorname{mol} L^{-1}right) ) ( mathbf{A} cdot 3.5 times 10^{2} ) to ( 0.42 times 10^{2} ) mol. ( L^{-1} s^{1} ) B . ( 7 times 10^{2} ) to ( 0.84 times 10^{2} ) mol. ( L^{-1} s^{1} ) C . ( 8 times 10^{3} ) to ( 0.37 times 10^{3} ) mol. ( L^{-1} s^{1} ) D. ( 16 times 10^{3} ) to ( 0.75 times 10^{3} ) mol. ( L^{-1} s^{1} ) |
12 |
801 | In the reaction ( boldsymbol{H}_{2} boldsymbol{O}_{2}+boldsymbol{2} boldsymbol{K} boldsymbol{I}+boldsymbol{H}_{2} boldsymbol{S} boldsymbol{O}_{4} ) ( rightleftharpoons 2 H_{2} O+I_{2}+K_{2} S O_{4}, ) the concentration of lodine changes from 0 to ( 20^{-5} ) mol ( L^{-1} ) in 10 secs. Find the average rate of the reaction. A ( cdot 20^{-7} ) molL ( ^{-1} ) sec ( ^{-1} ) B. ( 20^{-4} )mol( L^{-1} )sec( ^{-1} ) c. ( 20^{-5} ) molL ( ^{-1} ) sec ( ^{-1} ) D. ( 20^{-6} )molL( ^{-1} )sec( ^{-1} ) |
12 |
802 | For the reaction ( 2 N H_{3(g)} frac{1130 K}{M o} ) ( N_{2(g)}+3 H_{2(g)}, ) the order is: |
12 |
803 | Q. 59 Assertion (A) The enthalpy of reaction remains constant in the presence of a catalyst. Reason (R) A catalyst participating in the reaction forms different activated complex and lowers down the activation energy but the difference in energy of reactant and product remains the same. |
12 |
804 | For the reaction ( A rightarrow B ), it was found that the concentration of ( B ) increased by 0.3 mol ( L^{-1} ) in 2 hours. What is the average rate of reaction? |
12 |
805 | Express the rate for the following reaction in terms of concentration of reactants and products. ( 5 B r^{-}(a q)+B r O_{3}^{-}(a q)+6 H^{+} rightarrow ) ( mathbf{3} boldsymbol{B} boldsymbol{r}_{2}(boldsymbol{a} boldsymbol{q})+boldsymbol{3} boldsymbol{H}_{2} boldsymbol{O}(l) ) |
12 |
806 | Match the rate law given in column I with the dimensions of rate constant given in column II and mark the appropriate choice. Column I Column I (A) Rate( =kleft[N H_{3}right]^{0} ) (i) ( operatorname{mol} L^{-1} s^{-1} ) (B) ( R a t e=kleft[H_{2} O_{2}right]left[I^{-}right] ) (ii) ( L m o l^{-1} s^{-1} ) (C) ( operatorname{Rate}=kleft[C H_{3} C H Oright]^{3 / 2} ) ( s^{-1} ) (D) ( operatorname{Rate}=kleft[C_{2} H_{5} C lright] ) (iv) ( L^{1 / 2} m o l^{-1 / 2} s^{-1} ) ( mathbf{A} cdot(A) rightarrow(i v),(B) rightarrow(i i i),(C) rightarrow(i i),(D) rightarrow(i) ) B. ( (A) rightarrow(i),(B) rightarrow(i i),(C) rightarrow(i i i),(D) rightarrow(i v) ) c. ( (A) rightarrow(i i),(B) rightarrow(i),(C) rightarrow(i v),(D) rightarrow(i i i) ) D. ( (A) rightarrow(i),(B) rightarrow(i i),(C) rightarrow(i v),(D) rightarrow(i i i) ) |
12 |
807 | The rate constant of a reaction is ( 0.0693 mathrm{min}^{-1} . ) Starting with ( 10 mathrm{mol} ), the rate of the reaction after 10 min is: A. 0.0693 mol ( min ^{-1} ) B. ( 0.0693 times 2 ) mol ( min ^{-1} ) c. ( 0.0693 times 5 ) mol ( min ^{-1} ) D. 0.0693 ( times 5^{2} ) mol ( min ^{-1} ) |
12 |
808 | For a first order reversible reaction ( A_{K_{b}}^{K_{f}} B, ) the initial concentration of ( A ) and ( B ) are ( [A]_{0} ) and zero respectively. If concentrations at equilibrium are ( [boldsymbol{A}]_{e q} ) and ( [boldsymbol{B}]_{e q} ., ) derive an expression for the time taken by ( B ) to attain concentration equal to ( [boldsymbol{B}]_{e q / 2} ) |
12 |
809 | The rate constant of a reaction does not depend upon: A. temperature B. activation energy c. catalyst D. concentration of reactants and products |
12 |
810 | A reaction takes place in three steps with an individual rate constant and activation energy, as given below. Rate constant Activation energy Step 1 ( quad boldsymbol{k}_{mathbf{1}} quad boldsymbol{E}_{boldsymbol{a}_{1}}= ) ( 180 k J / m o l ) Step 2 ( quad boldsymbol{k}_{2} quad boldsymbol{E}_{boldsymbol{a}_{2}}= ) ( mathbf{8 0 k J} / ) mol Step 3 ( quad k_{3} quad quad E_{a_{3}}= ) ( mathbf{5 0 k J / m o l} ) And overall rate constant, ( k= ) ( left(frac{k_{1} k_{2}}{k_{3}}right)^{2 / 3} ) The overall activation energy of the reaction will be: A. ( 140 k J / ) mol в. ( 150 k J / m o l ) c. ( 130 k J / m o l ) D. ( 120 k J / m o l ) |
12 |
811 | Catalytic decomposition of nitrous oxide by gold at ( 900^{circ} mathrm{C} ) at an initia pressure of ( 200 m m ) was ( 50 % ) in 53 minutes and ( 73 % ) in 100 minutes. (a) What is the order of reaction? (b) How much it will decompose in 100 minutes at the same temperature but at an initial pressure of 600 mm? |
12 |
812 | In a reaction ( A+B rightarrow ) products, the rate of reaction is doubled when the concentration of ( A ) is doubled and ( B ) is kept constant and the rate of the reaction is increased by 8 times when the concentrations of both ( A ) and ( B ) are doubled, thus overall order of the reaction is: ( A ) B. 2 ( c cdot 3 ) ( D ) |
12 |
813 | The first order rate constant for the decomposition of ethyl iodide by the reaction ( C_{2} H_{5} I_{(g)} rightarrow C_{2} H_{5(g)}+H I_{(g)} ) at ( 600 K ) is ( 1.60 times 10^{-5} S^{-1} ) Its energy of activation is ( 209 mathrm{kJ} / mathrm{mol} ). Calculate the rate constant of the reaction at ( 700 mathrm{K} ) |
12 |
814 | The order of elementary reactions can be determined by the number of molecules participating in a collision. Based on this knowledge, which of the following is least likely an elementary reaction? A. A unimolecular process such as ( C H_{3} N C rightarrow C H_{3} C N ) B. A bimolecular reaction such as ( N O+O_{3} rightarrow N O_{2}+O_{2} ) C. A tirmolecular process such as ( O+N_{2} O+N rightarrow ) ( N O_{2}+N_{2} ) D. A tetramolecular process such as ( N_{2}+2 H_{2}+C l_{2} rightarrow ) ( 2 N H_{4} C l ) |
12 |
815 | ( ln ) a closed flask of ( 511.0 g H_{2} ) is heated from 300 to 600 K. Which statement is not correct? A. Pressure of the gas increases B. The rate of collisions increases c. The number of moles of gas increases D. The energy of gas molecules increases |
12 |
816 | The reaction ( : 2 A rightarrow 2 B+C ) occurs by the mechanism: ( boldsymbol{A} stackrel{boldsymbol{k}_{1}}{longrightarrow} boldsymbol{B}+boldsymbol{x}(boldsymbol{s} boldsymbol{l} boldsymbol{o} boldsymbol{w}) ) (1) ( boldsymbol{x} stackrel{boldsymbol{k}_{2}}{longrightarrow} boldsymbol{B}+boldsymbol{C}(text {fast}) ) (2) Which of the following step is incorrect? A. molecularity of the reaction is one B. the order of the reaction with respect to A is two C . the rate law is : ( v=k_{1}[A] ) D. ( k_{2}>k_{1} ) |
12 |
817 | What is half life period of a reaction? Calculate the half life period of a first order reaction? |
12 |
818 | Q. 62 All energetically effective collisions do not result in a chemical change. Explain with the help of an example. bet mollisions in which |
12 |
819 | Two substances ( Aleft(t_{frac{1}{2}}=5 min right) ) and ( B ) ( left(t_{frac{1}{2}}=15 mathrm{min}right) ) are taken in such a way that initially ( [boldsymbol{A}]=mathbf{4}[boldsymbol{B}] . ) The time after which both the concentrations will be equal is: A. 5 minutes B. 15 minutes c. 20 minutes D. concentrations can never be equal |
12 |
820 | What is the half-life of a radioactive substance if ( 87.5 % ) of any given amount of the substance disintegrate in 40 minutes? A. 160 min B. 10 min ( c cdot 20 min ) D. 13 min |
12 |
821 | What is average rate of a chemical reaction? |
12 |
822 | Which of the following statements is correct (for zero order reaction)? A. The rate of a reaction decreases with passage of time as the concentration of reactants decreases. B. The rate of a reaction is same at any time during the reaction. C. The rate of a reaction is independent of temperature change. D. The rate of a reaction decreases with increase in concentration of reactant(s). |
12 |
823 | Reaction ( =2 O_{3} rightleftharpoons 3 O_{2} ) Rate ( =boldsymbol{K}left(boldsymbol{O}_{3}right)^{2}left(boldsymbol{O}_{2}right)^{-1} ) Here explain the step of the above rate. |
12 |
824 | For the reaction ( boldsymbol{A}+boldsymbol{B} rightarrow ) product, it is found that the order of ( A ) is 1 and the order of ( B ) is ( frac{1}{2}, ) the concentration of both ( A ) and ( B ) are increased four times, the rate will increase by a factor of ( A cdot 16 ) B. 8 ( c cdot 6 ) D. 4 |
12 |
825 | A piece of wood was found to have ( ^{14} C /^{12} C ) ratio 0.6 times that in a living plant. Calculate the period when the plant died. (Half life of ( ^{14} C=5760 ) years) |
12 |
826 | Which letter shows the potential energy of the products? ( A cdot A ) ( B ) ( c ) ( D ) ( E ) |
12 |
827 | Activation energy ( left(boldsymbol{E}_{boldsymbol{a}}right) ) and rate constants ( left(k_{1} text { and } k_{2}right) ) of a chemical reaction at two different temperature ( T_{1} ) and ( T_{2} ) ) are related by: ( ^{mathbf{A}} cdot ln frac{k_{2}}{k_{1}}=-frac{E_{a}}{R}left[frac{1}{T_{1}}-frac{1}{T_{2}}right] ) в. ( ln frac{k_{2}}{k_{1}}=-frac{E_{a}}{R}left[frac{1}{T_{2}}-frac{1}{T_{1}}right] ) ( ^{mathrm{c}} cdot ln frac{k_{2}}{k_{1}}=-frac{E_{a}}{R}left[frac{1}{T_{2}}+frac{1}{T_{1}}right] ) D ( cdot ln frac{k_{2}}{k_{1}}=frac{E_{a}}{R}left[frac{1}{T_{1}}-frac{1}{T_{2}}right] ) |
12 |
828 | 1 ( m L ) of methyl acetate was added to a flask containing ( 20 m L ) of ( N / 20 H C l ) maintained at ( 25^{circ} mathrm{C} .2 mathrm{m} L ) of the reaction mixture were withdrawn at different intervals and titrated with a standard alkali solution. The following results were obtained: Time ( mathbf{7 5} ) ( mathbf{1 1 9} ) [ (min ) ] ( mathbf{0} ) Alkali [ begin{array}{l} text { used }( \ m L) end{array} quad begin{array}{l} 19.24 \ qquad 24.20 end{array} quad 26.60 ] Show that the reaction follows first order kinetics. |
12 |
829 | A substance which increases the rate of reaction but itself remain chemically unchanged is called a/an: A. substrate B. enzyme c. reactant D. product |
12 |
830 | In the reaction, ( A+B rightarrow ) Products, if ( B ) is taken in excess, then it is an example of : A. second order reaction B. zero order reaction c. fractional order reaction D. first order reaction |
12 |
831 | Which choice below would affect best, the rate of reaction? A. Cool the reaction down B. Add a catalyst c. Decrease the pressure D. Use larger pieces of solid reactants E. Decrease the concentration of the reactants |
12 |
832 | Which of the following statements is not correct? A. For a zero order reaction, ( t_{1 / 2} ) is proportional to initial concentration B. The relationship of variation of rate constant with temperature is given by ( log frac{k_{2}}{k_{1}}=frac{E_{a}}{2.303 R}left[frac{T_{2}-T_{1}}{T_{1} T_{2}}right] ) C. The unit of rate constant for a reaction is ( m o l^{1-n} L^{n-1} s^{-1} ) where ( n ) is order of the reaction D. The unit of rate of reaction changes with order of reaction |
12 |
833 | ( ln operatorname{areaction} 2 H I rightarrow H_{2}+I_{2}, ) the concentration of ( H I ) decreases from 0.5 mol ( L^{-1} ) to 0.4 mol ( L^{-1} ) in 10 minutes.What is the rate of reaction during this interval? A ( .5 times 10^{-3} mathrm{M} min ^{-1} ) B . ( 2.5 times 10^{-3} mathrm{M} ) min( ^{-1} ) c. ( 5 times 10^{-2} M ) min ( ^{-1} ) D. 2.5 ( times 10^{-2} mathrm{M} ) min( ^{-1} ) |
12 |
834 | Two reactions, ( A rightarrow ) Products and ( B rightarrow ) Products, have rate constants ( k_{A} ) and ( k_{B} ) at temperature ( T ) and activation energies ( boldsymbol{E}_{boldsymbol{A}} ) and ( boldsymbol{E}_{boldsymbol{B}} ) respectively. If ( k_{A}>k_{B} ) and ( E_{A}k_{B} ) |
12 |
835 | For the reaction; ( N_{2} O_{5} rightarrow 2 N O_{2}+frac{1}{2} O_{2} ) Given: ( -frac{boldsymbol{d}left[boldsymbol{N}_{2} boldsymbol{O}_{5}right]}{boldsymbol{d} boldsymbol{t}}=boldsymbol{K}_{1}left[boldsymbol{N}_{2} boldsymbol{O}_{5}right], frac{boldsymbol{d}left[boldsymbol{N} boldsymbol{O}_{2}right]}{boldsymbol{d} boldsymbol{t}}= ) ( boldsymbol{K}_{2}left[boldsymbol{N}_{2} boldsymbol{O}_{5}right], frac{boldsymbol{d}left[boldsymbol{O}_{2}right]}{boldsymbol{d} boldsymbol{t}}=boldsymbol{K}_{3}left[boldsymbol{N}_{2} boldsymbol{O}_{5}right] ) The relation between ( boldsymbol{K}_{1}, boldsymbol{K}_{2} ) and ( boldsymbol{K}_{3} ) is: ( mathbf{A} cdot 2 K_{1}=K_{2}=4 K_{3} ) в. ( K_{1}=K_{2}=K_{3} ) ( mathbf{c} cdot 2 K_{1}=4 K_{2}=K_{3} ) D. none of the above |
12 |
836 | On increasing the temperature by ( 10^{0} mathrm{C} ) A. number of collisions get doubled B. value of rate constant does not change C. energy of activation increases D. number of fruitful collisions gets doubled |
12 |
837 | For a given reaction of first order, it takes 20 minutes for the concentration to drop from ( 1.0 mathrm{M} ) to ( 0.6 mathrm{M} ). The time required for the concentration to drop from ( 0.6 ~ M ) to ( 0.36 M ) will be: A. more than 20 minutes B. less than 20 minutes c. equal to 20 minutes D. infinite time |
12 |
838 | Write the order of reaction in which unit of rate and rate constant becomes equal? |
12 |
839 | Which of the following statements are correct? This question has multiple correct options ( A cdot A ) plot of ( log K_{P} ) vs. ( 1 / T ) is linear. B. A plot of log [X] vs. time is linear for I order reaction ( X rightarrow P ) C. A plot of log P vs. 1/T is linear at constant volume. D. A plot of P vs. 1/V is linear at constant temperature. |
12 |
840 | The rate of the zero order reaction; ( boldsymbol{A}+ ) ( B rightarrow C ) follows the rate equation: Rate ( =boldsymbol{k}[boldsymbol{A}]^{0}[boldsymbol{B}]^{0} ) Then the rate of the reaction is: A. dependent on the concentration of reactant B. dependent on the concentration of product c. independent of concentrations of both reactant and product D. none of these |
12 |
841 | O. 24 For a complex reaction ………. (a) order of overall reaction is same as molecularity of the slowest step (b) order of overall reaction is less than the molecularity of the slowest step (c) order of overall reaction is greater than molecularity of the slowest step (d) molecularity of the slowest step is never zero or non-integer |
12 |
842 | The reaction ( boldsymbol{A}(s) rightarrow 2 B(g)+C(g) ) is first order. The pressure after 20 min. and after a very long time are ( 150 mathrm{mm} ) Hg and 225 mm Hg. The value of rate constant and pressure after 40 min are? A. 0.05 In 1.5 min ( ^{-1}, 200 ) mm men B. 0.5 In 2 min ( ^{-1}, 300 ) mm c. 0.05 In 3 min( ^{-1} ), 300 mm D. ( 0.05 operatorname{In} 3 ) min( ^{-1}, 200 mathrm{mm} ) |
12 |
843 | Question 24. Consider a certain reaction; A- products with k=2.0 x 10-2 8-. Calculate the concentration of A remaining after 100 s, if the initial concentration of A is 1.0 mol L. It is a first order reaction so, calculate [A] or (a – x) by using first order integrated equationt = – log k |
12 |
844 | For a zero order reaction, ( boldsymbol{A} longrightarrow boldsymbol{P}, boldsymbol{t}_{1 / 2} ) is: (k is the rate constant, ( [A]_{0} ) is the initial concentration of ( boldsymbol{A} ) ) ( ^{A} cdot frac{[A]_{0}}{2 k} ) B. ( frac{ln 2}{k} ) c. ( frac{1}{k[A]_{0}} ) D. ( frac{ln 2}{[A]_{0} k} ) |
12 |
845 | Consider following two reactions: ( boldsymbol{A} longrightarrow ) Product, ( quad-frac{boldsymbol{d}[boldsymbol{A}]}{boldsymbol{d} boldsymbol{t}}=boldsymbol{k}_{1}[boldsymbol{A}]^{0} ) ( boldsymbol{B} longrightarrow ) Product, ( quad-frac{boldsymbol{d}[boldsymbol{B}]}{boldsymbol{d} boldsymbol{t}}=boldsymbol{k}_{2}[boldsymbol{B}]^{1} ) ( k_{1} ) and ( k_{2} ) are expressed in terms of molarity ( left(operatorname{mol} L^{-1}right) ) and time ( (s) ) as: A ( cdot s^{-1}, M s^{-1} L^{-} ) B. ( M s^{-1}, M s^{-1} ) c. ( s^{-1}, M^{-1} s^{-1} ) D. ( M s^{-1}, s^{-1} ) |
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846 | For a reaction, ( 2 N O(g)+O_{2}(g) rightarrow ) ( mathbf{2} N boldsymbol{O}_{2}(boldsymbol{g}) ) Rate ( =boldsymbol{k}[boldsymbol{N} boldsymbol{O}]^{2}left[boldsymbol{O}_{2}right] ) if the volume of the reaction vessel is doubled, then the rate of the reaction: A. will diminish to ( 1 / 4 ) of initial value B. will diminish to ( 1 / 8 ) of initial value c. will grow 4 times D. will grow 8 times |
12 |
847 | Instantaneous rate of reaction for the reaction ( 3 A+2 B rightarrow 5 C ) is A ( cdot+frac{1}{3} frac{d[A]}{d t}=-frac{1}{2} frac{d[B]}{d t}=+frac{1}{5} frac{d[C]}{d t} ) B. ( -frac{1}{3} frac{d[A]}{d t}=-frac{1}{2} frac{d[B]}{d t}=+frac{1}{5} frac{d[C]}{d t} ) C ( cdot-frac{1}{3} frac{d[A]}{d t}=+frac{1}{2} frac{d[B]}{d t}=-frac{1}{5} frac{d[C]}{d t} ) D. ( +frac{1}{3} frac{d[A]}{d t}=-frac{1}{2} frac{d[B]}{d t}=-frac{1}{5} frac{d[C]}{d t} ) |
12 |
848 | For a reaction ( frac{boldsymbol{d} boldsymbol{X}}{boldsymbol{d} boldsymbol{t}}=boldsymbol{K}left[boldsymbol{H}^{+}right]^{n} . ) If ( boldsymbol{p} boldsymbol{H} ) of reaction medium changes from two to one, the rate becomes 100 times of the value at ( p H=2 . ) The order of reaction is: ( A ) B. 2 ( c cdot 0 ) D. 3 |
12 |
849 | For the reaction, ( boldsymbol{C l}_{2}+mathbf{2} boldsymbol{I}^{-} rightarrow boldsymbol{I}_{2}+ ) ( 2 C l^{-}, ) the initial concentration of ( I^{-} ) was 0.20 mol ( l i t^{-1} ) and the concentration after 20 min was 0.18 mol lit( ^{-1} . ) Then, the rate of formation of ( I_{2} ) in ( operatorname{mol} l i t^{-1} min ^{-1} ) would be: A ( cdot 1 times 10^{-3} ) B . ( 5 times 10^{-4} ) c. ( 1 times 10^{-4} ) D . ( 5 times 10^{-3} ) |
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850 | ( boldsymbol{A}_{(g)} stackrel{Delta}{longrightarrow} boldsymbol{P}_{(g)}+boldsymbol{Q}_{(g)}+boldsymbol{R}_{(g)}, ) follows first order kinetics with a half life of ( 69.3 s ) at ( mathbf{5 0 0} mathrm{K} . ) Starting from the ( operatorname{gas}^{prime} boldsymbol{A}^{prime} ) enclosed in a container at ( 500 mathrm{K} ) and at a pressure of 0.4 atm, the total pressure of the system after ( 230 s ) will be: A. 1.32 atm B. 1.12 atm c. 1.15 atm D. 1.22 atm |
12 |
851 | What is the half life of a radioactive substance if ( 75 % ) of its given amount disintegrate in 60 min? A . 30 min B. 45 min ( c .75 ) min D. 90 min |
12 |
852 | Rate of substitution reaction in phenol is: A. slower then the rate of benzene B. faster than the rate of benzene c. equal to the rate of benzene D. none of these |
12 |
853 | Decomposition of ozone shows negative order with respect to oxygen. A. True B. False |
12 |
854 | Units of instantaneous rate of reaction is equal to : A. an overall rate of reaction B. an average rate of reaction c. Both ( A ) and ( B ) D. unitless |
12 |
855 | What is the order of a reaction which has a rate expression rate( = ) ( boldsymbol{k}[boldsymbol{A}]^{frac{3}{2}}[boldsymbol{B}]^{-1} ? ) A ( .3 / 2 ) в. ( 1 / 2 ) c. 0 D. None of the above |
12 |
856 | Which among the following reactions is an example of instantaneous reaction under normal condition? A ( .2 H_{2}+O_{2} rightarrow 2 H_{2} O ) в. ( N_{2}+O_{2} rightarrow 2 N O ) c. ( N a O H+H C l rightarrow N a C l+H_{2} O ) D. ( C_{12} H_{22} O_{11}+H_{2} O rightarrow C_{6} H_{12} O_{6}+C_{6} H_{12} O_{6} ) |
12 |
857 | The reaction is given below, the rate constant for disappearance of A is ( 7.48 times 10^{-3} )sec( ^{-1} ). The time required for the total pressure in a system containing ( A ) at an initial pressure of 0.1 atm to rise to 0.145 atm is: ( mathbf{2} boldsymbol{A}(boldsymbol{g}) rightarrow mathbf{4} boldsymbol{B}(boldsymbol{g})+boldsymbol{C}(boldsymbol{g}) ) A. 0.80 min B. 0.567 min c. 0.433 min D. 0.344 min |
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858 | For a reaction ( boldsymbol{R} rightarrow boldsymbol{P} ), the concentration of a reactant changes from ( 0.05 M ) to ( 0.04 M ) in 30 minutes. What will be the average rate of reaction in minutes? A ( cdot 4 times 10^{-4} mathrm{M} min ^{-1} ) В. ( 8 times 10^{-4} mathrm{M} min ^{-1} ) ( mathrm{c} cdot 3.3 times 10^{-4} mathrm{M} min ^{-1} ) D. 2.2 ( times 10^{-4} mathrm{M} ) min( ^{-1} ) |
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859 | ( 2 K C l O_{3} rightarrow 2 K C l+3 O_{2} . ) What will be the instantaneous rate of the reaction in terms of the reactant? A ( cdot frac{1}{2} frac{dleft[K C l O_{3}right]}{d t} ) в. ( -frac{1}{2} frac{dleft[K C l O_{3}right]}{d t} ) c. ( frac{dleft[K C l O_{3}right]}{d t} ) D. ( -frac{dleft[K C l O_{3}right]}{d t} ) |
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860 | After how many seconds will the concentration of a reactant in a reaction is halved in a first order reaction, if the rate constant is ( 6.93 times 10^{-3} s e c^{-1} ) A ( cdot 10^{4} ) B. 100 ( c cdot 10^{3} ) D. 10 |
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861 | Which statement about molecularity of reaction is not correct? A. It can be obtained from reaction mechanism B. It may be either whole number or fractional C. It depends on elementary step of reaction D. It is the number of molecules of reactants taking part in a single step reaction |
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862 | For a reaction ( 2 A+3 B rightarrow ) Products the rate law expression is given by rate ( =K(A)^{1}(B)^{2} . ) The order of the reaction with respect to ( A, B ) and overall order of reaction are: ( mathbf{A} cdot 2,1,3 ) в. 1,2,3 c. 0,1,2 D. 2,1,0 |
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863 | An endothermic reaction ( A rightarrow B ) have an activation energy 15 kcal/mol and the heat of reaction is 5 kcal/mol. The activation energy of the reaction ( boldsymbol{B} rightarrow ) ( boldsymbol{A} ) is: A . 20 kcal/mol B. 15 kcal/mol c. 10 kcal/mol D. zero |
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864 | Rate constant (K) of a first order reaction is ( 5.5 times 10^{-14} s e c^{-1} . ) Find the half life of reaction. |
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865 | For the reaction ( 4 N H_{3}+5 O_{2} rightarrow ) ( 4 N O+6 H_{2} O, ) if the rate of disappearance of ( N H_{3} ) is ( 3.6 times ) ( 10^{-3} ) mol ( L^{-1} s^{-1}, ) what is the rate of formation of ( boldsymbol{H}_{2} boldsymbol{O} ) ? A ( cdot 5.4 times 10^{-3} ) mol ( L^{-1} s^{-1} ) B. ( 3.6 times 10^{-3} ) mol ( L^{-1} s^{-1} ) D. ( 0.6 times 10^{-4} ) mol ( L^{-1} s^{-1} ) |
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866 | Q Type your question ( left(frac{a x}{d t}right) ) is plotted against ( log [A], ) then the graph is of the type: ( A ) B. ( c ) ( D ) |
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867 | For the elementary reaction ( 2 S O_{2(g)}+ ) ( O_{2(g)} rightarrow 2 S O_{3(g)}, ) identify the correct among the following relaitons. A ( cdot frac{-dleft[S O_{2(g)}right]}{d t}=frac{-dleft[O_{2(g)}right]}{d t} ) ( ^{mathbf{B}} cdot frac{+1}{2} frac{dleft[S O_{3(g)}right]}{d t}=frac{dleft[S O_{2(g)}right]}{d t} ) c. ( frac{+dleft[S O_{3(g)}right]}{d t}=frac{-2 dleft[O_{2(g)}right]}{d t} ) D. ( frac{+dleft[S O_{2(g)}right]}{d t}=frac{-dleft[O_{2(g)}right]}{d t} ) |
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868 | A certain reaction occurs in the following steps. (i) ( C l_{(g)}+O_{3(g)} rightarrow C l O_{(g)}+O_{2(g)} ) (ii) ( C l O_{(g)}+O_{(g)} rightarrow C l_{g}+O_{2(g)} ) What is the molecularity of each of the elementary steps? |
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869 | Question 2. In a reaction, 2A – products, the concentration of A decreases from 0.5 mol L to 0.4 mol L in 10 min. Calculate the rate during this interval. |
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870 | The rate of a reaction quadruples when the temperature changes from 300 to 310K. What is the activation energy of this reaction? (Assume activation energy and preexponential factor are independent of temperature ; ( ln 2=0.693 ; mathrm{R}=8.314 ) ( left.boldsymbol{m o l}^{-1} boldsymbol{K}^{-1}right) ) |
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871 | Which of the following isomerization reactions is/are of the first order? This question has multiple correct options A. Cyclopropane ( rightarrow ) Propane B. cis-But-2-ene ( rightarrow ) Trans-but-2-ene c. vinyl allyl ether ( rightarrow ) Pent-4-enal D. ( C H_{4} N C rightarrow C H_{3} C N ) |
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872 | 30 Question 8. In a pseudo first order hydrolysis of ester in water, the following results were obtained : 60 90 [Ester]/moll 0.55 0.31 0.17 0.085 () Calculate the average rate of reaction between the time interval 30 to 60 s. (i) Calculate the pseudo first order rate constant for the hydrolysis of ester. Calculate average rate from the relation, Average rate = Change in concentration / Time taken 2.303, [A] ( = log Find at different time intervals and then calculate the average ! |
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873 | In a catalytic conversion of ( N_{2} ) to ( N H_{3} ) by Haber’s process, the rate of reaction was expressed as change in the concentration of ammonia per time is ( 40 times 10^{-3} mathrm{mol} mathrm{L}^{-1} mathrm{s}^{-1} . ) If there is no side reaction, the rate of the reaction as expressed in terms of hydrogen is : ( left(text { in } operatorname{mol} L^{-1} s^{-1}right) ) A ( cdot 60 times 10^{-3} ) B . ( 20 times 10^{-3} ) c. 1.200 D. ( 10.3 times 10^{-3} ) |
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874 | The term ( frac{d c}{d t} ) in a rate equation refers to: A. concentration of reactants B. change in concentration of reactants or products with time C. velocity constant of the reaction D. concentration of products |
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875 | Consider the following elementary reaction, [ mathbf{2 A}+boldsymbol{B}+boldsymbol{C} rightarrow boldsymbol{text {Products.}} ] All reactant are present in the gaseous state and reactant ( C ) is taken in excess. What is the rate expression of the reaction? ( mathbf{A} cdot ) Rate( =k[A]^{2}[B][C] ) B . Rate( =k[A]^{2}[B] ) ( c ) [ text {Rate}=k frac{[A]^{2}[B]}{[C]} ] D. Rate( =k[C]^{0} ) |
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876 | Write four differences between molecularity and order of reaction. |
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877 | What will be the initial rate of reaction, if its rate constant is ( 10^{-3} ) min ( ^{-1} ) and the concentration of reactant is ( 0.2- ) ( d m^{-3} ? ) How much of reactant will be converted into product in 200 minutes? |
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878 | Calculate the order of reaction from the following data: [ begin{array}{l} qquad mathbf{2} N boldsymbol{H}_{3} rightarrow boldsymbol{N}_{2}+mathbf{3} boldsymbol{H}_{2} text { (reaction) } \ text { Pressure }(mathbf{m m} mathrm{Hg}) quad mathbf{5 0} quad 100 quad 200 \ text { Half lives }(min ) quad text { 3.52 } quad 1.82 quad 0.93 end{array} ] |
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879 | Question 28. The decomposition of A into product has values of K as 45x 103 -1 at 10°C and energy of activation 60 kJ mol”. At what temperature would K be 1.5x 10* s-1. Find T, by putting values of other quantities in the Arrhenius equation 100K2 – E 12-T log=2303RTATZ |
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880 | Explain: The molecules during collisions attain threshold energy and only then they result in chemical reaction. Certain collisions inspite of possessing thr es hold energy do not result in chemical reactions. This is because the orientation of collisions is not suitable for a chemical reaction. Thus, the collisions which are associated with threshold energy and proper orientation only result in chemical reaction. |
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881 | The rate of reaction increase by the increase of temperature because: A. collision frequency is increased. B. energy of products decreases. C. the fraction of molecules possessing energy ( geq E_{T} ) (threshold energy) increases. D. mechanism of a reaction is changed. |
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882 | ( frac{3}{4} ) part of radioactive compound undergoes decay in 2h. Calculate its half-life time. A. 60 min B. 45 min ( c .30 ) min D. 15 min |
12 |
883 | For the following reaction ( left(boldsymbol{C} boldsymbol{H}_{3}right)_{3} boldsymbol{C C l}+boldsymbol{H}_{2} boldsymbol{O} rightarrow ) ( left(boldsymbol{C} boldsymbol{H}_{3}right)_{3} boldsymbol{C O H}+boldsymbol{H} boldsymbol{C l}left(frac{d boldsymbol{x}}{d t}right)= ) ( boldsymbol{k}left[left(boldsymbol{C} boldsymbol{H}_{3}right)_{3} boldsymbol{C C l}right] ) the rate determining step is: A ( cdotleft(C H_{3}right)_{3} C C l rightarrowleft(C H_{3}right)_{3} C oplus+C l ) B . ( left(C H_{3}right)_{3} C C l+H_{2} O rightarrowleft(C H_{3}right)_{3} C O H+H C l ) C. ( left(C H_{3}right)_{3} C oplus+H_{2} O rightarrowleft(C H_{3}right)_{3} C O H+H^{+} ) D. ( H^{+}+C l^{-} rightarrow H C l ) |
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884 | Q. 2 In the presence of a catalyst, the heat evol sence of a catalyst, the heat evolved or absorbed during the reaction (a) increases (b) decreases (c) remains unchanged (d) may increase or decrease |
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885 | The rate of a chemical reaction doubles for every ( 10^{circ} mathrm{C} ) rise in temperature. If the temp is increased by ( 60^{circ} mathrm{C} ) the rate of reaction increases by: A. 20 times B. 32 times c. 64 times D. 128 times |
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886 | In a particular process, the concentration of a solution that is initially 0.24 M is reduced to 0.12 M in 10 hr and ( 0.06 mathrm{M} ) in ( 20 mathrm{hr} ) ( 6.93 times 10^{-x} h r^{-1} ) is the rate constant for the reaction? value of ( x ) is |
12 |
887 | Define pseudio first order reaction Show that half life of zero order reaction is directly proportional to concentration of reactant. |
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888 | The thermal decomposition of a molecule shows first order kinetics. The molecule decomposes ( 50 % ) in 120 min. How much time it will take to decompose ( 90 % ? ) A. 300 min B . 360 min c. 398.8 min D. 400 min |
12 |
889 | The rate of the first order reaction, ( A longrightarrow ) Products, is ( 7.5 times 10^{-4} ) mol ( L^{-1} s^{-1}, ) when the concentration of ( A ) is 0.2 mol ( L^{-1} . ) The rate constant of the reaction is: A ( cdot 2.5 times 10^{-5} s^{-1} ) в. ( 8.0 times 10^{-4} s^{-1} ) D. ( 3.75 times 10^{-3} s^{-1} ) |
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890 | For the reaction; ( mathbf{4} boldsymbol{N} boldsymbol{H}_{boldsymbol{3}(boldsymbol{g})}+mathbf{5} boldsymbol{O}_{boldsymbol{2}(boldsymbol{g})} rightarrow ) ( 4 N O_{(g)}+6 H_{2} O_{(g)}, ) the rate of reaction in terms of disappearance of ( N H_{3} ) is ( -frac{boldsymbol{d}left[boldsymbol{N} boldsymbol{H}_{3}right]}{boldsymbol{d} t}, ) then write the rate expression in terms of concentration of ( O_{2}, N O ) and ( H_{2} O ) |
12 |
891 | At ( 27^{circ} mathrm{C} ) it was observed in the hydrogenation of a reaction, the pressure of ( boldsymbol{H}_{2}(boldsymbol{g}) ) decreases from 10 atm to 2 atm in 10 min. Calculate the rate of reaction in ( mathrm{M} ) min( ^{-1} ) (Given ( mathrm{R}= ) ( left.0.08 L operatorname{atm} K^{-1} m o l^{-1}right) ) A. 0.02 2 B. 0.03 ( c .0 .04 ) D. 0.05 |
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892 | Consider the following reaction: ( boldsymbol{H}_{2}(boldsymbol{g})+boldsymbol{I}_{2}(boldsymbol{g}) rightarrow boldsymbol{2} boldsymbol{H} boldsymbol{I}(boldsymbol{g})= ) ( boldsymbol{k}left[boldsymbol{H}_{2}right]left[boldsymbol{I}_{2}right] ) Which one of the following statements is correct? A. The reaction must occur in a single step B. This is a second order reaction overal c. Raising the temperature will cause the value of ( k ) to decrease D. Raising the temperature lowers the activation energy for the reaction |
12 |
893 | For the reaction ( 2 A+3 B rightarrow ) products, ( A ) is taken in excess and on changing the concentration of ( mathrm{B} ) from ( 0.1 mathrm{M} ) to 0.4 M, the rate becomes doubled. Thus, the rate law of the reaction is: A ( cdot frac{d x}{d t}=k[A]^{2}[B]^{2} ) в. ( frac{d x}{d t}=k[A][B] ) ( stackrel{d x}{d t}=k[A]^{0}[B]^{2} ) D. ( frac{d x}{d t}=k[B]^{1 / 2} ) |
12 |
894 | Which statement is true for a liquid/gas mixture at equilibrium? A. The equilibrium constant is dependent on temperature B. The amount of the gas present at equilibrium is independent of pressure C. All interchange between the liquid and gas phases has ceased D. All of the above E. None of the above |
12 |
895 | toppr ( E ) Q Type your question The graph between ( frac{mathrm{i}}{boldsymbol{d t}} ) and time will be of the type: B. ( c ) ( D ) |
12 |
896 | The decomposition of ( C l_{2} O_{7} ) at ( 400 K ) in the gas phase to ( C l_{2} ) and ( O_{2} ) is a first order reaction. (i) After 55 seconds at ( 400 K ), the pressure of ( boldsymbol{C l}_{2} boldsymbol{O}_{7} ) falls from ( mathbf{0 . 0 6 2} ) to 0.044 at ( m . ) Calculate the rate constant. (ii) Calculate the pressure of ( C l_{2} O_{7} ) after 100 seconds of decomposition at this temperature. |
12 |
897 | What does the exponential factor represent? A. The total number of reactants in a reaction. B. The amount of energy needed to start a chemical reaction. C. The fraction of reactants that have approached the activation energy hill and made it over per number of attempts. D. The fraction of reaction energy given off per unit of time. E. The fraction of products that have approached the activation energy hill and made it over per number of attempts. |
12 |
898 | In the reaction between ( N O ) and ( H_{2} ) the following data are obtained Experiment ( 1: P_{H_{2}}= ) constant [ (mathrm{mm} text { of } mathrm{Hg}) quad text { 359 } quad text { 300 } ] ( -frac{P_{H_{2}}}{d t} ) 1.50 ( quad 1.03 quad ) 0.25 Experiment ( 2: P_{N O}= ) constant [ boldsymbol{P}_{H_{2}}(mathrm{mm} text { of } mathrm{Hg}) quad 289 quad 205 ] ( -frac{P_{H_{2}}}{d t} ) ( 1.60 quad 1.10 ) The orders with respect of ( boldsymbol{H}_{2} ) and ( boldsymbol{N} boldsymbol{O} ) are: A ( cdot 1 ) with respect to ( N O ) and 2 with respect to ( H_{2} ) B. 2 with respect to ( N O ) and 1 with respect to ( H_{2} ) c. 1 with respect to ( N O ) and 3 with respect to ( H_{2} ) D. 2 with respect to ( N O ) and 2 with respect to ( H_{2} ) |
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899 | In pseudo unimolecule reactions: A. both the reactants are present in low concentration B. Both the reactants are present in same concentration C. One of the reactant is present in excess D. One of the reactant is non-reactive |
12 |
900 | Ethylene is produced by, ( C_{4} H_{8} stackrel{Delta}{longrightarrow} ) ( 2 C_{2} H_{4} . ) The constant is ( 2.48 times ) ( 10^{-4} )sec( ^{-1} ). Time in hours (nearest integer) in which the molar ratio of the ethylene to cyclobutane in reaction mixture will attain the value of 100 is |
12 |
901 | The reaction, ( boldsymbol{A}+boldsymbol{O} boldsymbol{H}^{-} rightarrow ) Products obeys rate law expression as: ( frac{-boldsymbol{d}[boldsymbol{A}]}{boldsymbol{d} boldsymbol{t}}=boldsymbol{k}[boldsymbol{A}]left[boldsymbol{O H}^{-}right] ) If initial concentrations of ( [A] ) and ( left[boldsymbol{O} boldsymbol{H}^{-}right] ) are ( boldsymbol{0 . 0 0 2} boldsymbol{M} ) and ( boldsymbol{0 . 3} boldsymbol{M} ) respectively and if it take 30 sec for ( 1 % ) ( A ) to react at ( 25^{circ} mathrm{C} ), calculate the rate constant for the reaction. |
12 |
902 | If the half life period for a first order reaction is 69.3 seconds, what is the value of its rate constant? |
12 |
903 | The rate law of reaction between the substance ( boldsymbol{A} ) and ( boldsymbol{B} ) is given by ( boldsymbol{r} boldsymbol{a} boldsymbol{t} boldsymbol{e}= ) ( boldsymbol{K}[boldsymbol{A}]^{n}[boldsymbol{B}]^{m} . ) On doubling the concentration of ( boldsymbol{A} ) and making the volume of ( B ) half the ratio of new rate to the earlier rate of reaction will be: A ( cdot frac{1}{2^{n+m}} ) в. ( m+n ) ( mathbf{c} cdot 2^{n+m} ) D. ( 2^{n-m-m-m} ) |
12 |
904 | ( boldsymbol{A} rightarrow boldsymbol{B} ) The reaction rate for the above reaction is: ( ^{mathbf{A}} cdot frac{d[A]}{d t} ) в. ( -frac{d[B]}{d t} ) c. ( -frac{d t}{d[A]} ) D. ( -frac{d[A B]}{d t} ) |
12 |
905 | ( ln ) a reaction ( boldsymbol{A} longrightarrow boldsymbol{B}+boldsymbol{C}, ) The following data were obtained: t in seconds ( begin{array}{lll}0 & 900 & 1800end{array} ) conc. of ( mathbf{A} ) [ begin{array}{lll} 50.8 & 19.7 & 7.62 end{array} ] Prove that it is a first order reaction. |
12 |
906 | A first order reaction takes 40 min for ( 30 % ) decompsoition. The value of ( t_{1 / 2} ) will be: A. ( 97.7 mathrm{min} ) B. 77.7 min c. ( 80.5 mathrm{min} ) D. ( 70.7 mathrm{min} ) |
12 |
907 | Rate of formation of ( S O_{3} ) in the following reaction ( 2 S O_{2}+O_{2} longrightarrow ) ( 2 S O_{3} ) is ( 100 g quad ) min ( ^{-1} . ) Hence disappearance of ( boldsymbol{O}_{2} ) is: ( begin{array}{ll}text { A. } 50 g & min ^{-1}end{array} ) B. ( 40 g ) min( ^{-1} ) c. ( 200 g ) min( ^{-1} ) D. ( 20 g ) min( ^{-1} ) |
12 |
908 | In the chemical reaction ( boldsymbol{P}+boldsymbol{Q} rightarrow boldsymbol{P} boldsymbol{Q} ) if the concentration of ( P ) and ( Q ) are increased by two fold, the reaction rate: A. decreases to half B. increased by two fold c. increased by eight fold D. increased by four fold |
12 |
909 | The rate of the reaction starting with initial concentrations ( 2 times 10^{3} M ) and ( 1 times 10^{3} M ) are equal to ( 2.40 times ) ( 10^{4} M s^{1} ) and ( 0.60 times 10^{4} M s^{1} ) respectively. Calculate the order of reaction with respect to reactant: |
12 |
910 | The rate for the reaction between ionic compounds cannot be determined because they are generally: A. immeasurably slow reactions B. moderately slow reactions c. instantaneous reactions D. not precipitation reaction |
12 |
911 | Select the incorrect statement(s): A. An activated complex is a high-energy, unstable, short lived configuration of reactant atoms B. An endothermic reaction always has a greater activation energy and a slower rate than the opposing exothermic reaction C. Threshold energy level decreases on heating the reaction mixture D. The geometrical shape and the collision geometry of reacting molecules affects reaction rate |
12 |
912 | Give the unit of rate of reaction. A. Molar B. Second c. Second/molar D. Molar/second |
12 |
913 | For a first order reaction, the half life is independent of: This question has multiple correct options A . initial concentration B. cube root of initial concentration c. first power of final concentration D. square root of final concentration |
12 |
914 | The energy diagram of a reaction ( boldsymbol{P}+ ) ( Q rightarrow R+S ) is given.What are ( A ) and ( B ) in the graph? A. ( A rightarrow ) activation energy, ( B rightarrow ) heat of reaction B. ( A rightarrow ) threshold energy, ( B rightarrow ) heat of reaction C. ( A rightarrow ) heat of energy, ( B rightarrow ) activation reaction D. ( A rightarrow ) potential energy, ( B rightarrow ) energy of reaction |
12 |
915 | What is pseudo first order reaction? Give one example of it. |
12 |
916 | What is the activation energy for the reverse of this reaction? ( N_{2} O_{4}(g) longrightarrow 2 N O_{2}(g) ) Data for the given reaction is: ( Delta boldsymbol{H}= ) ( +54 k J ) and ( E_{f}=+57.2 k J ) A ( .-54 k J ) в. ( +3.2 k J ) ( mathbf{c} .+60.2 k J ) D. ( +111.2 k J ) |
12 |
917 | Rate constant of a reaction is 175 litre ( ^{-2} ) mol ( ^{-2} ) sec ( ^{-1} ). What is the order of reaction? A. First B. Second c. Third D. zero |
12 |
918 | The reaction ( : boldsymbol{X} rightarrow ) product, follows first-order kinetics in 20 minutes, the concentration of ( boldsymbol{X} ) changes from ( mathbf{0 . 1} boldsymbol{M} ) to ( 0.05 M ) then rate of reaction when concentration of ( boldsymbol{X} ) is ( mathbf{0 . 0 2} boldsymbol{m o l} / boldsymbol{L} ) is: A. ( 1.73 times 10^{-4} mathrm{M} / min ) B. ( 3.47 times 10^{-5} mathrm{M} / mathrm{min} ) c. ( 6.94 times 10^{-4} mathrm{M} / min ) D. ( 1.73 times 10^{-5} mathrm{M} / mathrm{min} ) |
12 |
919 | For a reaction ( 2 A+B rightarrow C+D, ) the active mass of ( B ) is kept constant but that of ( boldsymbol{A} ) is tripled. The rate of reaction will – A. Decrease by 3 times B. Increased by 9 times C. Increase by 3 times D. Unpredictable |
12 |
920 | Consider the three statements about reaction energy diagrams and the relative magnitudes of the activation energy, ( E_{a}, ) and the enthalpy of reaction, ( Delta boldsymbol{H} ) One or more of the statements is true. Identify the correct statement or combination of statements from the four choices below. Statement For an endothermic reaction, the magnitude of ( E_{a} ) is always greater than ( triangle H ) For an exothermic reaction, the magnitude of |
12 |
921 | Trans-1,2-dideuterocyclopropane ( (boldsymbol{A}) ) undergoes a first-order decomposition. The observed rate constant at a certain temperature measured in terms of disappearance of ‘ ( boldsymbol{A} ) ‘ has ( 1.52 times ) ( 10^{-4} s e c^{-1} . ) Analysis of products showed that the reaction followed two parallel paths, one leading to dideuteropropane ( (B) ) and the other to cis- 1,2 dideuterocyclopropane ( (C) .(B) ) was found to constitute ( 11.2 % ) of the reaction product, independently of the extent of reaction. What is the order of reaction for each path and what is the value of the rate constant for the formation of each of the products? |
12 |
922 | ( mathbf{2} boldsymbol{A}+boldsymbol{B} rightarrow boldsymbol{C}+boldsymbol{D} ) In this reaction, if we double the concentration of ( A, ) reaction rate become two times. And in another experiment, we double the concentration of ( A ) and ( B ), reaction rate again become two times. What is the order of this reaction? A B. 3 ( c cdot 2 ) D. 1.5 |
12 |
923 | Q. 41 For a zero order reaction will the molecularity be equal will the molecularity be equal to zero? Explain. the number of |
12 |
924 | Which of the following statements is/are false? This question has multiple correct options A. A fast reaction has a large rate constant and short half-life B. Half life depends on concentration of reactants for first order reaction. C. For a first order reaction, the half-life is independent of concentration D. The half-life of a reaction is half the time required for the reaction to go to completion |
12 |
925 | If we plot a graph between ( log _{10} k ) and ( frac{1}{T} ) by Arrhenius equation, the slope is: A ( .-E_{a} / R ) в. ( +E_{a} / R ) c. ( -frac{E_{a}}{2.303 R} ) D. ( +frac{E_{a}}{2.303 R} ) |
12 |
926 | Show that in a first order reaction, time required for completion of ( 75 % ) is twice of half life of the reaction. ( (log 2= ) ( mathbf{0 . 3 0 1 0} ) |
12 |
927 | Which of the following is/are examples of pseudo unimolecular reactions? This question has multiple correct options ( mathbf{A} cdot C H_{3} C O_{2} C_{2} H_{5}+H_{2} O stackrel{H}{rightarrow} C H_{3} C O_{2} H+C_{2} H_{5} O H ) ( ^{mathbf{B}} cdot C_{12} H_{22} O_{11}+H_{2} O stackrel{H}{rightarrow}^{oplus} quad begin{array}{ll}C_{6} H_{12} O_{6} & =C_{6} H_{12} O_{6} \ & (G l u operatorname{cose})end{array}=quad(text {Fructose}) ) ( mathbf{c} cdot C H_{3} C O C l+H_{2} O rightarrow C H_{3} C O_{2} H+H C l ) ( mathrm{D} cdot mathrm{CH}_{3} mathrm{CO}_{2} mathrm{C}_{2} mathrm{H}_{5}+mathrm{H}_{2} mathrm{O} stackrel{mathrm{OH}}{rightarrow} mathrm{CH}_{3} mathrm{CO}_{2} mathrm{H}+mathrm{C}_{2} mathrm{H}_{5} mathrm{OH} ) |
12 |
928 | The half year period for a zero order reaction is equal to: ( mathbf{A} cdot 2 K /[A] o ) в. ( frac{[A]_{0}}{2 k} ) c. ( frac{0.693}{k} ) D. ( frac{0.693}{k[A]_{o}} ) |
12 |
929 | Rate constant K varies with temperature by equation [ log Kleft(m i n^{-1}right)=log 5- ] ( frac{2000}{R T quad X quad 2.303} ) we can conclude that? A. Pre-exponential factor A is ( 10^{5} ) B . ( E_{a} ) IS ( 2000 mathrm{K} ) cal C. ( E_{a} ) is ( 9.12 mathrm{K} ) cal D. The pre-exponential factor A is 5 |
12 |
930 | Calculate the overall order of a reaction which has the rate expression (a) Rate ( =boldsymbol{k}[boldsymbol{A}]^{1 / 2}[boldsymbol{B}]^{3 / 2} ) (b) Rate ( =boldsymbol{k}[boldsymbol{A}]^{3 / 2}[boldsymbol{B}]^{-1} ) |
12 |
931 | The minus ( operatorname{sign} ) in ( r a t e=-frac{d[A]}{d t} ) indicates the concentration of the time. The rate of a reaction is always quantity. The rate of reaction increases with concentration of reactants. The blanks in the question corresponds to: A. decrease, products, positive, increase B. increase, reactants, negative, decrease c. decrease, reactants, positive, increase D. increase, products, positive, increase |
12 |
932 | Chemical kinetics a branch of physical chemistry deals with: A. structure of molecules B. heat changes in a reaction c. physical changes in a reaction D. rate of reactions |
12 |
933 | Assertion Formation of ( boldsymbol{H} boldsymbol{I} ) is a bimolecular reaction Reason Two molecules of reactants are involved in this reaction. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct, but Reason is not the correct explanation for Assertion C. Assertion is correct, but Reason is incorrect D. Assertion is incorrect, but Reason is correct |
12 |
934 | The time required for the decomposition of ( N_{2} O_{5}, ) so that the total pressure becomes 0.15 atm is (Given ( log 1.8=0.255) ) A . ( 25.5 mathrm{sec} ) B. 35.5 sec c. ( 45.5 mathrm{sec} ) D. ( 55.5 mathrm{sec} ) |
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935 | Two reactions proceed at ( 25^{circ} mathrm{C} ) at the same rate; the temperatue coefficient of the rate of the first reaction is 2 and that of the second reaction is ( 2.5 . ) Find the ratio of rate of these reactions at ( 95^{circ} C ) |
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936 | ( 2 S O_{2}+O_{2} rightarrow 2 S O_{3} ) Rate of formation of ( boldsymbol{S} boldsymbol{O}_{3} ) according to the reaction is ( 1.6 times 10^{-3} mathrm{kg} ) min ( ^{-1} ) Hence rate at which ( S O_{2} ) reacts is: A ( cdot 1.6 times 10^{-3} mathrm{kg} min ^{-1} ) B. ( 8.0 times 10^{-4} mathrm{kg} min ^{-1} ) c. ( 3.2 times 10^{-3} mathrm{kg} min ^{-1} ) D. ( 1.28 times 10^{-3} ) kg ( min ^{-1} ) |
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937 | What is psuedo first order reaction? Give an example. | 12 |
938 | The decomposition of ( N_{2} O_{5} ) dissolved in carbon tetra chloride occurs followingly at constant temperature. ( N_{2} O_{5(s o l u t i o n)} rightleftharpoons 2 N O_{2(s o l u t i o n)}+ ) ( frac{1}{2} O_{2(g)} ) This reaction is of first order and its rate constant is ( 5 times 10^{-4} mathrm{sec}^{-1} ? ) If initial concentration of ( N_{2} O_{5} ) is 0.4 mol litre then (i) What will be the initial reaction rate? (ii) What will be the half-life period of this reaction? (iii) What time will be taken to complete ( 75 % ) reaction? |
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939 | In the following first-order competing reactions: ( A+ ) Reagent ( longrightarrow ) Product; ( quad B+ ) Reagent ( longrightarrow ) Product The ratio of ( frac{boldsymbol{K}_{1}}{boldsymbol{K}_{2}} ) if only ( 50 % ) of ( mathrm{B} ) will have been reacted when ( 94 % ) of ( A ) has been reacted is: (as nearest integer) |
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940 | At ( 380^{circ} C, ) the half life period for the first order decomposition of ( boldsymbol{H}_{2} boldsymbol{O}_{2} ) is ( boldsymbol{3} boldsymbol{6} boldsymbol{0} ) min. The energy of activation of the reaction is ( 200 k J ) mol ( ^{-1} ). Calculate the time required for ( 75 % ) decomposition at ( 450^{circ} mathrm{C} ) |
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941 | For the reaction, ( boldsymbol{H}_{2}(boldsymbol{g})+boldsymbol{B} boldsymbol{r}_{2}(boldsymbol{g}) rightarrow ) ( 2 H B r(g), ) then reaction rate( = ) ( boldsymbol{K}left[boldsymbol{H}_{2}right]left[boldsymbol{B} boldsymbol{r}_{2}right]^{1 / 2} . ) Which statement is true about this reaction: A. The reaction is of second order B. Molecularity of the reaction is ( 3 / 2 ) c. The unit of ( k ) is sec ( ^{-1} ) D. Molecularity of the reaction is 2 |
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942 | Here is another look at the reaction of crystal violet with sodium hydroxide, a first-order reaction ( (ln A mathbf{v} text { time }) ) What is the significance of the slope? |
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943 | Find the values of ( A, B ) and ( C ) in the following table for the reaction ( X+ ) ( boldsymbol{Y} rightarrow Z . ) The reaction is of first order w.r.t ( X ) and zero w.r.t. ( Y ) Exp. ( [boldsymbol{X}]left(boldsymbol{m o l} boldsymbol{L}^{-1}right) quad[boldsymbol{Y}]left(boldsymbol{m o l} boldsymbol{L}^{-1}right) ) 1 2 begin{tabular}{ccc} 0.1 & 0.1 \ ( A ) & 0.2 \ 0.4 & 0.4 \ ( C ) & 0.2 \ hline end{tabular} 3 4 ( mathbf{A} cdot A=0.2 mathrm{mol} L^{-1}, B=8 times 10^{-2} mathrm{mol} L^{-1} mathrm{s}^{-1}, C= ) ( 0.1 mathrm{mol} L^{-1} ) B . ( A=0.4 ) mol ( L^{-1}, B=4 times 10^{-2} ) mol ( L^{-1} s^{-1}, C= ) ( 0.2 mathrm{mol} L^{-1} ) C ( . A=0.2 ) mol ( L^{-1}, B=2 times 10^{-2} ) mol ( L^{-1} s^{-1}, C= ) ( 0.4 mathrm{mol} L^{-1} ) D. ( A=0.4 ) mol ( L^{-1}, B=2 times 10^{-2} ) mol ( L^{-1} s^{-1}, C= ) ( 0.4 mathrm{mol} L^{-1} ) |
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944 | For the inversion of cane sugar ( left(C_{12} H_{22} O_{11}right) ) obeying I order following data were obtained. Time (min.) ( mathbf{0} ) rotation of Angle of +20 2.5 solution(degree) What will be rate constant in ( m i n^{-1} ? ) [ (ln 2=0.7) ] A. 0.7 B. 0.14 c. 0.21 D. 0.07 |
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945 | Which of the following is wrong? A. order of the reaction is negative, positive or fractional B. molecularity of the reaction is always equal to the sum of stoichiometric co-efficients. C. the order of a reaction may be zero D. half life is independent of the concentration of reactants in first order reaction |
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946 | A chemical reaction was carried out at ( 300 mathrm{K} ) and ( 280 mathrm{K} ). The rate constants were found to be ( K_{1} ) and ( K_{2} ) at ( 300 mathrm{K} ) and ( 280 mathrm{K} ) respectively. Then which of the following is true? A. ( K_{1}=4 K_{1} ) B . ( K_{2}=2 K_{1} ) c. ( K_{2}=0.25 K_{1} ) D. ( K_{2}=0.5 K_{1} ) |
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947 | Which curve corresponds to the temperature dependence of the rate ( boldsymbol{R} ) of a simple one step reaction? ( A ) в. c. D. None of the above |
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948 | Derive the relation between half life and rate constant for a first order reaction. |
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949 | For the reaction: ( left[C rleft(H_{2} Oright)_{6}right]^{3+}+left[S C N^{ominus}right] rightarrow ) ( left.left[mathrm{Cr} 9 mathrm{H}_{2} mathrm{O}right)_{5} mathrm{NCS}right]^{2+} mathrm{H}_{2} mathrm{O} ) The rate law is : ( r=kleft[mathrm{Cr}left(mathrm{H}_{2} mathrm{O}right)_{6}^{3+}left[mathrm{SCN}^{ominus}right]right. ) The value of k is ( 2.0 times 10^{-6} L m o l^{-1} s^{-1} ) at ( 14^{0} mathrm{C} ) and ( 2.2 times 10^{-5} L m o l^{-1} s^{-1}, ) at ( 30^{0} mathrm{C} ) What is the value of ( E_{a} ? ) A ( .26 k c a l m o l^{-1} ) B. ( 2.6 k )cal ( mathrm{mol}^{-1} ) c. ( 2600 k c a l ) mol( ^{-1} ) D. ( 260 k c a l ) mol( ^{-1} ) |
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950 | Two reactions ( R_{1} ) and ( R_{2} ) have identical pre-exponential factors. Actiation energy of ( R_{1} ) exceeds that of ( R_{2} ) by ( mathbf{1 0 k J}^{-1 . text { If }} boldsymbol{K}_{1} ) and ( boldsymbol{K}_{2} ) are rate constants for reactions ( boldsymbol{R}_{1} ) and ( boldsymbol{R}_{1} ) respectively at ( 300 mathrm{K}, ) then ( ln left(K_{1} / K_{2}right) ) is equal to 🙁 boldsymbol{R}=mathbf{8 . 3 1 4} boldsymbol{J}^{-1} boldsymbol{K}^{-1} ) ( A cdot 8 ) B. 12 ( c cdot 6 ) D. 4 |
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951 | The reaction, ( 2 N O+O_{2} rightarrow 2 N O_{2} ) proceeds in two steps. If one elementary reaction is ( N O+O_{2} rightarrow N O_{3}, ) write the second elementary reaction. Write the rate law of the reaction. |
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952 | For a certain reaction the rate law is rate ( =k[C]^{3 / 2} . ) If the rate of the reaction is ( 0.020 mathrm{mol} mathrm{L}^{-1} mathrm{s}^{-1} ) when ( [C]=1.0 mathrm{M} ) what is the rate when ( [C]=0.60 mathrm{M} ? ) begin{tabular}{l} A ( cdot 0.0093 mathrm{mol} mathrm{L}^{-1} mathrm{s}^{-1} ) \ hline end{tabular} B. ( 0.012 mathrm{mol} mathrm{L}^{-1} mathrm{s}^{-1} ) c. 0.033 mol ( L^{-1} s^{-1} ) D. ( 0.040 mathrm{mol} mathrm{L}^{-1} mathrm{s}^{-1} ) |
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953 | ( N O_{2} ) required for a reaction is produced by the decomposition of ( N_{2} O_{5} ) in ( C C l_{4} ) as per the equation ( mathbf{2} N_{2} O_{5}(g) rightarrow 4 N O_{2}(g)+O_{2}(g) ) The initial concentration of ( N_{2} O_{5} ) is 3.00 mol ( L^{-1} ) and it is 2.75 mol ( L^{-1} ) after 30 minute. The rate of formation of ( N O_{2} ) is : в. ( 4.167 times 10^{-3} ) mol ( L^{-1} ) min ( ^{-1} ) c. ( 8.333 times 10^{-3} ) mol ( L^{-1} min ^{-1} ) D. ( 1.667 times 10^{-2} ) mol ( L^{-1} min ^{-1} ) |
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954 | Write differential rate equation for the reaction, ( 2 A+B rightarrow ) product. | 12 |
955 | Rate law for the reaction, ( boldsymbol{A}+boldsymbol{B} longrightarrow ) product is rate ( =boldsymbol{k}[boldsymbol{A}]^{2}[boldsymbol{B}] . ) What is the rate constant; if rate of reaction at a given temperature is ( 0.22 M s^{-1}, ) when ( [boldsymbol{A}]=mathbf{1} boldsymbol{M} ) and ( [boldsymbol{B}]=mathbf{0 . 2 5} boldsymbol{M} ? ) ( mathbf{A} cdot 3.52 M^{-2} s^{-1} ) B . ( 0.88 M^{-2} s^{-1} ) c. ( 1.136 M^{-2} s^{-1} ) D. ( 0.05 M^{-2} s^{-1} ) |
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956 | The differential rate law for the reaction ( boldsymbol{H}_{2}+boldsymbol{I}_{2} rightarrow 2 boldsymbol{H} boldsymbol{I} ) is: A ( cdot-frac{dleft[H_{2}right]}{d t}=-frac{dleft[I_{2}right]}{d t}=-frac{d[H I]}{d t} ) B. ( frac{dleft[H_{2}right]}{d t}=frac{dleft[I_{2}right]}{d t}=frac{1}{2} frac{d[H I]}{d t} ) c. ( frac{1}{2} frac{dleft[H_{2}right]}{d t}=frac{1}{2} frac{dleft[I_{2}right]}{d t}=-frac{d[H I]}{d t} ) D. ( -2 frac{dleft[H_{2}right]}{d t}=-2 frac{dleft[I_{2}right]}{d t}=frac{d[H I]}{d t} ) |
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957 | Q Type your question 4 ( B ) ( c ) ( D ) |
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958 | A reaction has both ( Delta boldsymbol{H} ) and ( boldsymbol{Delta} boldsymbol{S} ) negative. The rate of reaction: A. Increases with increase of temperature B. Increases with decrease of temperature c. Remains unaffected by change of temperature D. Cannot be predicted for change in temperature |
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959 | A substance having rate constant ( k ) and initial concentration ( a ) reacts according to zero order kinetics. What will be the time for the reaction to go to completion? A ( cdot frac{a}{k} ) в. ( frac{k}{a} ) c. ( frac{a}{2 k} ) D. ( frac{2 k}{a} ) |
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960 | Hydrogentaion of vegetable ghee at ( 25^{circ} C ) reduces the pressure of ( H_{2} ) from 2 atm to 1.2 atm in 50 minute. The rate of reaction in terms of change of molarity per second is: A ( cdot 1.09 times 10^{-5} ) mollitre ( ^{-1} sec ^{-1} ) B. ( 2.90 times 10^{-5} ) mollitre ( ^{-1} ) sec ( ^{-1} ) c. ( 3.29 times 10^{-5} ) mollitre ( ^{-1} ) sec ( ^{-1} ) D. None of these |
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961 | A catalyst decrease ( E_{a} ) from ( 100 mathrm{kJ} ) ( m o l^{-1} ) to ( 80 mathrm{kJ} ) mol( ^{-1} . ) At what temperature the rate of reaction in the absence of the catalyst at ( 500 mathrm{K} ) will be equal to rate reaction in the presence of the catalyst: ( A cdot 400 K ) B. 200 K c. ( 625 mathrm{k} ) D. None of these |
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962 | ( 80 % ) of a first order reaction was completed in 70 min. How much it will take for ( 90 % ) completion of a reaction? A. 114 min B. 140 min c. ( 100 mathrm{min} ) D. 200 min |
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963 | For a first order reaction, the time required for ( 99.9 % ) of the reaction to take place in nearly: A. 10 times that required for half the reaction B. 100 times that required for two-third of the reaction c. 10 times that required for one-fourth of the reaction D. 20 times that required for half of the reaction. |
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