Chemical Kinetics Questions

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.

Chemical Kinetics Questions

List of chemical kinetics Questions

Question NoQuestionsClass
1The 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
12
2According 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.
12
3Rate 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
12
4Question 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.
12
5A 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?
12
6For 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
12
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
12
8For 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
12
9For 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} )
12
10If 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
12
11For 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
12
12Q Type your question
( A )
B.
( c )
( D )
12
13For 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
12
14What 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} )
12
15At ( 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 )
12
16At 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} )
12
17LLOS
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-
12
18Which 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] )
12
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
12
20The 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} )
12
21To 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 )
12
22In 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} )
12
23Two 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
12
24The 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
12
25At what time, there will be 6400 bacteria in the flask?
A. ( 150 mathrm{min} )
B. 90 min
c. ( 160 min )
D. ( 120 mathrm{min} )
12
26A 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
12
27The 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
12
28Reaction ( 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 ) )
12
29Write any two characteristics of first
order reaction.
12
30Sucrose 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?
12
31For 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} )
12
32For 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 )
12
33Let 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) )
12
34The 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 )
12
35Question 21. All energetically effective collisions do not results in a
chemical change. Explain with the help of an example.
12
36What 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
12
37A 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.
12
38Nitrogen 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} )
12
39Question 22. What happens to most probable kinetic energy and the
energy of activation with increase in temperature?
12
40For 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
12
41First 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
12
42A 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
12
43From 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 )
12
44The 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
12
45The 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
12
46Energy produced in a chemical reaction is a specific type of :
A. kinetic energy
B. elastic energy
c. potential energy
D. entropy
E. thermal energy
12
47Which 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 )
12
48Assertion
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
12
49What is activation energy?12
50The 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
51Statement 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.
12
52The 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} )
12
53The rate of reaction does not depend
upon
A. Temperature
B. Concentration
c. catalyst
D. None of these
12
54Assume 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?
12
55Assertion
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
12
56The 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} )
12
57In 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.
12
58A 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} )
12
59A 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
12
60The 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} )
12
61The 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
12
62Assertion: 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
12
63For 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} )
12
64What 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
12
65While 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.
12
660.9 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
12
67The 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} )
12
68Observation 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.
12
69Consider 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} )
12
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%
12
71A 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
12
72The 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?
12
73In 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.
12
74If ( 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 )
12
75For 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
12
76Higher 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
12
77At 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
12
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
12
79The 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 )
12
80The 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) )
12
81A 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} )
12
82For 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] )
12
83In 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
12
84Speed of a chemical reaction increases with ( _{-}–_{-}-_{-}-_{-}-_{-} ) in temperature
A. decreases
B. increases
c. no change
D. can’t say
12
85Arhenius equation is not applicable for:
A . first order reactions
B. second order reactions
c. zero order reaction
D. radioactive decay
12
86.48 Thermodynamic feasibility of the reaction alone cannot decide the rate
of the reaction. Explain with the help of one example.
12
87Write definition of molecularity of
reaction.
12
88Which 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} )
12
89Q. 52 Why can we not determine the order of a reaction by taking
consideration the balanced chemical equation?
Collowing
12
90Which 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
12
91Order 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
12
92A reaction is ( 50 % ) complete in 2 hours and ( 75 % ) complete in 4 hours. The order
of reaction is:
A.
B.
( c cdot 2 )
D.
12
93Question 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?
12
94If 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
12
95The rate of the chemical reaction
doubles for and an increase of ( 10 K ) in
absolute temperature from ( 298 K )
Calculate ( boldsymbol{E}_{boldsymbol{a}} )
12
96Question 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!
12
97What is slow and fast reaction? Give
example.
12
98The 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-
12
99For 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
12
100A 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.
12
101For 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} )
12
102A first order reaction is ( 50 % ) complete in 25 minutes. Calculate the time for ( 80 % )
completion of the reaction.
12
103For 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) )
12
104The 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
12
105In 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
12
106For 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] )
12
107Acid 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} )
12
108Which 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)} )
12
109Question 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.
12
110The 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} )
12
111The 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} )
12
112In 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} )
12
113The 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
12
114A 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?
12
115Question 7. For a reaction, A+B – products, the rate law is
rate = k [A][B]32. Can the reaction be an elementary reaction? Explain.
12
116The 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
12
117The 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
12
118Acid 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) )
12
119For 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} )
12
120Derive the relationship showing
variation in rate constant with
temperature
12
121The 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) )
12
122In 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} )
12
123Derive the integrated rate equation for expressing the rate constant of a first order:
( boldsymbol{R} rightarrow boldsymbol{P} )
12
124The 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
12
125Assertion
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
12
126For 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 )
12
127For 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
12
128The 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
12
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
12
130If 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
12
131Which 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
12
132The unit of rate of reaction varies with
order of reaction.
A . True
B. False
12
133An 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
12
134Among 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
12
135If ( 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 )
12
136Which 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) )
12
137For 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 )
12
138For 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:
12
139The 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
12
140Consider 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} )
12
141A 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?
12
142Assertion
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
12
143constant 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.
12
144The 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
12
145A 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} )
12
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
12
147Which 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
12
148Specific reaction rate is rate of reaction at unit concentration of reactants.
A. True
B. False
12
149The 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] )
12
150Consider 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} )
12
151For 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
12
152Question 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)
12
153For 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
12
154For 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
12
155For 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} )
12
156According 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
12
157If ( 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
12
158of a reaction cannot be
determined experimentally
A. Order
B. Rate
c. Rate constant
D. Molecularity
12
159A 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:
A ( .5 .49 times 10^{-3} ) mol litre ( ^{-1} ) sec ( ^{-1} )
B. ( 5.55 times 10^{-3} ) mol litre ( ^{-1} ) sec ( ^{-1} )
c. ( 7.49 times 10^{-3} ) mol litre ( ^{-1} ) sec ( ^{-1} )
D. None of these

12
160For 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 )
12
161For 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
12
162Which 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 )
12
163Match the column12
164For 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
12
165The 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) )
12
166Units 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} )
12
167is 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} )
12
168In 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} )
12
169For 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}
12
170During 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.
12
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
12
172A 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
12
173Reaction, ( 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} )
12
174The rate constant of a first order
reaction is ( 1.54 times 10^{-3} ) sec ( ^{-1} ). Calculate
its half life period.
12
175For 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}) )
12
176The reaction of nitrogen and oxygen to form nitric oxide is favored by high temperature.
A. True
B. False
12
177At ( 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} )
12
178The 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} )
12
179Explain the concept of reaction with no
order.
12
180When 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
12
181The molecularity of a reaction will be:
A . fractional
B. zero
c. positive whole number
D. negative
12
182The 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
12
183The 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} )
12
184In 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)} )
12
185For 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}) )
12
186In 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.
12
187The 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.
12
188For 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
12
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) )
12
190The 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 )
12
191A 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?
12
192The 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 )
12
193Reaction rate increases
with
A. concentration
B. pressure
c. both a and ( b )
D. none of above
12
194Write four differences between rate of
reaction and constant.
12
195The 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 )
12
196The 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
12
197suppose 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
12
198Slowest 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 )
12
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
12
200During 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} )
12
201C if the
Question 2. Write the rate equation for the reaction, 2A + B
order of the reaction is zero.
12
202Question 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.
12
203A 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
12
204A 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] )
12
205With 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
12
206For 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} )
12
207Which 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} )
12
208The 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
12
209For 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
12
210Consider 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
12
211How an increase in concentration is
related to number of collisions?
A. Directly
B. Inversely
c. Has no effect
D. None
12
212Decomposition 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
12
213For 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
12
214The 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} )
12
215Q.51 Why molecularity is applicable only for elementary reactions and order is
applicable for elementary as well as complex reactions?
Aanmelawati
12
216The 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
12
217When 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 )
12
2180.58 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.
12
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
220The 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
12
221Trimolecular 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
12
222Consider 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
12
223. 46 What is the probability of reaction with molecularity higher than three
very rare?
all
thoro must
12
224In 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
12
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?
A. ( C H_{3} C l ) is an intermediate because it is made in step and used in step 4
B. The order of the reaction with respect to ( C H_{4} ) is one since step 2 is the slowest step, making the rate law for step 2: rate ( =kleft[C H_{4}right][C l] )
c. The first step is the only equilibrium step in the reaction
D. The overall rate law for the reaction is: rate( = ) ( kleft[C H_{4}right]left[C l_{2}right] )

12
226For a reaction, calculate value of ratio, ( frac{[x]_{t}}{[y]+[z]} ) at any given instant ( t )12
227Consider 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
12
228The 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
12
229The 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
12
230The 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
12
231Which 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}} )
12
232In 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
12
233Question 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
12
234Question 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.
.
12
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.
12
236Units of rate constant of a first order
reaction is :
A . mole.lit”
B. lit.mole
c. mole.sec ( ^{-1} )
D. ( sec ^{-1} )
12
237The 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.
12
238In 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
12
2392
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
12
240The 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
12
241If 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} )
12
242The 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.
12
243A 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
12
244A 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}}
]
12
245How 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
12
246The 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 )
12
247What names apply to chemical species
corresponding to locations 1 and 2 on
this reaction coordinate diagram?
Location 1

Location 2
A. Activated complex Activated complex
B. Reaction intermediate Activated complex
c. Activated complex Intermediate
D. Reaction intermediate Intermediate

12
248In 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.

12
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
12
250Which of letter shows the enthalpy
change ( (triangle boldsymbol{H}) ) of the reaction?
( A )
B.
( c . c )
( D )
E.
12
251Which 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} )
12
252What happens to the half life period for a first order reaction, if the intial concentration of the reactants is
increased?
12
253For 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
12
254Which 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
12
255dentify the type of reaction indicated by
( D ) in the diagram.
A. Uncatalyzed exothermic
B. Catalyzed exothermic
c. Catalyzed endothermic
E. Reversible
12
256Collision 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 )
12
257For 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 )
12
258NaOH can’t be stored in
( mathbf{A} cdot ) Al vessel
B. Zn vessel
c. Both a and
D. None of these
12
259In 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
12
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} )
12
261In ( _{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
12
262The 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} )
12
263What is half-life of a reaction? Derive
formula for finding out half-life from
first order rate reaction.
12
264A 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.
12
265idy 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
12
266The 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 )
12
267Question 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%
12
268The 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
12
269In 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} )
12
270The 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
12
271For 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} )
12
272The 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.
12
273In 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} )
12
274Total 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} )
12
275Rate 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} )
12
276unchanged 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
12
277For 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 )
12
278Arsine 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) )
Calculate the specific rate and half-life
peroid of reaction assuming the reaction to be of first-order.

12
279Question 13. Oxygen is available in plenty in air yet fuels do not burn
by them selves at room temperature. Explain.
12
280Statement – 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
12
281The 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} )
12
282In 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 )
12
283The order of reaction for which half-life
period is independent of initia
concentration is:
A. zero
B. first
c. second
D. third
12
284From 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] )
12
285The 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 )
12
286The 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
12
287The 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
12
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
12
289The 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} )
12
290Why 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
12
291The 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.
12
292А-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
12
293The 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} )
12
294Define collision frequency. Give an example for Pseudo-first order reaction.12
295In 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} )
12
296For 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
12
297For 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 )
12
298In 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.
12
299Consider 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
12
300State whether the statement is True or
False:

Two molecules can react only if they have a correct relative orientation.

12
301increases 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 )
12
302The 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} )
12
303A 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 ) ).
12
304The rate of reaction w.r.t reactants is
indicated by a negative sign
A. True
B. False
12
305Rate 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
12
306The 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
12
307Assertion
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
12
308If 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.
12
309If 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} )
12
310A 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
12
311What is order of reaction? Write unit of
rate constant ( K ) for the zero order, first
order and second order reaction.
12
312Statement 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.
12
313For 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
12
314The 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
12
315The 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} )
12
316Triple 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} )
12
317Question 1. State a condition under which a bimolecular reaction is
kinetically first order reaction.
12
318Which 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
12
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} )
12
320What 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} )
12
321Following 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
12
322In 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
12
323A 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?
12
324For 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)
12
325Consider 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
12
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
12
327A 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:
12
328Consider 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
12
329For 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} )
12
330On 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
12
331In 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} )
12
332An 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) )
12
333Two 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} )
12
334the 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
12
335The rate of reaction is uniform
throughout the reaction.
A. True
B. False
12
336In 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”
12
3370.8 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
12
338Q. 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
12
339Which 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
12
340For 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
12
341Question 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.
12
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
12
343When 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
12
344Answer the following questions:
1. Define instantaneous rate of reaction.
2. Explain pseudo first-order reaction with suitable example.
12
345Write the rate law for -Reaction is zero
order in ( A ) and second order in ( B ).
12
346In 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} )
12
347Explain, with the help of potential energy diagram, effect of temperature
on the rate of reaction.
12
348The time required for a first-order reaction for ( 99 % ) completion is ( x ) times
for the time required for ( 90 % )
completion. ( boldsymbol{x} ) is:
12
349For 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?
12
350The 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} ) :

12
351A 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
12
352Which 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} )
12
353Question 14. Why is the probability of reaction with moleculartity
higher than three very rare?
12
354If
( A rightarrow ) products is a first order reaction then, write the integrated law equation.
12
355Define order of reaction.12
356Activation 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
12
357The 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} )
12
358The 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
12
359In 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.
12
360Which 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} )
12
361Write the difference between order and
molecularity of a reaction.
12
362Collision diameter is least in case of:
A ( . H_{2} )
в. ( H e )
( c cdot C O_{2} )
D. ( N_{2} )
12
363A 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
12
364Consider 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} )
12
365What 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
12
366Q. 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
12
367The 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.
12
368The 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
12
369The 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 )
12
370In 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
12
3710.47 Why does the rate of any reaction generally decreases during the course
of the reaction?
to reaction
12
372The 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:
12
373For 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 )
12
374Write notes on consecutive reactions
with an example.
12
375What 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 )
12
376The 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.
12
377If 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
12
378Question 19. Why molecularity is applicable only for elementary
reactions and order is applicable for elementary as well as complex
reactions?
12
379Question 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
12
380Question 15. Why does the rate of any reaction generally decreases
during the course of the reaction?
12
381Which 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
12
382Q. 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
12
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
12
384The 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
12
385Write 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}) )
12
386Reaction, ( 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} )
12
387For 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) )
12
388Which 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
12
389Consider 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.
12
390What 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
12
391For 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.
12
392In 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
12
393Statement 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
12
394Question 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.
12
395The 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
12
396What are the units of rate constant of a
pseudo unimolecular reaction?
12
397A 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
12
398Catalytic 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
12
399The rate of simple reaction ( 2 N O+ )
( O_{2} longrightarrow 2 N O_{2}, ) when the volume of the
reaction vessel is doubled.
12
400The 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
12
401If 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} )
12
40227 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
12
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
12
404Which 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
12
405For ( 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} )
12
406The 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} )
12
407An 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) )
12
408Units of average rate of reaction is:
( A cdot sec ^{-1} )
B. mole sec ( ^{-1} )
c. mole ( mathrm{dm}^{-3} mathrm{sec}^{-1} )
D. unitless
12
409In 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%?
12
410Figure 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} )
12
411In 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.
12
412Assertion
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
12
413Assertion
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
12
414At ( 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] )
12
41511. 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 )
12
416The 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}} )
12
417Which 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
12
418In 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.
12
419The volume of dry ( N_{2} O ) produced at this point measured at STP is
L)
12
420Chemical 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
12
421What are pseudounimolecular reactions? Explain the help of suitable
example.
12
422Question 3. How can you determine the rate law for the following
reaction?
2NO(g) + O2(g) → 2NO2()
function of
12
423If 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 )
12
424In 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 )
12
425For 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} )
12
426Which 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
12
427Consider 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
12
428Given 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} )
12
429The rate of reaction that does not
involve gases, is not dependent on:
A. pressure
B. temperature
c. concentration
D. catalyst
12
430For 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
12
431The 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
12
432The 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
12
433The 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
12
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
12
435A 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
12
436For 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]
12
437For 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
12
438Derive an expression for integrated rate law for a zero order reaction.12
439Mathematical 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} )
12
440A 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} )
12
441Which 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
12
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
12
443In 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
12
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} )
12
445Thermal 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?
12
446Write the two steps involved in the
mechanism of the enzyme-catalyzed
reaction.
12
447Unit of the rate of reaction is:
A. concentration
B. concentration ( times ) time
c. concentration
D. concentration ( ^{2} )
12
448For 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
12
449In a first order reaction, ( 1010 % ) is
complete Calculate:The half life of the
reaction:
12
450Q. 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
12
451For 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] )
12
452In a first order reaction with time the
concentration of the reactant
decreases:
A. Linearly
B. Exponentially
c. No change
D. None of these
12
453The 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
12
454The 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
12
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?
12
456If 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 )
12
457For 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] )
12
458The speed of a reaction is determined
by:
A. rate of reaction
B. temperature of reaction
c. nature of reactant
D. flow of reactants
12
459The 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
12
460For 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
12
461Q. 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
12
462Question 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
12
463Which 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} )
12
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
12
465The 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
12
466Assertion
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
12
467For 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
468The 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} )
12
469In 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} )
12
470The 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
12
471Decomposition 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
12
472A 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
473The 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
12
474The 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 % )
12
475The 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
12
476For 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
12
477What 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
12
478A 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
12
479Ans.(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
12
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.
12
481A first order reaction takes 69.3
minutes for ( 50 % ) completion. How much time will be needed for ( 80 % )
completion?
12
482The 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
12
483For 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]} )
12
484Reactions 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} )
12
486For 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}^{-} )
12
487Change 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
12
4882.58 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.
12
489Identify 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
12
490A 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.
12
491Effective 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
12
492If 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.
12
493If 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) )
12
494The 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%
12
495Fastest 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} )
12
496In 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
12
497Give a detailed account of the collision
theory of reaction mils of Bimolecular gaseous reactions.
12
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
12
499Thermal 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.
12
500In 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
12
501In 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} )
12
502The 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
12
503The 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
12
504The 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} )
12
5050.60 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.
12
506A 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
12
507What 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
508In 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
12
5090.36 For which type of reactions, order and molecularity have the same value?12
510The 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
511The 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
12
512The 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} )
12
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: )
12
514At ( 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
515Q 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
12
516The 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} )
12
517For 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
518Explain 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.
12
519How can the rate of the chemical
reaction, namely, decomposition of hydrogen peroxide be increased?
12
520The 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
521The 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
522For 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
523Question 18. Why can’t molecularity of any reaction be equal to zero?12
524According to collision theory, write
name of two factors which increases
the rate of reaction as temperature increase.
12
52518. 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
526Express 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
528The 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
529Which 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
530The 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
531In 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
532The 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
533A 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
534Question 4. For which type of reactions, order and molecularity have
the same value?
12
535A 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
536Activation 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
537The 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
538O
.35 How can you determine the rate law of the following reaction?
2NO(g) + O2(g) → 2NO, (g)
12
539Use 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
540Question 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
541The 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
542For 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
543The 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
544Assertion
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
545One 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
546For 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
547For 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
548Which 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
549Which 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
550A 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
551For 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
5520.4 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
553The half life of a first order reaction is
1.7 hours. How long will it take for ( 20 % ) of the reactant to disappear?
12
554If the unit of rate constant of a reaction
is ( m o l^{-1} L S^{-1} ) then mention its order.
12
555In 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
556Reaction ( 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
557If ( 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
558The 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
559For 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
560Rate 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
561The 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
562Question 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
563Consider 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
564Determine the average life ( U^{238} ) having
( t_{1 / 2}=140 ) days.
12
565Why 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
567Consider 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
568Which 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
569The 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
570The 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
571Q. 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
572For 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
573A 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
574For 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
575For 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
576Assertion
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
12
577An 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
578Question 12. Why does the rate of a reaction increase with rise in
temperature?
12
579Graph 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
12
580Which 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
581The 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
582All first order reactions are
unimolecular.
A. True
B. False
12
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
12
584Question 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].
12
585Instantaneous rate and average rate of a reaction are same when ( Delta boldsymbol{t} rightarrow mathbf{0} )
If true enter 1 , else enter 0
12
586Inversion 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
12
588Which 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
589The 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
12
590Chemical 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
12
591For 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?
12
592Q.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
12
593The 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
12
594The 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
595If its given :
Half-life ( alpha frac{1}{a}, ) what will be the order? Will it
be ( 2 ? )
12
596At ( 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
597The 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 )
12
598The 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
599Question 24. With the help of an example explain what is meant by
pseudo first order reaction.
12
600Half 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
601The 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} )
12
602The 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} )
12
60313. 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
12
604The 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
12
605A 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
606reactor 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
607Cyclopropane 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 )
12
608In 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.
12
609A 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
12
610Consider 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
12
611For gaseous reaction what is the unit of
rate of reaction?
12
612For 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} )
12
613In 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
614Q. 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
615Fill 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
616Q.50 Why can’t molecularity of any reaction be equal to zero?
antaroton
12
617If 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
618An 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
12
619The 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
620If ( Delta t rightarrow 0 ) the average rate changes to
A . infinitesimal rate
B. small rate
c. instantaneous rate
D. fast rate
12
621In 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
doubled and the rate of the reaction
increases by a factor of eight, what can be concluded from the reaction?
A. The order of reactant ( B ) in the overall rate law is 3
B. The order of reactant ( A ) in the overall rate law is 1
c. The order of reactant ( B ) in the overall rate law is 2
D. The order of reactant ( B ) in the overall rate law is 1
E. The order of reactant ( A ) in the overall rate law is 3

12
622In 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
12
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. )
12
624What 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
625Find 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
12
626Q.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
627In 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
628Calculate 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) )
12
629For 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} )
12
630Units of rate of reaction are mole ( l^{-1} s^{-1} )
A . True
B. False
12
631What 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} )
12
632The 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
633Molecules must collide before they
react.
If true enter ( 1, ) if false enter 0
12
634Question 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
12
635anism
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
12
636Two 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.
12
637If the rate of reaction is equal to the rate constant, the order of the reaction is:
A. 0
B.
( c cdot 2 )
( D )
12
638The rate of chemical reaction is directly proportional to the equilibrium constant.

In which of the following process reaction will be completed first?
A. ( K=10 )
B . ( K=1 )
( mathbf{c} cdot K=10^{3} )
D. ( K=10^{-2} )

12
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
12
640When 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
641The 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
642At ( 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} )
12
643The 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} )
12
644For 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
12
6450.54 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
12
646The activation energy for a chemical reaction depends upon:
A. reaction
B. nature of reacting species
c. frequency factor
D. concentration of reacting species
12
647For 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
12
648Which 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} )
12
649What 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
12
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?
12
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
12
652What is activation energy?12
653In 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
12
654The 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
12
655Q. 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
12
656The 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
12
657The 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
12
658The 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.
12
659The 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)} )
12
660The 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
12
661The 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)
12
662The 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] )
12
663The 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
12
664What 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
12
665For 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
12
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 ? )
12
667A first order reaction takes 40 min for
( 30 % ) decomposition. Calculate ( t_{1 / 2} )
12
668In 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
669A 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
670For 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} )
12
671Question 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
672For 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
673Assertion
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
12
674The 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
675The 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
676What 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
677In 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
12
678The 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
679Discuss the characteristics of order of a
reaction.
12
680A 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
681When 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
682If 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
12
683In 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) )
12
684A 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
685For 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} )
12
686For 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} )
12
687For 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
688At 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 )
12
689As 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
690The 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
6910.28 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
692For 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
693The 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
694C if the order of
Q. 34 Write the rate equation for the reaction 2A + B
the reaction is zero.
12
695For 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?
12
696A 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
12
697For 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
698For 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} )
12
699Pseudo 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.
12
700Why 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
12
701dentify the type of reaction indicated by
line ( A ) in the diagram.
A. Uncatalyzed exothermic
B. Catalyzed exothermic
c. Catalyzed endothermic
E. Reversible
12
702The 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
704The 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
705Calculate the mass of ( C^{14} ) (half life ( = )
( 5720 text { years }) ) atoms which give ( 3.7 times 10^{7} )
disintegrations per second.
12
706For an elementary process ( 2 X+Y rightarrow )
( Z+W ). the molecularity is-
( A cdot 2 )
B.
( c .3 )
D. unpredictable
12
707Question 17. Why in redox titration of KMnO4 vs oxalic acid, we heat
oxalic acid solution before starting the titration?
12
708For 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
709For 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
710A 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
711If 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
712At ( 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
713What is the mathematical equation for the rate constant for the decomposition
of nitrous oxide in presence of platinum catalyst?
12
714For 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
715For 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
716The 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
717A 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
718Which 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
719The 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
720In 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
721In a slow reaction, rate of reaction
generally with time.
A. decreases
B. increases
c. sometimes increases and sometimes decrease
D. remain constant
12
722The 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
723What 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
724The 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
725The 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
727For 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
728Question 9. For a zero order reaction will the molecularity be equal to
zero? Explain.
12
729Statement: The rate of instantaneous
reactions can be determined
experimentally.
State whether the given statement is
true or false.
A. True
B. False
12
730For 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
731The 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
732The 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
733What 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
734The 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
735Tollen’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
736In 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
737Which 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
738Write two factors affecting on the rate of chemical reaction.12
739The 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
740In 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
741The 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
742Question 23. Describe how does the enthalpy of reaction remain
unchanged when a catalyst is used in the reaction?
12
743Which 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
744In 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
745For 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
746If 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
747A 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
748On 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
749For 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
750A 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
751Write the units of rate constants for
zero order and first order reactions.
12
752The 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
754Rusting of iron is an example of reaction.
A . fast
B. slow
c. endothermic
D. can’t say
12
755A first order reaction is found to have a
rate constant, ( k=5.5 ; ) find the half life of
the reaction.
12
756If ( 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
757From 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
758Which 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
759Match the column12
760The 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
761Fora 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
763In 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
764Which 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
765Question 20. Why can we not determine the order of a reaction by
taking into consideration the balanced chemical equation?
12
766In 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
767Question 16. Thermodynamic feasibility of the reaction alone cannot
decide the rate of the reaction. Explain with the help of one example.
12
768What 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
769Rate 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
770When a catalyst increases the rate of a chemical reaction, the rate constant:
A. increases
B. decreases
c. remains constant
D. becomes infinite
12
771For 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
772In 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
773A 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
774The 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
775For 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
776The 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
777For 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
778Question 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
779Assertion: 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
780D. 45 Oxygen is available in plenty in air yet fuels do not burn by themselves
at room temperature. Explain.
12
781The 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
782Catalysts 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
783Assertion: If the activation energy of reaction is low, it proceeds at a faster rate.

Reason: Lowering activation energy increases the kinetic energy of molecules.
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
784The 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
12
785At 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
786Molecularity 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
787For a first order reaction, show that time
required for ( 99 % ) completion is twice the
time required for the completion of ( 90 % )
of reaction.
12
788What 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} )
12
78910.38 Derive an expression to calculate time required for completion of zero
order reaction.
P
a r panatia
Di
12
790The 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} )
12
791Question 6. Derive an expression to calculate time required for
completion of zero order reaction.
12
792Explain with an example how the concentration of the reactants affects
the rate of a chemical reaction.
12
793A transition state represents the state
of highest energy in passing from reactant to product. If true enter 1 , if false enter 0 .
12
794In 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
795From 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
796Which 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
797The higher the
temperature
A. lower the energy
B. higher the energy
C. moderate energy
D. none of above
12
798The 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
799Observe 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
800From 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
801In 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
802For the reaction ( 2 N H_{3(g)} frac{1130 K}{M o} )
( N_{2(g)}+3 H_{2(g)}, ) the order is:
12
803Q. 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
804For 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
805Express 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
806Match 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
807The 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
808For 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
809The rate constant of a reaction does not
depend upon:
A. temperature
B. activation energy
c. catalyst
D. concentration of reactants and products
12
810A 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
811Catalytic 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
812In 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
813The 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
814The 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
816The 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
817What is half life period of a reaction?
Calculate the half life period of a first
order reaction?
12
818Q. 62 All energetically effective collisions do not result in a chemical change.
Explain with the help of an example.
bet mollisions in which
12
819Two 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
820What 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
821What is average rate of a chemical
reaction?
12
822Which 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
823Reaction ( =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
824For 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
825A 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
826Which letter shows the potential energy
of the products?
( A cdot A )
( B )
( c )
( D )
( E )
12
827Activation 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
8281 ( 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
829A 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
830In 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
831Which 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
832Which 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
834Two 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
835For 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
836On 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
837For 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
838Write the order of reaction in which unit
of rate and rate constant becomes
equal?
12
839Which 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
840The 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
841O. 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
842The 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
843Question 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
844For 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
845Consider 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} )
12
846For 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
847Instantaneous 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
848For 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
849For 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} )
12
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
851What 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
852Rate 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
853Decomposition of ozone shows negative
order with respect to oxygen.
A. True
B. False
12
854Units 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
855What 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
856Which 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
857The 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
12
858For 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} )
12
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} )
12
860After 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
12
861Which 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
12
862For 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
12
863An 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
12
864Rate constant (K) of a first order
reaction is ( 5.5 times 10^{-14} s e c^{-1} . ) Find the
half life of reaction.
12
865For 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} )
12
866Q 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 )
12
867For 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} )
12
868A 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?
12
869Question 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.
12
870The 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) )
12
871Which 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 )
12
87230
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 !
12
873In 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} )
12
874The 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
12
875Consider 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} )
12
876Write four differences between
molecularity and order of reaction.
12
877What 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?
12
878Calculate 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}
]
12
879Question 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
12
880Explain:
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.
12
881The 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.
12
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
883For 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 )
12
884Q. 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
12
885The 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
12
886In 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
887Define pseudio first order reaction Show that half life of zero order reaction
is directly proportional to concentration of reactant.
12
888The 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
889The 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} )
12
890For 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
891At ( 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
12
892Consider 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
893For 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
894Which 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
895toppr ( 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
896The 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
897What 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
898In 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} )
12
899In 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
900Ethylene 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
901The 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
902If the half life period for a first order
reaction is 69.3 seconds, what is the
value of its rate constant?
12
903The 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
906A 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
907Rate 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
908In 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
909The 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
910The 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
911Select 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
912Give the unit of rate of reaction.
A. Molar
B. Second
c. Second/molar
D. Molar/second
12
913For 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
914The 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
915What is pseudo first order reaction?
Give one example of it.
12
916What 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
917Rate 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
918The 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
919For 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
920Consider 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
| ( E_{a} ) is always greater than ( triangle H )
For an exothermic reaction, adding a catalyst
III ( quad ) will decrease the magnitude of ( triangle H )
A. Statement I only is true.
B. Statement II only is true.
C. Both statements I and II are true.
D. Both statements I and III are true.

12
921Trans-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
923Q. 41 For a zero order reaction will the molecularity be equal
will the molecularity be equal to zero? Explain.
the number of
12
924Which 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
925If 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
926Show 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
927Which 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
928The 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
929Rate 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
930Calculate 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
931The 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
932Chemical 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
933Assertion
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
934The 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} )
12
935Two 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 )
12
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} )
12
937What is psuedo first order reaction? Give an example.12
938The 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?
12
939In 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)
12
940At ( 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} )
12
941For 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
12
942Here 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?
A. The slope represents the change in concentration over time
B. The slope represents the inverse of change in concentration over time
c. The slope represents the negative value of the rate constant
D. The slope represents the negative rate of product concentration over time

12
943Find 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} )
12
944For 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
12
945Which 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
12
946A 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} )
12
947Which 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
12
948Derive the relation between half life and
rate constant for a first order reaction.
12
949For 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} )
12
950Two 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
12
951The 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.
12
952For 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} )
12
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} )
12
954Write differential rate equation for the reaction, ( 2 A+B rightarrow ) product.12
955Rate 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} )
12
956The 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} )
12
957Q Type your question
4
( B )
( c )
( D )
12
958A 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
12
959A 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} )
12
960Hydrogentaion 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
12
961A 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
12
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
12
963For 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.
12

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