We provide general principles and processes of isolation of elements practice exercises, instructions, and a learning material that allows learners to study outside of the classroom. We focus on general principles and processes of isolation of elements skills mastery so, below you will get all questions that are also asking in the competition exam beside that classroom.
List of general principles and processes of isolation of elements Questions
| Question No | Questions | Class |
|---|---|---|
| 1 | The common impurity present in bauxite is: ( mathbf{A} cdot F e_{2} O_{3} ) в. ( A l_{2} O_{3} . H_{2} O ) c. ( A l C l_{3} . A I_{2} O_{3} ) D. ( M g C l_{2} . C a C l_{2} ) |
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| 2 | Which one of these is the ore of manganese? A. Pyrolusite B. Cinnabar c. Galena D. Malachite |
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| 3 | Differentiate between minerals and ores. |
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| 4 | What is metallurgy? | 12 |
| 5 | In the extraction of copper, the copper matte is a mixture of: A. copper (II) sulphide and iron (II) sulphide B. copper (II) sulphide and iron (III) sulphide C . copper (I) sulphide and iron (II) sulphide D. copper (I) sulphide and iron (III) sulphide |
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| 6 | (i) Metals can be recovered from their ores by chemical methods. (ii) High purity metals can be obtained by zone refining method. Which one is true /false. A . (i) is true and (ii) is false B. (ii) is true and (i) is false c. (i) and (ii) are true D. (i) and (ii) are false |
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| 7 | Which of the following statements is correct according to the basic concept of thermodynamics which govern the feasibility of a metallurgical process? A. When the value of ( triangle G ) is positive for the equation ( Delta G= ) ( triangle mathrm{H}-mathrm{T} Delta mathrm{S} ), the reaction will proceed B. If reactants and products of two reactions are put together and net ( triangle G ) is -ve, the overall reaction will occur c. on increasing the temperature, the value of ( triangle G ) becomes +ve D. Feasibility of thermal oxidation of an ore can be established by Ellingham diagram in which a straight line shows the reduction reaction will proceed. |
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| 8 | Assertion Refining of zinc is done by distillation under reduced pressure. Reason Zinc is a transition metal. |
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| 9 | The ore that contains both iron and copper is: A. malachite B. dolomite c. azurite D. copper pyrites |
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| 10 | Anthracite is an ore of Fe? A. True B. False |
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| 11 | ( 100 % ) copper is obtained from crude copper by : A. zone refining method B. electrorefining c. liquation D. poling |
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| 12 | Which of the following is used as a method of purification for silicon? A. Electrolytic refining B. Liquation c. zone refining D. Distillation |
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| 13 | Mac Arthur process is used for the extraction of ( A cdot A l ) B. Agg ( c cdot c u ) D. zn |
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| 14 | In froth floatation process, gangue articles are wetted by pine oil A. True B. False |
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| 15 | Explain the role of each of the following. (i) NaCN in the extraction of silver (ii) ( S i O_{2} ) in the extraction of copper |
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| 16 | The main reaction(s) which occur(s) in blast furnace during extraction of iron from haematite is(are): This question has multiple correct options A. ( 2 F e_{2} O_{3}+3 C rightarrow 4 F e+3 C O_{2} ) в. ( F e O+S i O_{2} rightarrow F e S i O_{3} ) c. ( F e_{2} O_{3}+3 C O rightarrow 2 F e+3 C O_{2} ) D. ( C a O+S i O_{2} rightarrow C a S i O_{3} ) |
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| 17 | Borax is used as cleansing agent because on dissolving in water it gives A. alkaline solution B. acidic solution c. bleaching solution D. colloidal solution |
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| 18 | Electrometallurgy is the field concerned with the processes of metal electrodeposition. A. True B. False |
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| 19 | The transition metal present in the alloy gun metal is ( mathrm{Cu} ) | 12 |
| 20 | Question 13. How are the metals used as semiconductors refined What is the principle of the method used? |
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| 21 | Draw an Ellingham diagram for metal oxides and explain what information can be obtaines from it.ln addition explain why why most of the lines slope upwards from left 10 right,why the lines change in slope, and what happens when a line crosses the ( Delta G=0 ) axis |
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| 22 | Consider the following metallurgical processes: 1) Heating impure metal with ( mathrm{CO} ) and distilling the resulting volatile carbonyl (b.pt. ( left.43^{circ} mathrm{C}right) ) and finally decomposing at ( 150^{circ} mathrm{C} ) to ( 230^{circ} mathrm{C} ) to get the pure metal. 2) Heating the sulphide ore in the air until a part is converted to oxide and then further heating in the absence of air to let the oxide react with unchanged sulphide. 3) Electrolyzing the molten electrolyte containing ( C a C l_{2} ) to obtain the metal. The processes used for obtaining sodium, nickel and copper are, respectively: A. 1,2 and 3 B. 2, 3 and 1 c. 3,1 and 2 D. 2,1 and 3 |
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| 23 | 43. Cryolite is (1) Al(OH), (3) Naz AlF6 (2) KAI SI,O, (4) A1,03 |
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| 24 | In the metallurgy of copper, the impure metal got after Bessemerization is called: A. Blister copper B. Wrought copper c. Brass copper D. Pig copper |
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| 25 | In electrolysis of ( A l_{2} O_{3} ) by Hall- Heroult process, A. cryolite ( N a_{3}left[A l F_{6}right] ) lowers the ( m . p . ) of ( A l_{2} O_{3} ) and increases its electrical conductivity B. Al is obtained at cathode and probably ( C O_{2} ) at anode c. Both (a) and (b) are correct D. None of the above |
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| 26 | Name the method used for refining of nickel. |
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| 27 | Assertion Silica is added as a flux in a reverberatory furnace, in the extraction of copper for copper pyrites. Reason Silica acts as basic flux. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is correct but Reason is incorrect D. Assertion is incorrect but Reason is correct |
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| 28 | Explain zone – refining (figure not necessary. | 12 |
| 29 | Question 6. The purest form of iron is prepared by one from cast iron in a reverberatory furnace. Which iron ore the furnace? Explain by giving reaction. parties ose to ime |
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| 30 | The white precipitate (P) is: ( mathbf{A} cdot C u_{2} I_{2} ) в. ( C u I_{2} ) ( mathbf{c} cdot K_{2}left[C u I_{4}right] ) D. None of the above |
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| 31 | Lead pencil contains: A. graphite B. softened leadd c. galena D. anglesite |
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| 32 | Auto-reduction is employed in the metallurgy of : A. ( H g ) в. ( A l ) c. ( T i ) D. ( Z n ) |
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| 33 | toppr Q Type your question At the point of intersection of ( A l_{2} U_{3} ) and ( M g O ) curves ( (A), triangle G^{0} ) becomes zero for the reaction, ( frac{2}{3} A l_{2} O_{3}+2 M g rightarrow+frac{4}{3} A l ) Below this point, magnesium can reduce alumina. Although thermodynamically feasible, Al is not used for reduction of ( M g O ) because: A. temperature required is very highh B. the yields of metal is very low c. the value of ( triangle G^{0} ) becomes positive D. magnesium is not used as reducing agent for any |
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| 34 | Complex formation method is used for the extraction of: ( A cdot z n ) B. Agg c. ну D. cu |
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| 35 | Question 11. What criterion is followed for the selection of the stationary phase in chromatography? Salution tinnon, nhanh. |
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| 36 | Which of the following metals are found in native state? ( A g, P t, C, S i, N, O, M g, N a, P b ) ( A cdot A g, P t, C, N, O ) B. Ag, Pt, Mg c. Ag, Pt, Pb, Mg D. Ag, Pt |
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| 37 | Gravity separation process is used for the concentration of Haematite 2. Chalcopyrite 3. Bauxite Choose the correct one from the given options. |
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| 38 | Which of the following oxides cannot be reduced to metal by carbon? This question has multiple correct options A. ( Z n O ) в. ( A l_{2} O_{3} ) c. ( C u O ) D. ( mathrm{CaO} ) |
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| 39 | In electro-refining of copper, some gold is deposited as: A. cathode mud B. electrolyte c. anode mud D. none of these |
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| 40 | Find the incorrectly matched pair. | 12 |
| 41 | Collectors are the substances which combine with sulphide ore and make them water repellant. Which of the following substance can act as collector? A. Sodium ethyl xanthate B. Sodium xenate c. Sodium pyrophosphate D. Adsorption |
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| 42 | ( underset{(text {Sulphide ore})}{boldsymbol{A}}+boldsymbol{N a C} boldsymbol{N} stackrel{boldsymbol{a i r}}{=} underset{(c o m p l e x)}{boldsymbol{B}}+ ) ( N a_{2} S stackrel{O_{2}}{longrightarrow} N a_{2} S O_{4} ) Then ( B ) is : A. Ferromagnetic B. Paramagnetic C. Linear complex D. coordination number of central atom is 4 |
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| 43 | Identify the reaction during electrolytic reduction of alumina at cathode. A ( cdot 2 H_{2} O_{2} rightarrow O_{2}+4 H^{+}+4 e^{-} ) B. ( 3 F^{-} rightarrow 3 F+3 e^{-} ) c. ( A l^{+3}+3 e^{-} rightarrow A l ) D. ( 2 H^{+}+2 e^{-} rightarrow H_{2} ) |
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| 44 | The reaction that does not define calcination is: A ( . Z n C O_{3} stackrel{Delta}{longrightarrow} Z n O+C O_{2} ) B ( cdot F e_{2} O_{3} cdot x H_{2} O stackrel{Delta}{longrightarrow} F e_{2} O_{3}+x H_{2} O ) ( mathbf{c} cdot mathrm{CaCO}_{3} cdot mathrm{MgCO}_{3} stackrel{Delta}{longrightarrow} mathrm{CaO}+mathrm{MgO}+2 mathrm{CO}_{2} ) D ( cdot 2 C u_{2} S+3 O_{2} stackrel{Delta}{longrightarrow} 2 C u_{2} O+2 S O_{2} ) |
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| 45 | Describe the role of the following in metallurgy: lime Stone in blast furnace |
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| 46 | 0.53 Assertion (A) Zone refining method is very useful for producing semiconductors. Reason (R) Semiconductors are of high purity. |
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| 47 | Which one of the following is the chief ore of copper? A . galena B. copper pyrite c. siderite D. All of the above. |
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| 48 | Assertion Reduction of ( boldsymbol{F} boldsymbol{e}_{2} boldsymbol{O}_{3}, ) with ( mathrm{CO} ) is done below ( 710^{circ} mathrm{C} ) Reason ( Delta G ) is negative at this temperature; thus,process is spontaneous. Read the above assertion and reason |
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| 49 | Chile salt petre is the nitrate mineral of A. potassium B. sodium c. calcium D. lithium |
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| 50 | Some of the reactions taking place during bessemerisation possibly are – ( boldsymbol{A}: boldsymbol{F} boldsymbol{e} boldsymbol{O}+boldsymbol{S} boldsymbol{i} boldsymbol{O}_{2} rightarrow boldsymbol{F} boldsymbol{e} boldsymbol{S} boldsymbol{i} boldsymbol{O}_{3} ) ( B: 2 F e S+3 O_{2} rightarrow 2 F e O+2 S O_{2} ) ( boldsymbol{C}: mathbf{2} boldsymbol{C u}_{2} boldsymbol{S}+mathbf{3} boldsymbol{O}_{2} rightarrow boldsymbol{2} boldsymbol{C} boldsymbol{u}_{2} boldsymbol{O}+ ) ( 2 S O_{2} ) ( boldsymbol{D}: boldsymbol{2} boldsymbol{C} boldsymbol{u}_{2} boldsymbol{O}+boldsymbol{C} boldsymbol{u}_{2} boldsymbol{S} rightarrow boldsymbol{6} boldsymbol{C} boldsymbol{u}+boldsymbol{S} boldsymbol{O}_{2} ) Select reactions actually taking place : ( A cdot A, B ) B. B, ( c cdot A, C ) D. ( c, D ) |
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| 51 | Describe the following. (i) The role of cryolite in electrometallurgy of aluminium. (ii) The role of carbon monoxide in the refining of crude nickel. |
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| 52 | The temperature of the slag zone in the metallurgy of iron using the blast furnace is: ( 1.800-1000^{circ} C ) ( 2.500-700^{circ} C ) ( 3.1200-1500^{circ} mathrm{C} ) Select the correct one from the given options. |
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| 53 | Extraction of aluminium from aluminium oxide ( left(A l_{2} O_{3}right) ) is best done by : A . electrolytic reduction of ( A l_{2} O_{3} ) B. reduction of ( A l_{2} O_{3} ) with carbon c. reduction of ( A l_{2} O_{3} ) wilh sodium D. reduction of ( A l_{2} O_{3} ) with ( c o ) |
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| 54 | In the froth floatation process, for the beneficiation of ores, the ore particles float because A. they are light B. their surface is not easily wetted by water c. they bear electrostatic charge D. they are insoluble |
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| 55 | Explain briefly the extraction of aluminium from bauxite. | 12 |
| 56 | In Mond’s process, nickel is made to react with : A. ( C ) в. ( C O ) ( mathrm{c} cdot H_{2} ) D. ( O_{2} ) |
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| 57 | Chalcacite is a type of: A. Oxide B. Sulphide c. Chloride D. Floride |
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| 58 | 9. The chief ore of aluminium is (a) Cryolite (b) Feldspar (c) Kaolin (d) Bauxite |
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| 59 | Various processes involved on the extraction of metals from their ores and refining are known as: A. concentration of ore B. enrichment of ore c. refining of ore D. metallurgy |
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| 60 | State the given statement is true or false.
Statement: Mercuric oxide is reduced |
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| 61 | The mineral of aluminium which does not contain oxygen is: A. bauxite B. diaspore c. gibsite D. cryolite |
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| 62 | The method used for the concentration of sulphide ores is: A. froth floatation B. smelting c. magnetic separatio D. gravity separation |
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| 63 | Explain the extraction of zinc from its chief ore. |
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| 64 | is the removal of oxygen for extraction of metal from ore. A. Reduction B. Electrolysis c. oxidation D. Distillation |
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| 65 | A trivalent Metal “M” occurs in nature in the form of its oxide ( M_{2} 0_{3} ). The metals is widely used in making household utensils and bodies of aircraft. (i) Identify the metal (ii) Name the chief ore of metal (iii) Write down the reaction involved during the extraction of metal with figure. |
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| 66 | The first step in the hydrometallurgical process is A. Filteration B. Electrolysis c. Reduction D. Leaching |
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| 67 | KCN forms soluble complex with silver If true enter 1 , else enter 0 |
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| 68 | Matte is a mixture of : ( mathbf{A} cdot C u_{2} S+F e S(mathrm{small} text { amount }) ) B ( cdot F e S+C u_{2} S ) (small amount) ( mathrm{c} cdot mathrm{Cu}_{2} mathrm{O}+mathrm{FeO} ) (small amount) D. ( F e O+C u_{2} O ) (small amount) |
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| 69 | Complete the following statement with an appropriate word/term to be filled in the blank space.
Froth floatation process is used for the |
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| 70 | ( B ) can be obtained from halide by van- Arkel method. This involves reaction: ( mathbf{A} cdot 2 B I_{3} frac{operatorname{Red} text { hot } mathrm{W} text { or } mathrm{Ta}_{mathrm{a}}}{text { filament }} 2 B+3 I_{2} ) B. ( 2 B C l_{3}+3 H_{2} frac{text { Red hot w or Ta }}{text { filanent }} 2 B+6 H C l ) c. both (A) and (B) D. none of the above |
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| 71 | Describe the principle involved in each of the following processes. (i) Mond process for refining of nickel (ii) Column chromatography for purification of rare relements |
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| 72 | ( F e S_{2} ) is also called because it has been mistaken for gold. A. Pure gold B. Fool’s gold c. Ferric D. None of these |
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| 73 | Which is not a compound of aluminium A. Corundum B. Ruby c. Diaspore D. Dolomite |
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| 74 | ( boldsymbol{A} boldsymbol{g}_{2} boldsymbol{S}+boldsymbol{N} boldsymbol{a} boldsymbol{C} boldsymbol{N} rightarrow boldsymbol{A} ) ( boldsymbol{A}+boldsymbol{Z} boldsymbol{n} rightarrow boldsymbol{B} ) ( B ) is a metal. Hence, ( A ) and ( B ) are respectively: A ( cdot N a_{2}left[operatorname{Zn}(C N)_{4}right], Z n ) B. ( operatorname{Na}left[A g(C N)_{2}right], A g ) c. ( operatorname{Na}left[A g(C N)_{4}right], A g ) D. ( N a_{3}left[A g(C N)_{4}right], A g ) |
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| 75 | Which of the following is a correct statement: This question has multiple correct options |
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| 76 | High purity copper metal is obtained by: A. carbon reduction B. hydrogen reduction c. electrolytic reduction D. thermite reduction |
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| 77 | It necessary for electrode b to be continuously replaced. Reason At the positive anode, oxygen gas is formed and at high temperature of the electrolysis cell it burns and oxidises away the carbon electrodes to form toxic carbon monoxide or carbon dioxide. [Note : Sketch shown is of an electrolytic cell used in the extraction of aluminium] A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion C. Assertion is correct but Reason is incorrect D. Both Assertion and Reason are incorrect |
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| 78 | Egg shell is made up of a chemical. In which of the two ores this chemical is present? A. lime stone: ( C a C O_{3} ), Dolomite ( : C a C O_{3} . M g C O_{3} ) B. lime stone: ( C a C O_{3} . M g C O_{3} ), Dolomite ( : C a C O_{3} ) c. lime stone ( : C a_{2} C O_{3} ), Dolomite ( : C a_{2} C O_{3} . M g C O_{3} ) D. None of these |
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| 79 | There are following extraction process of silver but not: A. as a side product in electrolytic refining of copper B. Parke’s process in which Zn is used to extract silver by solvent extraction from molten lead C. by reaction of silver sulphide with ( K C N ) and then reaction of soluble complex with ( mathrm{Zn} ). D. by heating ( N aleft[A g(C N)_{2}right] ) |
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| 80 | Question 9. State the role of silica in the metallurgy of copper. |
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| 81 | The most electro positive metal among the following is: A. ( Z n ) в. ( F e ) ( c . C a ) D. Na |
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| 82 | ( Z n O(S)+A rightarrow Z n(s)+B: ) A ( cdot a=H_{2}, b=O_{2} ) В ( . a=C, b=C O ) ( mathbf{c} cdot a=S, b=S O_{2} ) D. ( a=N, b=N O ) |
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| 83 | Write the reaction involved in extraction of copper from its ore by the process of electrolytic refining. |
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| 84 | Chemical formula of corundum is A ( cdot A l_{2} O_{3} cdot H_{2} O ) B. ( S i C ) c. ( A l_{2} O_{3} cdot 2 H_{2} O ) D. ( A l_{2} O_{3} ) |
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| 85 | Q. 15 Which of the following options are correct obtained by remelting pig iron with scrap iron and coke using hot air blast. (b) In extraction of silver, silver is extracted as cationic complex. (C) Nickel is purified by zone refining. (d) Zr and Ti are purified by van Arkel method. |
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| 86 | The purpose of stream of air in leaching process of ( A g_{2} S ) is to? A. Oxidises ( N a_{2} S ) formed into ( N a_{2} S_{2} O_{3} ) B. Oxidises ( N a_{2} S ) formed into ( N a_{2} S_{2} O_{4} ) c. oxidises ( N a_{2} S ) formed into ( N a_{2} O ) D. Act as catalyst |
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| 87 | Iron obtained from blast furnace is: A. Wrought iron B. Cast iron c. Pig iron D. steel |
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| 88 | Silicon is the main constituent of A. alloys B. rocks c. animals D. vegetables |
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| 89 | The oil used as frothing agent in froth floatation process is: A. coconut oil B. castor oil c. palmitic oil D. pine oil |
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| 90 | The carbon % in Pig iron? | 12 |
| 91 | Aluminium oxide is not reduced by chemical reaction since A. reducing agent contaminates B. the process pollutes the environment c. aluminium oxide is highly stable D. aluminium oxide is reactive |
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| 92 | In zone-refining method, the molten zone: A. consists of impurities only B. contains more impurity than the original metal c. contains the purified metal only D. moves to either side |
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| 93 | Which of the following pairs of elements cannot form an alloy? A. zn, Cu в. Fe, Hg c. Fe, |
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| 94 | In the electrolytic refining of copper, ( A g ) and ( A u ) are found: A. on Cathode B. on anode c. in the anodic mud D. in the cathodic mudd |
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| 95 | Leaching is commercially carried out for in the concentration of: A . galena B. argentite c. copper pyrites D. tin stone |
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| 96 | The chemical formula of feldspar is : A. ( K A l S i_{2} O_{8} ) в. ( N a_{3} A l F_{6} ) c. ( N a A l O_{8} ) D. ( K_{2} O_{4} A l_{2}left(S O_{4}right)_{4} A l(O H)_{4} ) |
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| 97 | In the cyanide extraction process of silver from argentite ore, the oxidising and reducing agents used are: A. ( O_{2} ) and ( C O ) respectively B. ( O_{2} ) and ( Z n ) dust respectively C. ( H N O_{3} ) and ( Z n ) dust respectively D. ( H N O_{3} ) and ( C O ) respectively |
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| 98 | STATEMENT-1: Silver extraction is done by dissolving its ore into cyanide solution. STATEMENT-2: In cyanide process, the silver is precipitated from soluble complex of silver of zinc-dust. A. STATEMENT-1 is True, STATEMENT-2 is True STATEMENT-2 is a correct explanation for STATEMENT- B. STATEMENT-1 is True, STATEMENT-2 is True: STATEMENT-2 is NOT a correct explanation for STATEMENT-1 c. STATEMENT-1 is True, STATEMENT-2 is False D. STATEMENT-1 is False, STATEMENT-2 is True |
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| 99 | Zone refining is a method to obtain: A. very high temperature B. ultrapure ( A l ) C. ultrapure metals D. ultrapure oxides |
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| 100 | Name the compound of nitrogen occur in earth crust? | 12 |
| 101 | During electrolytic reduction of alumina, ( mathbf{A} cdot A mid ) is formed at cathode and oxygen is formed at anode B. Al is formed at anode and oxygen is formed at cathode C. ( A I ) is formed at cathode and hydrogen is formed at anode D. Al is formed at anode and hydrogen is formed at cathode |
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| 102 | Explain the terms: (a) Leaching (b) Roasting. |
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| 103 | The advantage(s) of using carbon to reduced a number of oxides and other compounds are: This question has multiple correct options A. easy availability of coke B. low cost of carbon c. tendency of carbon to show catenation. D. presence of carbon lowers the melting point of the oxide |
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| 104 | Select correct statement: A. In the decomposition of an oxide, into oxygen and gaseous metal, entropy increases. B. Decomposition of an oxide is an endothermic change. C. To make ( Delta G^{circ} ) negative, temperature should be high enough so that ( mathrm{T} Delta S^{circ}>Delta H^{circ} ) D. All of the above are correct statements. |
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| 105 | In the cyanide process for extraction of gold and silver from ores, the cyanide solution acts as a: A. Reducing agent to reduce the gold and silver compounds present in the ores into the metallic states B. Leaching agent to bring the gold and silver into solution as cyanide complexes and thus separate these metals from the ores C. Leaching agent to dissolve all the other constituents of the ores leaving the gold and silver as metals D. Leaching agent to bring the ores into solution |
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| 106 | Concentration of which of the following ore is carried out by froth floatation process? A. Bauxite B. Chalcocite c. Haematite D. Calamine |
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| 107 | In Hall Heroult’s process, the main reagent is mixed with: A. ( B_{2} H_{6} ) B. ( C_{2} H_{6} ) c. ( N a_{3} A l F_{6} ) D. ( operatorname{si} H_{4} ) |
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| 108 | 50 Assertion (A) Nickel can be purified by Mond’s process. Reason (R) Ni (CO)4 is a volatile compound which decomposes at 460 K to give pure Ni. |
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| 109 | 21. Which of the following is a chemical method of concentration of ores? (a) Froth floatation process (b) Magnetic separation (c) Hydraulic washing (d) Leaching |
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| 110 | How is silver extracted from argentite ore? |
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| 111 | Argentite is an ore of : A . iron B. gold c. platinum D. silver |
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| 112 | Sulphur molecule exists as: ( A cdot S_{2} ) в. ( S ) c. ( S_{6} ) D. ( S_{8} ) |
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| 113 | Which of the following is NOT calcination? ( mathbf{A} cdot F e(O H)_{3} cdot x H_{2} O rightarrow F e_{2} O_{3}+H_{2} O ) B. ( C u C O_{3} cdot C u(O H)_{2} rightarrow^{2} C u O+C O_{2}+H_{2} O ) ( mathbf{c} cdot C a C O_{3} rightarrow^{C} a O+C O_{2} ) D. ( left(N H_{4}right)_{2} C O_{3} rightarrow^{2} N H_{3}+C O_{2}+H_{2} O ) |
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| 114 | Concentration by froth floatation is applicable for which of the following ores? A. ( A l_{2} O_{3} ) в. ( T e_{3} O_{4} ) c. ( T e_{2} O_{3} .3 H_{2} O ) D. ( Z n S ) |
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| 115 | toppr Q Type your question- (i) ( left.M_{(s)}+frac{1}{2} O_{2(g)} rightarrow M O_{(} sright) ) (ii) ( frac{1}{2} C_{(s)}+frac{1}{2} O_{2(g)} rightarrow frac{1}{2} C O_{2(g)} ) (iii) ( C_{(s)}+frac{1}{2} O_{2(g)} rightarrow C O_{(g)} ) ( left(text { iii) } C O_{(g)}+frac{1}{2} O_{2(g)} rightarrow C O_{2(g)}right. ) The temperature dependence of ( Delta ) G of reaction (i) to (iv) is shown in the given diagram. This is known as the Ellingham diagram. With the help of the Ellingham diagram, one can easily predict the most suitable reducing agent for the reduction of metal oxides. ( A I_{2} O_{3} ) can be reduced by carbon at a temperature of ( A cdot 30^{circ} mathrm{C} ) B ( .500^{circ} mathrm{C} ) ( mathrm{D} cdot>2500^{circ} mathrm{C} ) |
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| 116 | Use the Ellingham diagram for oxides to find: 1. If ( A I ) will reduce chromium oxide 2. At what temperature C will reduce magnesium oxide, and 3. At what temperature mercuric oxide will decompose into its elements. |
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| 117 | 2 When copper ore is mixed with silica, in a reverberatory furnace copper matte is produced. The copper matte contains (a) sulphides of copper (II) and iron (11) (b) sulphides of copper (II) and iron (III) (c) sulphides of copper (I) and iron (1) (d) sulphides of copper (1) and iron (III) onner matte is |
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| 118 | Formation of which of the sulphides is most spontaneous? A. ( H g S ) в. ( B i_{2} S_{3} ) ( c . P b S ) ( mathrm{D} cdot mathrm{CS} ) |
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| 119 | Name the method of concentration of haematite ore and explain the method. |
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| 120 | ( 18.4 mathrm{g} ) mixture of ( mathrm{CaCO}_{3} ) and ( mathrm{MgCO}_{3} ) on strongly heating gives ( 8.8 mathrm{g} ) of ( mathrm{CO}_{2} ) gas. Calculate mole percentage of ( M g C O_{3} ) in the mixture |
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| 121 | Bauxite, the ore of aluminium, is purified by which process? A. Hoope’s process B. Hall’s process c. Mond’s process D. Liquation process |
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| 122 | The element which could be extracted by electrolytic reduction of its oxide dissolved in a high temperature melt is: A. sodium B. magnesium C. flourine D. aluminium |
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| 123 | Name the reagent that is used in leaching of gold. A. carbon B. Sodium cyanide c. Carbon monoxide D. lodine |
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| 124 | Find out ( mathrm{B} ) in the given process. A ( cdot operatorname{Na}left[A l(O H)_{4}right. ) в. ( N a O H ) ( mathrm{c} cdot mathrm{H}_{2} mathrm{SO}_{4} ) D. ( A l_{2} O_{3} ) |
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| 125 | Question 1. Copper can be extracted by hydrometallurgy but not zinc. Explain. Consider the E°values of the metals and compare them. |
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| 126 | Match the following: ( begin{array}{ll}text { Column I } & text { Column II } \ text { A. Sphalerits } & text { p. } F e C O_{3} \ text { B. Malachite } & text { q. } Z n C O_{3} \ text { C. Calamine } & text { r. } N a_{3} A l F_{8} \ text { D. Cryolite } & text { s. } C u C O_{3} cdot C u(O H)_{2} \ text { E. Siderite } & text { t. } Z n Send{array} ) A. A-r B-p C-t D-q E-s B. A-t B-s C-q D-p E-r C. A-t B-r C-q D-p E-s D. A-t B-s C-q D-r E-p ( E cdot A-r B-r C-p D-t E-s ) |
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| 127 | Match the column. | 12 |
| 128 | Which of the following is a basic carbonate mineral? ¡) Malachite ii) Dolomite iii) Azurite iv) Magnesite A . i, iii and iv B. ii, iii and iv c. i and iv D. iii and iv |
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| 129 | Metal oxide can be reduced by A . ( F e ) в. ( S n ) ( c . c ) D. All of these |
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| 130 | Extraction of silver is achieved by initia complexation of the ore (Argentite) with ( X ) followed by reduction with ( Y . X ) and ( boldsymbol{Y}, ) respectively, are: A . ( C N^{-} ) and ( Z n ) B. ( C N^{-} ) and ( C u ) c. ( C l^{-} ) and ( Z n ) D. ( B r^{-} ) and ( Z n ) |
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| 131 | During extraction of metals, electrolytic refining is used to obtain pure metals. What is the electrolyte used? A. Silver salt B. Copper(II) sulphate c. sodium chloride D. Both A and B |
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| 132 | Which of the following elements can be prepared by heating the oxide above ( 400^{circ} mathrm{C} ? ) ( A cdot H g ) ( c . F e ) 3 |
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| 133 | Name the process: ( Z r+2 I_{2} stackrel{600^{circ} C}{longrightarrow} Z r I_{4} stackrel{1800^{circ} C}{longrightarrow} Z r+2 I_{2} ) Options: 1. Monds 2. Van Arkel 3. Hall 4. Bausch Enter the correct option in the form of the number |
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| 134 | Assertion ( A l_{2} O_{3} ) is converted into ( A l ) by reduction with carbon at high temp Reason Carbon has greater affinity for oxygen than aluminium 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 and Reason is correct |
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| 135 | The extraction of metals from it’s compound by electrolysis is known as A. electroplating B. electrorefining c. electrometallurgy D. extraction of metals |
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| 136 | O. 19 Common impurities present in bauxite are. (a) Cuo (b) Zno (c) Fe,03 Ans. (c. d) (d) SiO 30 |
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| 137 | Which type of ores are concentrated by froth flotation process? A. Carbonates B. Sulphides c. oxides D. Phosphates |
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| 138 | ( boldsymbol{A} boldsymbol{g}_{2} boldsymbol{S}+boldsymbol{N} boldsymbol{a} boldsymbol{C} boldsymbol{N} longrightarrow(boldsymbol{A}),(boldsymbol{A})+ ) ( boldsymbol{Z} boldsymbol{n} longrightarrow(boldsymbol{B}) ) (B) is a metal. Hence (A) and (B) are: A ( cdot operatorname{Na}_{2}left[operatorname{Zn}(C N)_{4}right], Z n ) B . ( N a_{2}left[A g(C N)_{2}right], A g ) c. ( N a_{2}left[A g(C N)_{4}right], A g ) D. ( N a_{3}left[A g(C N)_{4}right], A g ) |
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| 139 | Assertion Extraction of iron metal from iron oxide ore is carried out by heating with coke. Reason The reaction ( F e_{2} S O_{3} Delta F e(s)+ ) ( mathbf{3} / mathbf{2} boldsymbol{O}_{mathbf{2}}(boldsymbol{g}) ) is a spontaneous process at standarde condition. Read the above assertion and reason and choose the correct option regarding ¡t A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is correct but Reason is incorrect D. Both Assertion and Reason are incorrect |
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| 140 | In the Hall-Heroult process, aluminium is formed at the cathode. The cathode is made out of: A. platinum B. carbon c. pure aluminium D. copper |
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| 141 | The earthy impurities present in the mineral are called: A . flux B. slag c. gangue D. refractory material |
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| 142 | The reducing agent in thermite process is (a) Al (b) Mg (c) Bao2 (d) Mno, |
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| 143 | Explain the purification of sulphide ore by Froth floatation method. | 12 |
| 144 | The extraction of metals from oxide ores may involve: This question has multiple correct options A. reduction with carbon B. reduction with aluminium c. electrolyte reduction D. reduction with ( c 0 ) |
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| 145 | Extraction of gold (Au) involves the formation of complex ions ( X ) and ( Y ) Gold ore ( frac{text { Roasting }}{C N^{-}, H_{2} O, O_{2}} H O^{-}+X stackrel{Z n}{longrightarrow} ) ( boldsymbol{Y}+boldsymbol{A} boldsymbol{u} ) X and Y respectively are : A ( cdot A u(C N)_{2}^{-} ) and ( Z n(C N)_{4}^{2} ) B . ( A u(C N)_{4}^{3-} ) and ( Z n(C N)_{4}^{2} ) c. ( A u(C N)_{3}^{-} ) and ( Z n(C N)_{6}^{4} ) D. ( A u(C N)_{4}^{-} ) and ( Z n(C N)_{3} ) |
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| 146 | Which of the following minerals does not contain Al? A. Mica B. cryolite c. Felspar D. Flourospar |
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| 147 | 0.7 Brine is electrolysed by using inert electrodes. The reaction at anode is ……… (a) C (aq) C12 (8) +e; Epall = 1.36 V (b) 2H20 (1) O2(g) + 4H+ + 4e; Ecell = 1.23 V (c) Na+ (aq)+ e Na(s); E = 2.71 V (d) H+ (aq) + e + H2(8); Eeell = 0.00 V |
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| 148 | Anaemia is caused by the deficiency of : A. Iron B. zinc c. lodine D. Calcium |
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| 149 | Blister Cu contains about: A. ( 60 % ) Cu B. 90% Cu c. ( 98 % ) си D. ( 100 % ) Cu |
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| 150 | Write the principle behind the froth floatation process. What is the role of collectors in this process? | 12 |
| 151 | How are lanthanides extracted from monazite sand? |
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| 152 | Na and Al are the examples of two metals which are manufactured by the electrolysis of their fused salts. If true enter 1 , else enter 0 . |
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| 153 | Which of the following is dolomite: A ( cdot C a C O_{3} cdot M g C O_{3} ) в. ( C u_{2} S, ) Fe( _{2} S_{3} ) c. ( C d S ) D. ZnS |
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| 154 | Metals extracted by electrolysis of their fused salts are : A. highly electropositive B. highly electronegative c. Both A and B D. None of the above |
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| 155 | What happens when silver is leached with ( N a C N ) in the presence of air? |
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| 156 | is the most abundant element in the earth’s crust. |
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| 157 | In the extraction of aluminium the electrolyte is: A. fused cryolite with felspar B. fused cryolite with fluorspar c. pure alumina in molten cryolite with fluorospar D. pure alumina with bauxite and molten cryolite |
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| 158 | To dissolve argentite ore which of the following is used? A ( cdot operatorname{Na}left[operatorname{Ag}(C N)_{2}right] ) в. ( N a C N ) c. ( N a C l ) D. HCl |
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| 159 | STATEMENT-1: Magnesium can be prepared by the electrolysis of aq. ( M g C l_{2} ) STATEMENT-2: The reduction potential of ( M g^{2+} ) is much lower than that of ( H^{+} ) A. STATEMENT-1 is True, STATEMENT-2 is True: STATEMENT-2 is a correct explanation for STATEMENT- B. STATEMENT-1 is True, STATEMENT-2 is True STATEMENT-2 is NOT a correct explanation for STATEMENT-1 c. STATEMENT-1 is True, STATEMENT-2 is False D. STATEMENT-1 is False, STATEMENT-2 is True |
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| 160 | An ore on heating in air forms ( S O_{2} ) State the process that will be used for its concentration. A. Hydrautic washing B. Magnetic separation c. Froth floatation D. None of the above |
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| 161 | Question 19. How is leaching carried out in case of low grade copper ores? |
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| 162 | Main ore of aluminium is: A. ( A l_{2} S ) B. Bauxite c. cinnabar D. Aluminium glance |
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| 163 | The ore that is concentrated by the froth floatation process is: A. chalcopyrites B. cryolite c. cuprite D. calamine |
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| 164 | Question 7. The mixture of compounds A and B is passed through a column of Al2O3 by using alcohol as eluant. Compound A is eluted in preference to compound B. Which of the compounds A or B, is more readily adsorbed on the column? and I the |
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| 165 | In case of Hall’s process applied on reduction of ( A l_{2} O_{3} ) to ( A l ) can be done by using: A. Cathode – Al, Anode – Graphite B. Cathode – Graphite, Anode – Graphite c. cathode – Graphite, Anode – steel D. Cathode – Steel, Anode – Graphite |
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| 166 | Redox reaction involves reaction between: A. The electrolytic cell when fused ( M g C l_{2} ) is subjected to electrolysis B. When fused ( M g C l_{2} ) is heated C. When fused ( M g C O_{3} ) is strongly heated D. None of the above |
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| 167 | Matrix is defined as: A. the unwanted foreign material present in the ore B. the flux added to remove the unwanted impurities from ore C. the slag formed as a result of the reaction of flux with gongue D. the material used in the reduction of metal oxide to metal |
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| 168 | What is refining of metals? Explain with diagram the method of electrolysis by which copper is purified. |
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| 169 | The soluble complex formed during the extraction of silver from glance cyanide process is: A ( cdot operatorname{Na}_{2}left[operatorname{Zn}(C N)_{4}right] ) В ( cdot_{N a_{2}}left[Z n(C N)_{6}right] ) c. ( _{N a_{4}}left[Z n(C N)_{6}right] ) D. None of these |
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| 170 | Chalcogens are: A. hydrocarbons B. ore forming elements C. oxide forming elements D. those having ability to catenate |
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| 171 | When 1 mol of pure ( A g_{2} C O_{3} ) is strongly heated, calculate the weight of residue obtained in ( mathfrak{g m} ) | 12 |
| 172 | In electrolytic refining of any metal impure metal is taken as A. anode B. cathode c. solution D. both B and C |
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| 173 | Selection of temperature to carry out a reduction process depends so as to make : A. ( Delta G ) negative B. ( Delta G ) positive c. ( Delta H ) negative D. ( Delta H ) positive |
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| 174 | In Hall-Heroult process ( C O_{2} ) is released at ? |
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| 175 | What is the the actual reducing agent of haematite in blast furnace | 12 |
| 176 | Froth floatation process is used for the : A. Oxide ores B. Sulphide ores c. chloride ores D. All of these |
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| 177 | Question 3. The reaction, Cr2O3(s) + 2Al(s) – A1,03 +2Cr; (AG° = – 421 kJ) is thermodynamically feasible as is apparent from the Gibbs energy value. Why does it not take place at room temperature! |
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| 178 | ( F e C r_{2} O_{4}(text { Chromite }) ) is a good source of chromium and its compound like ( N a_{2} C r O_{4} ) and ( N a_{2} C r_{2} O_{7} ) I. ( boldsymbol{F e} boldsymbol{C r}_{2} boldsymbol{O}_{4}+boldsymbol{N a O H}+boldsymbol{a i r} longrightarrow ) ( (boldsymbol{A})+boldsymbol{F} boldsymbol{e}_{2} boldsymbol{O}_{3} ) II. ( (boldsymbol{A})+(boldsymbol{B}) longrightarrow boldsymbol{N} boldsymbol{a}_{2} boldsymbol{C r}_{2} boldsymbol{O}_{7} ) ( mathrm{III} . N a_{2} C r_{2} O_{7}+X stackrel{triangle}{longrightarrow} C r_{2} O_{3} ) IV. ( boldsymbol{C r}_{2} boldsymbol{O}_{3}+boldsymbol{Y} stackrel{Delta}{longrightarrow} boldsymbol{C r} ) Compounds ( (A) ) and ( (B) ) are: A ( cdot N a_{2} C r O_{4}, H_{2} S O_{4} ) в. ( N a_{2} C r_{2} O_{7}, H C l ) c. ( N a_{2} C r O_{6}, H_{2} S O_{4} ) D. ( N a_{4}left[F e(O H)_{6}right], H_{2} S O_{4} ) |
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| 179 | Assertion Extraction of gold from its native ore involves leaching the metal ore with dilute solution of NaCN in presence of air. Reason This is an oxidation reaction and leads to the formation of a soluble complex. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion C. Assertion is correct but Reason is incorrect D. Assertion is incorrect but Reason is correct |
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| 180 | Which of these is not an ore of Iron? A . Haematite B. Limonite c. cassiterite D. Magnetite |
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| 181 | From the following identify the correct ones. This question has multiple correct options A ( cdot F e_{2} O_{3}+3 C O rightarrow 2 F e+3 C O_{2} ) в. ( Z n O+C rightarrow Z n+C O ) ( mathbf{c} cdot C a_{3}left(P O_{4}right)_{2}+C rightarrow P ) ( mathbf{D} cdot P b O+C rightarrow P b ) |
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| 182 | Question 4. Is it true that under certain conditions, Mg can reduce Al2O3 and Al can reduce MgO? What are those conditions? Consider the Ellingham diagram for Al and Mg, to find the conditions in which they act as reducing agents. |
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| 183 | Assertion van Arkel method is used for refining of zinc. Reason In this method impure metal is evaporated to obtain the pure metal as distillate. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is correct but Reason is incorrect D. Both Assertion and Reason are incorrect |
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| 184 | The reaction(s) which (do) not occur in the reduction zone in the extraction of iron from haematite ore is (are):- This question has multiple correct options A. ( F e_{2} O_{3}+C O rightarrow 2 F e O+C O_{2} ) в. ( F e O+C O rightarrow F e+C O_{2} ) ( mathbf{c} cdot F e_{2} O_{3}+3 C rightarrow 2 F e+3 C O ) D. ( C a O+S i O_{2} rightarrow C a S i O_{3} ) |
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| 185 | What is amalgam? | 12 |
| 186 | Leaching is a process of : A. reduction B. concentration C . refining D. oxidation E. none of these |
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| 187 | Which one of the following ore is not concentrated by froth floatation process? A. Copper pyrites B. Galena c. Pyrolusite D. zinc blende |
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| 188 | Assertion In the extraction of aluminium by electrolysis it is necessary to renew the anode periodically. Reason Oxygen gas is formed and at high temperature of the electrolysis cell it burns and oxidises away the carbon electrodes to form toxic carbon monoxide or carbon dioxide A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion C. Assertion is correct but Reason is incorrect D. Both Assertion and Reason are incorrect |
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| 189 | 0.27 Why is an external emf of more than 2.2V required for the extraction OT Cl, from brine? 2C-a + 2HOD |
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| 190 | Define the term metallurgy | 12 |
| 191 | 7. In fractional distillation, hydrocarbons with the … (highest/lowest) boiling points condense first. |
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| 192 | 11. Bronze is a mixture of (a) Pb+ Sn (c) Cu+Zn (b) Cu + Sn (d) Pb + Zn |
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| 193 | Ellingham diagram is used for: A. Reduction B. Electrolysis c. zone refining D. van-Arkel |
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| 194 | Which of the following metal oxides are reduced by self reduction method? This question has multiple correct options ( mathbf{A} cdot C u_{2} O ) в. ( P b O ) c. ( H g O ) D. ( mathrm{CaO} ) |
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| 195 | Which one of the following is the main process for extraction nickel in the pure form? A. Vapour phase refining B. zone refiningg c. Electrolysis D. Solvent extraction |
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| 196 | Which of the following element is purified by vapour phase refining? A . ( F e ) в. ( Z r ) c. ( C u ) D. ( A u ) |
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| 197 | The impurity in white bauxite is: A. ( F e O ) в. ( F e_{2} O_{3} ) ( mathrm{c} cdot operatorname{sio}_{2} ) D. ( A l C l_{3} ) |
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| 198 | The method of zone refining of metals is based on the principal of: A. Greater mobility of the pure metal than that of the impurity B. Higher melting point of the impurity than that of the pure metal C. Greater noble character of the solid metal than that of the impurity D. Greater solubility of the impurity in the molten state than in the solid |
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| 199 | Hydraulic washing is based on the differences in: A. special gravities of the ore and gangue particles B. special density of the ore and gangue particles c. special viscosity of the ore and gangue particles D. both ( A ) and ( B ) |
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| 200 | Q20. What is the basic principle of chromatography? | 12 |
| 201 | The formula of Dolomite is : A. ( M g C O_{3} . C a C l_{2} ) в. ( M g C O_{3} . C a C O_{3} ) c. ( M g C O_{3} . ) CaS ( O_{4} ) D. ( M g C l_{2} . C a C O_{3} ) |
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| 202 | The ore chromite is: A ( cdot F e C r_{2} O_{4} ) в. ( operatorname{CoCr}_{2} mathrm{O}_{3} ) ( mathbf{c} cdot operatorname{Cr} F e_{2} O_{4} ) D. ( F e C r_{2} O_{3} ) |
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| 203 | Which mineral has been named incorrectly? A. Bauxite ( : quad A l_{2} O_{3} cdot 2 H_{2} O ) B. Corundum : ( quad A l_{2} O_{3} ) c. Cryolite : 3 NaF ( cdot ) AIF( _{3} ) D. Felspar : ( quad B e_{3} A l_{2} S i_{6} O_{18} ) |
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| 204 | The metal extracted by leading with a cyanide is: A . ( A l ) в. ( N a ) ( c . A g ) D. ( C u ) |
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| 205 | Iron can be purified by the method of liquation. A . True B. False |
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| 206 | Extraction of chlorine from brine is based on: A. reduction B. displacement c. oxidation D. evaporation |
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| 207 | You must have seen tarnished copper vessels being cleaned with lemon or tamarind juice. Explain why these sour substances are effective in cleaning the vessels. |
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| 208 | after Question 14. Write down the reactions taking place in Blast furnace related to the metallurgy of iron in the temperature range 500-800 K. |
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| 209 | Metals more reactive than carbon are usually extracted by A. Pyrolysis B. Electrolysis c. Fractional distillation D. Filteration |
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| 210 | Extraction of aluminium from oxide ( left(A l_{2} O_{3}right) ) is best done by: A . Electrolytic reduction of ( A l_{2} O_{3} ) B. Reduction of ( A l_{2} O_{3} ) with carbon c. Reduction of ( A l_{2} O_{3} ) with sodium D. Reduction of ( A l_{2} O_{3} ) with ( c 0 ) |
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| 211 | What is the type of chemical reaction carried out after roasting in order to obtain zinc? A. reduction B. oxidation c. both ( A ) and ( B ) D. none of the above |
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| 212 | Froth flotation process which is used for the concentration of sulphide ore: ( A . ) is based on the difference in wettability of different minerals B. uses sodium ethyl xanthate, ( C_{2} H_{5} O C S_{2} N a ) as collector C. uses NaCN as depresent in the mixture of ZnS and PbS when ZnS forms soluble complex and PbS forms froth D. All of the above are correct |
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| 213 | ( H_{2} ) is not widely used as the reducing agent in metallurgic process because: This question has multiple correct options A. many metals react with ( H_{2} ) at elevated temperature forming hydrides B. there is a risk of explosion from ( H_{2} ) and ( O_{2} ) present in the air C . reducing power of ( H_{2} ) does not increase with temperature D. reducing power of ( H_{2} ), increases with temperature |
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| 214 | In the process of extraction of gold, the following reaction takes place: Roasted gold ore ( +boldsymbol{C} boldsymbol{N}^{-}+boldsymbol{H}_{2} boldsymbol{O} rightarrow ) ( [boldsymbol{X}]+boldsymbol{O H}^{-} ) ( [boldsymbol{X}]+boldsymbol{Z} boldsymbol{n} rightarrow[boldsymbol{Y}]+boldsymbol{A} boldsymbol{u} ) Identify the compounds ( [mathrm{X}] ) and ( [mathrm{Y}] ) A ( cdot[X]=left[A u(C N)_{2}right]^{-},[Y]=left[Z n(C N)_{4}right]^{2-} ) B . ( [X]=left[A u(C N)_{4}right]^{3-},[Y]=left[Z n(C N)_{4}right]^{2-} ) C ( cdot[X]=left[A u(C N)_{2}right]^{-},[Y]=left[Z n(C N)_{6}right]^{4} ) D ( cdot[X]=left[A u(C N)_{4}right]^{-},[Y]=left[Z n(C N)_{6}right]^{2} ) |
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| 215 | Ores contain a large amount of impurities, which is called as: A . ore B. gangue c. dust D. particulate |
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| 216 | Which of the following statement is not correct about Ellingham diagram? A. ( Delta G ) increases with an increase in temperature B. It consists of plots of ( Delta_{f} G^{circ} ) vs ( T ) for formation of oxides C. A coupling reaction can be well expressed by this diagram D. It express the kinetics of the reduction process |
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| 217 | Match the following: Biodegradable ( mathbf{F} ) (i) ( quad(p) quad ) Hydroxybuta B p polymer poing (ii) Phenol 2-chlorobuta-1 (ii) Bakelite (ig) Phenol Neoprene (iv) Glyptal (r) 2-chlore diene (iii) 2-chlo diene ( mathbf{A} cdot i-p, i i-q, i i i-r, i v-s ) B ( . i-q, i i-p, i i i-r, i v-s ) ( mathbf{c} cdot i-p, i i-q, i i i-s, i v-r ) D. ( i-s, i i-r, ) ii ( i-p, i v-q ) |
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| 218 | The correct statement is : A. leaching of bauxite using concentrated ( N a O H ) solution gives sodium aluminate and sodium silicate B. The blistered appearance of copper during the metallurgical process is due to the evolution of ( C O_{2} ) C . pig iron is obtained from cast iron D. the Hall-Heroult process is used for the prodeuction of aluminium and iron. |
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| 219 | Steel is heated to below red heat and then, cooled slowly. The process refers to: A. hardening B. annealing c. tempering D. nitriding |
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| 220 | 8. Calcination is the process of heating the ore (a) In a blast furnace (b) In absence of air (c) In presence of air (d) None of these |
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| 221 | Select incorrect reduction process: ( mathbf{A} cdot 2left[A g(C N)_{2}right]^{-}+Z n rightarrowleft[Z n(C N)_{4}right]^{2-}+2 A g ) в. ( C u O+H_{2} rightarrow C u+H_{2} O ) c. ( Z n O H_{2} rightarrow Z n+H_{2} O ) D. ( M g O+C rightarrow M g+C O ) |
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| 222 | Which is not a mineral of aluminium? A. Anhydrite B. Bauxite c. corundum D. Diaspore |
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| 223 | The chemical composition of the slag formed during smelting process is : A ( cdot ) Cusio ( _{3} ) в. Fesi Оз( _{3} ) ( mathrm{c} cdot operatorname{casi} O_{3} ) D. ( C u_{2} O . S i O_{2} ) |
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| 224 | Match the following metals listed in Column I with extraction processes listed in Column II: |
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| 225 | Bauxite is concentrated by: A. Chemical method B. Roasting C. Magnetic separation D. Froth flotation process |
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| 226 | Electrolysis of fused ( K C l . M g C l_{2} ) gives: A. potassium only B. magnesium only c. magnesium and chlorine D. potassium, magnesium and chlorine |
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| 227 | Write the chemical reactions related to Mond process for refining nickel metal. |
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| 228 | ( A l_{2} O_{3} ) is chemical formula of : A . cryolite B. corundum c. kaolin D. bauxite |
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| 229 | In van Arkel method, if ( I_{2} ) is introduced over impure metal at ( 1700 mathrm{K} ), which of the following will occur? A. lodide of the metal is formed B. No reaction takes place c. Impurities react with iodine D. Metal doesn’t react |
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| 230 | In the leaching of ( A g_{2} S ) with ( N a C N, ) a stream of air is also passed. It is because of: This question has multiple correct options |
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| 231 | Which of these is obtained by electrolytic reduction of its compound? A. ( C u ) в. ( A u ) ( mathrm{c} cdot M g ) D. ( B i ) |
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| 232 | The recovery of silver from the solutions used in developing and fixing photographic film and prints present just such a problem. Silver is an expensive metal, and the recovery is profitable. Moreover, if not recovered, the silver ions would constitute and undesirable pollutant in water supplies The equation in which silver recovered from such solution is ( : A g_{2} C O_{3} stackrel{Delta}{rightarrow} ) ( 2 A g+C O_{2}+frac{1}{2} O_{2} ) |
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| 233 | With respect to an ore, Ellingham diagram helps to predict the feasibility if its: A. vapour phase refining B. zone refiningg c. electrolysis D. thermal reduction |
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| 234 | Metals can be recovered from their ores by chemical methods. A. True B. False |
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| 235 | Cassiterite is concentrated by Froth flotation process 2. Magnetic separation 3. Distillation method 4. Calcination method |
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| 236 | Van Arkel method of purification of metals involves converting the metal to ( a: ) A. volatile unstable compound B. volatile stable compound c. non-volatile stable compound D. None of the above |
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| 237 | The chemical formula for copper pyrites is : A. ( C u F e S_{2} ) в. ( C u_{2} S ) ( mathbf{c} cdot C u_{2} O ) D. ( C u C O_{3} cdot C u(O H)_{2} ) |
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| 238 | The extraction of metal from the ore is : A. an oxidation process B. a reduction process C . a hydration process D. a neutralisation process |
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| 239 | Outline the principles of refining of metals by the following methods: (i) Zone refining (ii) Vapour phase refining |
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| 240 | When an inert atmosphere is needed for a metallurgical process, nitrogen is frequently used. However, in the reduction of ( T i C l_{4} ) by magnesium, helium is used. This is because ( N_{2} ) can combine with |
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| 241 | Phosphoric acid is prepared on large scale from A. phosphorus B. dolomite c. phosphorite D. malachite |
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| 242 | Which of the following statement(s) is/are correct”? This question has multiple correct options A. The chemical processes in the production of steel from haematite ore involve reduction followed by oxidation. B. In Hall-Heroult process, the electrolyte used is a molten mixture of alumina and cryolite or fluorspar. C. Lead is extracted from its chief ore galena by both carbon reduction as well as self reduction, D. Haematitic, cassiterite, and argentite are oxide ores. |
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| 243 | The diagram shows the sketch of an electrolytic cell used in the extraction of aluminium. At which electrode (A or B) is the aluminium formed? A. A (Cathode) B. B (Anode) c. At both A and B D. Cannot be determined |
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| 244 | Zone refining method is used for refining: A . ( A l ) в. ( G e ) c. ( C u ) D. ( F e ) |
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| 245 | Observe the following statements regarding purification of bauxite: I. During Hall’s process, silica is removed as Si (vapour). II. Bauxite ore contaminated with ( F e_{2} O_{3} ) is purified in Baeyer’s process. III. During Serpeck’s process, ( A l N ) is formed. A. I, II and III are correct B. Only I and II are correct c. only land III are correct D. Only II and III are correct |
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| 246 | Out of the following ores, how many ores do not contain more than one metal in their composition. Argentite, Barytes, Magnesite, Fluorspar, Carnalite, Dolomite, Chalcocite, Asbestos, Calamine. ( A cdot 6 ) B. 4 ( c cdot 5 ) ( D ) |
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| 247 | In Mac-Arthur Forrest method, silver is extracted from solution of ( N aleft[A g(C N)_{2}right] ) by the use of A . ( F e ) в. ( M g ) c. ( C u ) D. ( Z n ) |
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| 248 | Assertion Froth-flotation process is used to concentrate sulphide ores. Reason There is difference in the wettability of different minerals. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion C. Assertion is correct but Reason is incorrect D. Assertion is incorrect but Reason is correct |
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| 249 | ( x, y, ) and ( z ) in the following processes are respectively:- (i) ( P_{2} O_{5}+x rightarrow C a_{3}left(P O_{4}right)_{2} ) (ii) ( 2 C u_{2} O+C u_{2} S rightarrow y+S O_{2} ) (iii) ( boldsymbol{F e}_{2} boldsymbol{O}_{3}+boldsymbol{3} boldsymbol{C O} rightarrow boldsymbol{z}+boldsymbol{3} boldsymbol{C O}_{2} ) A. 3 Ca, ( C u S O_{4} ), Fe B . ( 3 C a(O H)_{2}, ) 6Си,Fео c. ( 3 C a O, 6 C u, 2 F e ) D. ( 3 mathrm{CaO}_{2} ), cus, Feo |
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| 250 | 18 carat gold is ……….. % pure. | 12 |
| 251 | Which of the following match are incorrect? (a) Goldschmidt aluminothermite process ( -C r_{2} O_{3} ) (b) Mac Arther cyanide process – ( boldsymbol{F e} ) (c) Mond process – Ni (d) Van Arkel process – ( A u ) A ( cdot ) a, B. c, d ( c cdot b, d ) D. a, |
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| 252 | Which of the following metal is refined by distillation method? A. zinc B. Iron c. Tin D. copper |
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| 253 | Write reactions involved in extraction of silver from it’s ore by leaching process. 0-nitrophenol is more acidic than 0 cresol; Explain. |
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| 254 | 15. The rocky material present in ore is known as (a) Gangue (b) Flux (c) Slag (d) None of these |
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| 255 | 10. Electrolytic reduction method is used in the extraction of (a) Highly electronegative elements (b) Highly electropositive elements (c) Transition metals (d) Noble metals |
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| 256 | Earthly particles in an ore are removed from heavier metal ore using water in: This question has multiple correct options A. levigation B. hydraulic washing c. leaching D. gravity separation |
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| 257 | Which of the given metal oxides is having minimum thermal decomposition temperature? A. Cao B. FeO ( c . ) Pbo D. MgO |
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| 258 | Outline the principles behind the refining of metals by the following methods: (i) Zone refining method (ii) Chromatographic method |
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| 259 | The idea of froth floatation method came from a person ( X ) and this method is related to the process ( Y ) of ores. ( X ) and Y, respectively, are: A. fisher woman and concentration B. washer man and reduction c. washer woman and concentration D. fisher man and reduction |
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| 260 | Explain Hall-Heroult method of obtained pure aluminium from alumina with figure. |
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| 261 | Copper matte contains ( mathbf{A} cdot C u_{2} O, C u_{2} S ) ( mathbf{B} cdot C u_{2} O, F e S ) ( mathbf{c} cdot C u_{2} S, F e S ) D. ( C u_{2} S, F e O ) |
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| 262 | Distillation under reduced pressure is used to purify liquids which: A. are highly volatile B. have high boiling points C. are explosives D. decomposes below their boiling points |
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| 263 | Which of the following reduction processes are correct? This question has multiple correct options A ( cdot F e_{2} O_{3}+C^{text {Reduction}} F e ) B . ( Z n O+C stackrel{text {Reduction}}{longrightarrow} ) Zn ( mathrm{c} cdot operatorname{Sn} mathrm{O}_{2}+C^{text {Redution}} S n ) D ( cdot P b O+C stackrel{text {Reduction}}{rightarrow} P b ) |
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| 264 | Gold ore is concentrated by leaching with A. sodium cyanide in presence of air. B. sodium cyanide in absence of air c. sodium hydroxide in presence of air D. sodium hydroxide in absence of air |
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| 265 | Silver can be obtained from silver glance by: A. from floatation followed by polling B. leaching by ( N a C N ) followed by thermal reduction C . leaching by ( left(N a C N+O_{2}right) ) followed cupellation D. None of these |
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| 266 | PUrduUHUL sido Slag Sha conve Q. 24 In which of the following method of purification, me its volatile compound which is decomposed to give pure metal: (a) Heating with stream of carbon monoxide (b) Heating with iodine (c) Liquation (d) Distillation |
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| 267 | Aluminium and copper are extracted from their oxide and sulphide ores respectively. Which of the following is correct? I. Copper is extracted by the auto reduction of copper oxide by copper sulphide. II. Aluminium cannot be obtained by chemical reduction due to its strong affinity for oxygen. III. In electrometallurgy of ( A l ), graphite is used as cathode to avoid reoxidation of ( A l ) into ( A l_{2} O_{3} ) by preventing formation of ( boldsymbol{O}_{2} ) IV. Sulphide ores of copper are difficult to be reduced than the oxide ores. A. ( I, I I, I V ) B. II and III c. ( I I I ) D. II and ( I V ) |
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| 268 | Sulphide ores of metals are usually concentrated by froth floatation process. Which one of the following sulphide ores offers an exception and is concentrated by chemical leaching? A. Argentite B. Galena c. copper pyrite D. sphalerite |
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| 269 | Which of the following statements are correct? This question has multiple correct options A. The process of producing a hard coating of iron nitride on the surface of steel is called nitriding. B. The process of producing a thin coating of iron carbide on the surface of mild steel is called case hardening. C. Quenched steel is produced by healing steel to redness and allowing it to cool slowly. D. Stainless steel is produced by heating wrought iron in molten chromium, |
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| 270 | The diagram shows the sketch of an electrolytic cell used in the extraction of aluminium. What is the substance of which the electrodes ( A ) and ( B ) are made? A. Carbon and graphite B. Zinc and copper c. copper and iron D. None of the above |
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| 271 | Assertion Zone refining method is used to produce pure metals which are used as semiconductors. Reason Semiconductors are used in highly pure form. A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion c. Assertion is correct but Reason is incorrect D. Both Assertion and Reason are incorrect |
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| 272 | Explain Mond’s process used for refining of nickel. | 12 |
| 273 | Select the correct statement. (a) A mineral can not be an ore (b) Allore can not be a mineral (c) Allores are minerals (d) All minerals are ores |
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| 274 | Assertion In the electrolytic reduction of ( A l_{2} O_{3} ) cryolite is used. Reason Cryolite is an ore of aluminium. 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 and Reason is correct. |
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| 275 | The slag formed in the extraction of iron from haematite in the blast furnace is: A ( . F e S i O_{3} ) в. ( operatorname{casi} O_{3} ) ( mathbf{c} cdot M g S i O_{3} ) D. ( C a_{3}left(P O_{4}right)_{2} ) |
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| 276 | 41 How are metals used as semiconductors refined? What is the principle of the method used like germanium, silicon etc? tala of bichard inductor or refined by |
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| 277 | In the extraction of iron, the most preferred ores are : A. hematite and limonite B. copper pyrites an dsiderite c. magnetite and iron pyrites D. limonite and copper pyrites |
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| 278 | Black Jack is a sulphide ore. A. True B. False |
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| 279 | The process of zone refining is used in the purification of : A . ( A l ) в. ( G e ) c. ( C u ) D. ( A g ) |
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| 280 | Haemoglobin in the blood cells mainly contains: A. Iron B. copper c. zinc D. Silver |
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| 281 | Which of the following technique uses high temperature to convert ore into raw metals? A. Pyrometallurgy B. Hydrometallurgy c. Both a and D. None of above |
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| 282 | The process of carrying out the reduction of metal oxides by heating with coke is termed as: A. Roasting B. Smelting c. zone refining D. ore dressing |
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| 283 | Formation of ( N i(C O)_{4} ) and subsequent its decomposition into Ni and CO (recycled) makes the basis of Monds process ( N i+4 C O stackrel{T_{1}}{rightarrow} N i(C O)_{4} stackrel{T_{2}}{longrightarrow} ) ( N i+4 C O ) ( T_{1} ) and ( T_{2} ) are: A ( cdot 100^{circ} mathrm{C}, 50^{circ} mathrm{C} ) B . ( 50^{circ} mathrm{C}, 100^{circ} mathrm{C} ) c. ( 50^{circ} mathrm{C}, 230^{circ} mathrm{C} ) D. ( 230^{circ} mathrm{C}, 50^{circ} mathrm{C} ) |
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| 284 | Match list I with list II and select the correct answer using the codes given below the lists. List I List II I. Cyanide e Ge and e process A. Ultrapure ( | ) Floatation process Pine oil B. III. Electrolytic reduction C. Extraction of ( A l ) Iv. Zone refining D. Extraction of f ( A u ) ( mathbf{A} cdot I-C, I I-A, I I I-D, I V-B ) B . ( I-D, I I-B, I I I-C, I V-A ) ( mathbf{c} cdot I-C, I I-B, I I I-D, I V-A ) D . ( I-D, I I-A, I I I-C, I V-B ) |
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| 285 | In the process of extraction of gold, 1.) Roasted Au ore ( +boldsymbol{C} boldsymbol{N}_{(a q)}^{-}+boldsymbol{O}_{2} longrightarrow ) ( [boldsymbol{X}]+boldsymbol{N} boldsymbol{a} boldsymbol{O} boldsymbol{H} ) 2.) ( [boldsymbol{X}]+boldsymbol{Z} boldsymbol{n} longrightarrow[boldsymbol{Y}]+boldsymbol{A} boldsymbol{u} ) A ( cdot X=left[A u(C N)_{2}right]^{-}, Y=left[Z n(C N)_{4}right]^{2} ) B . ( X=left[A u(C N)_{4}right]^{2-}, Y=left[Z n(C N)_{4}right]^{2} ) c. ( X=left[A u(C N)_{2}right]^{-}, Y=left[Z n(C N)_{6}right]^{4-} ) D. ( X=left[A u(C N)_{4}right]^{-}, Y=left[Z n(C N)_{4}right]^{2} ) |
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| 286 | Question 5. How do we separate two sulphide ores by froth floatation method? Explain with an example. |
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| 287 | The formula of cryolite is : A. ( A l_{2} O_{3} .2 H_{2} O ) в. ( A l O_{2} .2 H_{2} O ) c. ( N a_{3} A l F_{6} ) D. ( K A l S i_{3} O_{8} ) |
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| 288 | The process by which impure metals are purified electrolytically is called as A. electrorefining B. electroplating ( c cdot ) both D. none of these |
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| 289 | Which of the following is not a method of extraction of metals? A. Enrichment of ore B. Refining c. Magnetic separation D. None of the above |
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| 290 | How do we separate two sulphide ores by froth floatation method? A. By using excess of pine oil. B. By adjusting proportion of oil to water or using depressant. C. By using collectors and froth stabilities like xanthates. D. By using some solvent in which one of the sulphides is soluble. |
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| 291 | The device known as prolong is used in the extraction of : ( A cdot z n ) B. Agg ( c cdot c u ) D. Fe |
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| 292 | Question 23. The choice of a reducing agent in a particular casu depends on thermodynamic factor. How far do you agree with this statement Support your opinion with two examples. |
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| 293 | Which of the following species is desirable substance in extraction of copper but not in extraction of iron? A ( cdot ) Casio в. Fesi Оз( _{3} ) ( mathrm{c} cdot operatorname{sio}_{2} ) D. coke |
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| 294 | The process of purification of metals is represented by the following scheme ( $ $ ) Ti ( 1,+|, 2|_{-} 2 mid, ) loverset ( left{250^{wedge}{text { lcirc }} Cright} ) {ᅵrightarrow ( } ) ।. Til ( _{-} ) 4) , loverset ( {1400 text { wedge }{text { lcirc }} ) 3), Jbegin {matrix Jill pure lend ( {text { matrix }} backslash_{,+} backslash, 1_{-} 2 $ $ ) A. cupellation B. poling c. electrolytic refiningg D. van-Arkel method |
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| 295 | Silver containing ore can be converted into silver in cyanide process. If true enter 1 , else enter 0 |
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| 296 | Question 30. What is the role of adsorption in froth floatation process used especially for concentration of sulphide ores? nina oil on sulnhide ore particles. |
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| 297 | Which method do you suggest for extraction of high reactivity metals? Why? |
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| 298 | Which of the following process does not involve heating? A. Calcination B. Smelting c. Roasting D. Levigation |
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| 299 | How is ore of aluminium concentrated? A. Roasting B. Leaching C. Froth floatation D. Using Wilfley table |
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| 300 | A mixture of barium sulphate and ( mathrm{H}_{2} mathrm{O} ) can be separated by the method of |
12 |
| 301 | Question 17. Why copper matte is put in silica lined converter! | 12 |
| 302 | Assertion: When an electric current is passed through the copper sulphate electrolyte, the impure copper anode gradually dissolve and pure copper is deposited on the cathode. Reason: Pure metals are deposited in electroplating techniques. A. Both Assertion and Reason are true and Reason is the correct explanation of Assertion B. Both Assertion and Reason are true but Reason is not the correct explanation of Assertion c. Assertion is true but Reason is false D. Assertion is false but Reason is true E. Both Assertion and Reason are false |
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| 303 | Which occurs to minimum extent in nature? ( mathbf{A} cdot H g S ) в. ( H_{2} ). ( mathrm{c} cdot B i_{2} S_{3} ) ( mathrm{D} cdot mathrm{CS}_{2} ) |
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| 304 | Cryolite is : A. Sodium aluminium fluoride B. Magnesium silicate C. Calcium Magnesium Carbonate D. Sodium borofluoride |
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| 305 | What are ellingham diagrams? Write any two features of it. |
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| 306 | The methods for extracting metals from their ores are: 1. roasting a metal sulphide 2. chemical reduction of a metal oxide 3. electrolysis, The preferred method depends on ( boldsymbol{E}^{circ} ) value for the reducing half-reaction: ( M^{n+}(a q)+n e^{-} rightarrow M(s) ) Which method is preferred for the metals with the most positive ( boldsymbol{E}^{circ} ) values? |
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| 307 | Identify the term/substance in each of the following: (i) The tendency of an atom to attract electrons to itself when combined in a compound. (ii) The method used to separate ore from gangue by preferential wetting. (iii) The catalyst used in the conversion of ethyne to ethane (iv) The type of reactions alkenes undergo. (v) The electrons present in the outermost shell of an atom. |
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| 308 | Auto reduction process is used for the extraction of: This question has multiple correct options A. cu в. ( mathrm{Hg} ) ( c cdot P b ) D. Al |
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| 309 | In the Castner’s process of extraction of sodium, the cathode is: A. iron rod B. nickel rod c. copper rod D. graphite rod |
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| 310 | Si of high purity to be used in semiconductor can be prepared by following methods: ( . S i O_{2}+2 C rightarrow S i+2 C O ) ॥. ( S i+2 C l_{2} rightarrow S i C l_{4} ) ( S i C l_{4}+2 M g rightarrow S i+2 M g C l_{2} ) Better method is : ( A ) B. ॥ c. both (A) and (B) D. None of these |
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| 311 | In the electrolytic reduction of alumina, the electrolyte is covered with coke powder because, it A. prevents oxidation of aluminium formed B. reacts with aluminium forming aluminium carbide C. prevents heat loss from the electrolyte D. none of the above |
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| 312 | The non-metallic element present in the mineral cryolite is: A. ( F ) в. ( C l ) ( c cdot B r ) D. ( I ) |
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| 313 | Metal oxides are reduced to metal by: A. electrolytic reduction B. liquation c. distillation D. none of the above |
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| 314 | Formula of ruby copper is : ( mathbf{A} cdot C u_{2} O ) в. ( C u_{2} S ) c. ( C u C O_{3} cdot C u(O H)_{2} ) D. ( C u F e S_{2} ) |
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| 315 | Which of the following alloys contain Cu and Zn? A. Bronze B. Brass c. Gun metal D. stee |
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| 316 | Zn-Ag alloy formed in the upper layer of molten lead is skimmed off from the surface of the molten lead by perforated ladles. This alloy contains leed as impurity, This impurity of Pb is removed by : A. distillation process B. cupellation c. liquation D. Bett’s electrolysis |
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| 317 | The least electropositive metal among the following is : A . Au в. Мв ( c cdot A ) D. zn |
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| 318 | Select the correct statements for Ellingham diagram. This question has multiple correct options |
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| 319 | Which of the following statement is incorrect about the extraction of lead from galena? A. Galena is a sulphide ore and therefore, it is concentrated by froth flotation process B. Self reduction takes place in absence of air. C. Complete roasting of galena gives PbO which is then reduced by coke or ( mathrm{CO} ) to give metallic lead. D. ( F e S i O_{3} ) is obtained as slag. |
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| 320 | Which of the following statements is/are correct? a) In the decomposition of an oxide into oxygen and metal vapour, entropy increases. b) Decomposition of an oxide is an endothermic change. c) To make ( Delta G^{0} ) negative, temperature should be high enough so that ( T Delta S^{0}> ) ( Delta boldsymbol{H}^{0} ) A. (a), (b) only are correct B. (b), (c) only are correct C. (a), (c) only are correct D. ( (a),(b),(c) ) are correct |
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| 321 | The process described above in the passage is regarding: A. Ore dressing B. Pyrometallurgical extraction c. Hydrometallurgical extraction D. Purification of metal. |
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| 322 | Column chromatography involves separation of a mixture over a column of adsorbent (stationary phase) packed in a glass tube. Depending upon the degree of adsorption complete separation takes place. In the given column, three coloured bands ( x, y, z ) are formed. Identify the correct statement A. ( x, y ) and ( z ) are adsorbed to the same extent B. The most readily adsorbed component is retained nea the top (x) c. The most readily absorbed component comes ( operatorname{down}(z) ) D. ( x, y, z ) layers are formed according to the wavelengths of the colours not on the basis of adsorption |
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| 323 | ( boldsymbol{C} boldsymbol{u}_{2} boldsymbol{S}+mathbf{2} boldsymbol{C} boldsymbol{u}_{2} boldsymbol{O} rightarrow boldsymbol{6} boldsymbol{C} boldsymbol{u}+boldsymbol{S} boldsymbol{O}_{2} ) In which process of metallurgy of copper, above equation is involved – A. roasting B. self reduction c. refining D. purification |
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| 324 | metals occur free in nature A . Alkal B. Noble c. Iron D. Aluminum |
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| 325 | The reducing agent in thermite process is: A . ( A l ) в. ( M g ) c. ( F e ) D. ( S ) i |
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| 326 | Assertion Zinc but not copper is used for the recovery of silver from the complex ( left[boldsymbol{A} boldsymbol{g}(boldsymbol{C} boldsymbol{N})_{2}right] ) Reason Zinc is cheaper as well as a strong reducing agent than Cu and replaces Ag from the complex. Read the above assertion and reason and choose the correct option regarding ¡t. 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 |
| 327 | WO 0.26 In the extraction of chlorine from brine ………… (a) AGⓇ for the overall reaction is negative. (b) AGⓇ for the overall reaction is positive. (c) E for the overall reaction has negative value. (d) EⓇ for the overall reaction has positive value. |
12 |
| 328 | Considering Ellingham diagram, which of the following metals can be used to reduced alumina? ( mathbf{A} cdot M g ) в. ( F e ) c. ( C u ) D. ( Z n ) |
12 |
| 329 | Explain zone refining. | 12 |
| 330 | Draw the diagram showing froth floatation method and label its parts | 12 |
| 331 | During the process of electrolyte refining of copper, some metals present as impurity settle as ‘anode mud’. These are: A. Sn and Ag B. Pb and Zn c. ( A g ) and ( A u ) D. Fe and Ni |
12 |
| 332 | Formation of ( N i(C O)_{4} ) and its subsequent decomposition into Ni and CO (recycled) makes basis of Mond’s process. ( N i+4 C O stackrel{T_{1}}{longrightarrow} N i(C O)_{4} stackrel{T_{2}}{longrightarrow} N i+ ) ( 4 C O ) ( T_{1} ) and ( T_{2} ) are: A ( cdot 100^{circ} mathrm{C}, 50^{circ} mathrm{C} ) в. ( 50^{circ} mathrm{C}, 100^{circ} mathrm{C} ) c. ( 50^{circ} mathrm{C}, 230^{circ} mathrm{C} ) D. ( 230^{circ} mathrm{C}, 50^{circ} mathrm{C} ) |
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| 333 | Mond process is used in the extraction of |
12 |
| 334 | The mass of carbon anode consumed (giving the only carbon dioxide) in the production of ( 270 mathrm{kg} ) of aluminium metal from bauxite by the Hall process is: [Atomic mass : ( A l=27] ) A. ( 90 mathrm{kg} ) в. ( 540 mathrm{kg} ) c. ( 180 mathrm{kg} ) D. 270 ( k g ) |
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| 335 | Match the column ( begin{array}{lll}text { A) Cryalite } & text { P) } mathrm{CazB}_{6} mathrm{O}_{12} mathrm{SH}_{2} mathrm{O} \ text { B) Calemanite } & mathrm{Q}) mathrm{Al}_{2} mathrm{O}_{3} 2 mathrm{H}_{2} mathrm{O} \ text { C) Bauxite } & mathrm{R}) mathrm{Na}_{3} mathrm{AlF}_{6} \ text { D)Sidente } & mathrm{S}) mathrm{FeCO}_{3} \ & text { T) } mathrm{Na}_{2} mathrm{B}_{4} mathrm{O}_{7} 1 mathrm{OH}_{2} mathrm{O}end{array} ) |
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| 336 | The method of zone refining of metals is based on the principle of: A. greater noble character of the solid metal than that of the impurity B. greater solubility of the impurity in the molten state than in the solid C . greater mobility of the pure metal than that of impurity D. higher melting point of the impurity than that of the pure metal |
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| 337 | Silver is purified by the distillation process. A . True B. False |
12 |
| 338 | The following reactions take place in the blast furnace in the preparation of impure iron. Identify the reaction pertaining to the formation of the slag. A ( cdot F e_{2} O_{3}(s)+3 C O(g) rightarrow 2 F e(l)+3 C O_{2}(g) ) B . ( operatorname{CaCO}_{3}(s) rightarrow operatorname{CaO}(s)+operatorname{CO}_{2}(g) ) ( mathbf{c} cdot operatorname{CaO}(s)+operatorname{Si} O_{2}(s) rightarrow operatorname{CaSiO}_{3}(s) ) D ( cdot 2 C(s)+O_{2}(g) longrightarrow 2 C O(g) ) |
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| 339 | Which element is present in Ruby as impurity? A. ( C u ) в. ( C r ) c. ( A u ) D. ( Z n ) |
12 |
| 340 | Composition of azurite mineral is: A ( cdot C u C O_{3} cdot C u O ) в. ( C uleft(H C O_{3}right)_{2} . C u(O H)_{2} ) ( mathrm{c} cdot 2 mathrm{Cu} mathrm{CO}_{3} cdot mathrm{Cu}(mathrm{OH})_{2} ) D. None of these |
12 |
| 341 | Give both chemical equation of ‘Mond process’ used in nickel refining: | 12 |
| 342 | ( boldsymbol{C} boldsymbol{a}_{boldsymbol{4}}left(boldsymbol{P} boldsymbol{O}_{boldsymbol{4}}right)_{2} boldsymbol{O} ) is: This question has multiple correct options A. thomas slag B. formed in manufacturing of steel iron C. used in manufacture of phosphorus fertilizer D. used as a refractory material |
12 |
| 343 | ( boldsymbol{A} boldsymbol{g}_{2} boldsymbol{S}+boldsymbol{N} boldsymbol{a} boldsymbol{N} longrightarrow boldsymbol{A} ) ( boldsymbol{A}+boldsymbol{Z} boldsymbol{n} longrightarrow boldsymbol{B} ) ( B ) is a metal. Hence ( A ) and ( B ) is: A ( cdot operatorname{Na}_{2}left[operatorname{Zn}(C N)_{4}right], Z n ) в. ( operatorname{Na}left[operatorname{Ag}(C N)_{2}right], ) А ( g ) c. ( operatorname{Na}left[A g(C N)_{4}right], A g ) D. ( operatorname{Na}_{3}left[operatorname{Ag}(C N)_{4}right], A g ) |
12 |
| 344 | The smelting of iron in a blast furnace involves the following processes: This question has multiple correct options A. combustion B. reduction c. slag foramtoin D. sublimation |
12 |
| 345 | Assertion Froth floatation process is based on the different wetting nature of ore and gangue particles. Reason Mustard oil is used as brother in froth floation process. 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 |
| 346 | Hydraulic separation method is used for the concentration of which ore? This question has multiple correct options A . Cassiterite B. Haematite c. Calamine D. Galena |
12 |
| 347 | Zone refining is a method to obtain: This question has multiple correct options A. ultra pure boron B. ultra pure lead c. ultra pure silicon D. all |
12 |
| 348 | Match the column. | 12 |
| 349 | Ores in the form of sulphide and carbonate are converted into: A. water B. oxides c. aldehyde D. alcohol |
12 |
| 350 | The mass of carbon anode consumed (giving of carbon dioxide) in the production of ( 270 mathrm{kg} ) aluminium metal bum bauxite by Hall process is: (Atomic ( operatorname{mass} A l=27) ) A. ( 180 mathrm{kg} ) в. ( 270 mathrm{kg} ) c. ( 540 mathrm{kg} ) D. ( 90 mathrm{kg} ) |
12 |
| 351 | Zinc can displace silver from ( left[boldsymbol{A} boldsymbol{g}(boldsymbol{C} boldsymbol{N})_{2}right]^{-} ) If true enter 1 , else enter 0 . |
12 |
| 352 | A copper coin was electroplated with Zn and then heated at high temperature until there is a change in colour. What will be the resulting colour? A. White B. Black c. Silver D. Golden |
12 |
| 353 | Silver is found in nature both in native and combined state. A. True B. False |
12 |
| 354 | Which one of the following statements İs incorrect? A. In the aluminothermite process, aluminium acts as reducing agent B. Lead is extracted from its chief ore by both carbon reduction and self-reduction. C. Zinc is extracted from its chief ore by carbon reduction. D. Extraction of gold involves the leaching of ore with cyanide solution followed by reduction with zinc. E. In Hall-Heroult process, the electrolyte used is a molten mixture of alumina, sodium hydroxide and cryolite. |
12 |
| 355 | In the extraction of silver by Mac-Arther cyanide process, a small amount of ( K N O_{3} ) is also added as flux. The function of ( boldsymbol{K} boldsymbol{N} boldsymbol{O}_{3} ) is: A ( cdot ) to oxidise ( A g ) in the native from to ( A g^{-} ) B. to oxidise lead and zinc impurities c. to form a complex with ( A g^{+} ) which is then reduced to metallic silver by using zinç D. to oxidise the sulphur in the argentite ore to ( S O_{2} ) which escapes from the reaction |
12 |
| 356 | Which one is a mineral of zinc? A. Galena B. Calamine c. Cerussite D. cinnabar |
12 |
| 357 | The function of adding cryolite in the electrolyte reduction of alumina by HallHeroult process is to: This question has multiple correct options A. dissolve alumina B. lower melting point of alumina c. lower the fuel bill D. increase the electrical conductivity of alumina |
12 |
| 358 | The percentage of lanthanides and iron, respectively, in Misch metal are: ( mathbf{A} cdot 50,50 ) B. 75,25 c. 90,10 D. 95,5 |
12 |
| 359 | Zone refining is a method to obtain: A. very high temperature B. ultra pure ( A l ) c. ultra pure metals D. ultra pure oxides |
12 |
| 360 | Write chemical equation to represent the most probable outcome in the following reaction and choose the correct option. [ boldsymbol{C d C O}_{3} stackrel{boldsymbol{Delta}}{rightarrow} ] A ( cdot mathrm{CdCO}_{3} stackrel{Delta}{longrightarrow} mathrm{Cd} mathrm{O}+mathrm{CO}_{2} ) в. ( 2 mathrm{CdCO}_{3} ) 오 ( 2 mathrm{CdO}+2 mathrm{CO}+mathrm{O}_{2} ) c. No reaction D. None of these |
12 |
| 361 | The process of concentrating Au and Ag ores is based upon their solubility in : A . ( N H_{3} ) в. ( H N O_{3} ) c. ( H C l ) D. ( K C N ) |
12 |
| 362 | The oil used in the froth floatation method for the purification of ore is A. coconut oil B. olive oil c. Pine oil D. castor oil |
12 |
| 363 | Which of the following process is for purification of metals? A. Froath floatation B. Leaching c. Liquidation D. washing |
12 |
| 364 | Which of the following sulphides when heated strongly in air gives the corresponding metal without undergoing separate reduction of oxide? A ( cdot C u_{2} S ) в. FeS с. Нg S D. ( Z n S ) |
12 |
| 365 | Copper, which is extracted from cuprite, is a/an: A. sulphide ore B. carbonate ore c. oxide ore D. halide ore |
12 |
| 366 | Which one of the following ores is best concentrated by froth-floatation method? A . Magnetite B. Cassiterite c. Galena D. Malachite |
12 |
| 367 | Iron is not found naturally in the form of the free metal. Gold can be found naturally as the free metal. Explain. | 12 |
| 368 | During the electrolysis of carnallite, ( M g C l_{2} ) is decomposed and not ( K C l ) This is because of : A . lower decomposition voltage of ( M g C l_{2} ) than that of ( K C l ) B. reverse reaction ( M g C l_{2}+2 K rightarrow M g+2 K C l ), if ( K C l ) i decomposed under other experimental condition c. both ( A ) and ( B ) D. none of the above |
12 |
| 369 | The ratio of ( F e_{2} O_{3} ) and ( A l ) by weight, in thermite is about: A . 1: 3 B. 1: 2 c. 3: 1 D. none of the above |
12 |
| 370 | In cyamide extraction process of silver from argentite ore, the oxidising and reducing agents are respectively. ( A cdot O_{2} ) and ( C O_{2} ) B. ( O_{2} ) and ( Z n ) dust ( mathrm{c} . H N O_{3} ) and ( Z n ) dust D. ( H N O_{3} ) and ( C O ) |
12 |
| 371 | A cuprous ore among the following is A . cuprite B. malachite c. chalcopyrites D. azurite |
12 |
| 372 | Explain in detail the processes involved in the production of pig iron and steel. | 12 |
| 373 | Ellingham diagram in the extraction of zinc. |
12 |
| 374 | Tincal mainly contains: A. ( N a N O_{3} ) в. ( N a_{2} B_{4} O_{7} .10 H_{2} O ) ( mathbf{c} cdot N a_{2} C O_{3} ) D. ( N a_{2} S O_{4} ) |
12 |
| 375 | Gangue have: ( A ). sand and soil B. silt C . gravel D. all of these |
12 |
| 376 | Which of the following ore is best concentrated by froth flotation method? This question has multiple correct options A. Galena B. Cassiterite c. Magnetite D. zinc blende |
12 |
| 377 | Sulphide ore of copper can be concentrated by froth floatation process. A. True B. False |
12 |
| 378 | Which one of the following statements is not correct? A. Nickel forms ( N i(C O)_{4} ) B. All the transition metals form monometallic carbonyl c. ( N i(C O)_{4} ) is volatile and decomposes into Ni and ( c o ) D. Transition metals form complexes |
12 |
| 379 | Select the correct statement(s): This question has multiple correct options A. When temperature is reised, a point will be reached where the graph crosses the ( Delta G=0 ) line. Below this temperature, the free energy of formatin of the oxide is negative, so the oxide is stable B. When temperature is raised, a point will be reached where the graph crosses the ( Delta G=0 ) line. Above this temperature, the free energy of formation of the oxide is positive, and the oxide becomes unstable, and should decompose into the metal and dioxygen. C. Theoretically, all oxides can be decomposed to give the metal and dioxygen if.a sufficiently high temperature can be attained. D. Theoretically, all oxides cannot be decomposed to give the metal and dioxygen if a sufficiently high temperature can he attaincd |
12 |
| 380 | Silk moth feed on: A. eucalyptus leaf B. grapes Leaves c. mulberry Leaves D. neem leaves |
12 |
| 381 | 24. Assertion : Leaching is a process of reduction Reason: Leaching involves treatment of the ore with a suitable reagent so as to make it soluble while impurities remains insoluble. |
12 |
| 382 | Na ( C N ) is sometimes added in the froth floatation process as a depressant when ( Z n S ) and ( P b S ) minerals are expected because: A ( cdot Z n S ) forms soluble complex ( N a_{2}left[Z n(C N)_{4}right] ) while ( P b S ) form froth B . ( P b(C N)_{2} ) is precipitated while no effect on ( Z n S ) form froth C . ( P b S ) forms soluble complex ( N a_{2}left[Z n(P b)_{4}right] ) while ( Z n S ) form froth D. ( N a C N ) is never added in froth floatation process |
12 |
| 383 | Which of the following method is used for extracting metals from ores? A. Reduction B. Melting c. Electrolysis D. Both ( A ) and ( C ) |
12 |
| 384 | The process used in purifying metals by electrolysis is called: A. electroplating B. electrometallurgy c. electrorefining D. electrodeposition |
12 |
| 385 | In the extraction of aluminium by electrolytic process, cryolite is added to A. lower the melting point of alumina B. increase the electrical conductivity c. minimise the anode effect D. remove impurities from alumina |
12 |
| 386 | Froth floatation process for the concentration of ores is an illustration of physical phenomenon of A. adsorption B. absorption c. conagulation D. sedimentation |
12 |
| 387 | Which of the following metals is obtained by the reduction of metal oxide using hydrogen gas? A. ( C u ) в. ( A l ) c. ( M g ) D. ( F e ) |
12 |
| 388 | What is meant by the term chromatography? |
12 |
| 389 | The following reactions take place in the blast furnace in the preparation of impure iron.Identify the reaction pertaining to the formation of the slag. A ( cdot 2 C(s)+O_{2}(g) rightarrow 2 C O(g) ) B. ( F e_{2} O_{3}(s)+3 C O(g) rightarrow 2 F e(ell)+3 C O_{2}(g) ) c. ( C a C O_{3}(s) rightarrow C a O(s)+C O_{2}(g) ) D. ( operatorname{CaO}(s)+operatorname{Si} O_{2}(s) rightarrow operatorname{CaSiO}_{3}(s) ) |
12 |
| 390 | Which of the following statements is/are correct? This question has multiple correct options A. Extractive metallurgy of iron involves reduction by carbon monoxide and carbon. B. Extraction of zinc from ore sphalerite involves the roasting and carbon reduction. C. Tin contain magnetic impurity of ( mathrm{Fe} mathrm{Cr} mathrm{O}_{4} ) D. Cuprite and argentite are oxide ores. E. Bauxite is concentrated by leaching process. F. Electrometallurgy is preferred method for extraction of highly reactive metals. |
12 |
| 391 | The MacArthur-Forrest process is used for the extraction of: A. ( C u ) в. ( A g ) c. ( F e ) D. ( Z n ) |
12 |
| 392 | ( mathbf{2} boldsymbol{A} boldsymbol{l}left(boldsymbol{N} boldsymbol{O}_{3}right)_{3} stackrel{boldsymbol{Delta}}{rightarrow} boldsymbol{A} boldsymbol{l}_{2} boldsymbol{O}_{3}+boldsymbol{6} boldsymbol{N} boldsymbol{O}_{3}+ ) ( mathbf{1 . 5 0}_{mathbf{2}} ) If reaction is correct enter 1 else 0 |
12 |
| 393 | For the reduction of FeO at the temperature corresponding to point ( mathrm{D} ) which of the following statement is correct? ( mathbf{A} cdot triangle G^{0} ) value for the overall reduction with carbon monoxide is zero B. ( triangle G^{0} ) value for the overall reaction with a mixture of mol carbon and 1 mol oxygen is positive. C ( . triangle G^{0} ) value for the overall reduction with a mixture of 2 mol carbon and 1 mol oxygen will be positive. D. ( triangle G^{0} ) value for the reduction reaction with carbon monoxide is negative |
12 |
| 394 | A metal ‘X’ is prepared by the electrolysis of fused chloride. It reacts with hydrogen to form a colourless solid, from which hydrogen gas is released on treatment with water. The metal’X’ is : ( A cdot A ) в. са ( c cdot c u ) D. zn |
12 |
| 395 | Q. 54 Assertion (A) Hydrometallurgy involves dissol reagent followed by precipitation by a more electropo Reason (R) Copper is extracted by hydrometallurgy. metallurgy involves dissolving the ore in a suitable ecipitation by a more electropositive metal. |
12 |
| 396 | Gold is also extracted by cyanide process as in case of silver. Write the reactions. ( mathbf{A} cdot 2left[A u(C N)_{2}right]^{-}+Z n rightarrowleft[Z n(C N)_{4}right]^{2-}+2 A u downarrow ) ( mathbf{B} cdot 4left[A u(C N)_{2}right]^{-}+Z n rightarrowleft[Z n(C N)_{4}right]^{2-}+4 A u downarrow ) ( mathbf{c} cdotleft[A u(C N)_{2}right]^{-}+Z n rightarrowleft[Z n(C N)_{4}right]^{2-}+A u downarrow ) D. None of these |
12 |
| 397 | NaCN used in the froth flotation method for the purification of ore is:- A. ( Z n S ) which contain ( P b S ) B. ( C u_{2} S ) which contain ( F e_{e} S_{3} ) c. ( P b S ) which contain ( Z n S ) D. ( P b S ) which contain ( S i O_{2} ) |
12 |
| 398 | What is concentration of ore? A. Increasing the concentration of metal B. Reducing the concentration of metal C. Reducing hydrogen ions D. Both ( A ) and ( C ) |
12 |
| 399 | The ore that is concentrated by froth floatation process is A. cinnabar B. bauxite c. malachite D. zineite |
12 |
| 400 | 5. Heating of concentrated ore in absence of air for conversion into oxide ore is known as (a) roasting (b) calcination (c) reduction (d) none of these |
12 |
| 401 | During the extraction of ( mathrm{Ag} ) and ( mathrm{Au} ) using a KCN solution,cyanide ions react with metal ions as: This question has multiple correct options A. a reducing agent B. a complexing agent c. a oxidizing agent D. a Lewis base |
12 |
| 402 | Which process of purification is represented by the following scheme? ( underset{i m p u r e}{boldsymbol{T} boldsymbol{i}}+boldsymbol{2} boldsymbol{I}_{2} stackrel{250^{circ} C}{longrightarrow} boldsymbol{T} boldsymbol{i} boldsymbol{I}_{4} frac{1400^{circ} boldsymbol{C}}{longrightarrow} boldsymbol{T} boldsymbol{i}+ ) ( 2 I_{2} ) A. Cupellation B. zone refiningg c. van-Arkel process D. Poling |
12 |
| 403 | The major step involved in extraction of a metal after its ore is : A. concentration B. reduction c. purification D. all of these |
12 |
| 404 | What is the formula of calamine? | 12 |
| 405 | The divalent metal whose oxide is reduced to metal by electrolysis of its fused salt is ( (A l / N a / M g / K) ) |
12 |
| 406 | Explain how silver is extracted from its chief ore. |
12 |
| 407 | To make the following reduction process spontaneous, temperature should be: ( Z n O+C longrightarrow Z n+C O ) A ( cdot 1000^{circ} mathrm{C} ) В. ( >1000^{circ} mathrm{C} ) ( c cdot<500^{circ} C ) D. ( <1000^{circ} mathrm{C} ) |
12 |
| 408 | Froth flotation is a process of A . oxidation B. reduction C. refining D. concentration |
12 |
| 409 | 0. 14 At the temperature corresponding to which of the points in Fig. Feo will be reduced to Fe by coupling the reaction 2FeO — 2Fe+ 0, with all of the following reactions? bal 1. C+ 0 COzawo d notab sisusta 2. 2C + 02 – 200 3.200+ 02 – 2002 2 (a) Point A (b) Point B (c) Point D (d) Point E |
12 |
| 410 | The final step for the extraction of copper pyrites in Bessemer converter involves the reaction A ( cdot C u_{2} S+2 F e O rightarrow 2 C u+2 F e+S O_{2} ) в. ( C u_{2} S+2 C u_{2} O rightarrow 6 C u+S O_{2} ) c. ( 4 C u_{2} O+F e S rightarrow 8 C u+2 F e S O_{4} ) D. ( 2 C u_{2} O+F e S rightarrow 4 C u+F e+S O_{2} ) |
12 |
| 411 | The composition of malachite is: A. ( C u F e S_{2} ) в. ( C u C O_{3} ) c. ( C u C O_{3} cdot C u(O H)_{2} ) D. ( C u(O H)_{2} ) |
12 |
| 412 | Which of the following statements is correct? (i) Copper is extracted by hydrometallurgy from low-grade ores. (ii) In the electrolytic reduction of alumina, graphite is acting as an anode and steel vessel with the lining of carbon acts as an anode. (iii) In Hall-Heroult process, aluminium is obtained at anode and ( mathrm{CO} ) and ( boldsymbol{C O}_{2} ) are produced at the cathode. A. (i) only B. (i) and (ii) only C . (ii) and (iii) only D. All of these |
12 |
| 413 | Out of ( C ) and ( C O, ) which is a better reducing agent at ( 673 K ? ) |
12 |
| 414 | Q. 11 Choose the correct option of temperature at which carbon reduces Feo to iron and produces CO. (a) Below temperature at point A (b) Approximately at the temperature corresponding to point A (C) Above temperature at point A but below temperature at point D (d) Above temperature at point A |
12 |
| 415 | The process employed for the purification of copper with cuprous oxide as the impurity is: A . poling B. liquation c. electrolytic process D. oxidation |
12 |
| 416 | Sketch shown is of an electrolytic cell used in the extraction of aluminium: What is the substance of which the electrode A is made? A. Graphite B. Diamond ( c . ) Iron D. Aluminium |
12 |
| 417 | Process of removal of gangue from the ore are based on: A. differences between physical and chemical properties of the gangue and the ore B. difference between densities of gangue and ore C. difference between melting point between of gangue and ore D. all of the above |
12 |
| 418 | Bessemerization is carried out for: I. Fe II. Cu III. ( A ) IV. ( A g ) A . ।, ॥ в. ॥, III c. ॥ा, । v D. I, III |
12 |
| 419 | What is electrometallurgy? | 12 |
| 420 | Number of electrons involved in the electrodeposition of ( 63.5 g ) of ( C u ) from a solution of ( C u S O_{4} ) is? A ( cdot 6.022 times 10^{23} ) 3 ( 3.02 times 10^{2}+0.62^{23} ) B. ( 3.011 times 10^{23} ) c. ( 12.044 times 10^{23} ) D. ( 6.022 times 10^{22} ) |
12 |
| 421 | Heating the ore is in the presence of air is ? A. roasting B. melting c. calcination D. none of these |
12 |
| 422 | What is the purpose of using coke? A. Reducing agent B. Oxidising agent c. both A and B D. none of the above |
12 |
| 423 | Which of the following metallurgical processes does not involve heating? A. Smelting B. Calcination c. Roasting D. Leaching |
12 |
| 424 | Four metals and their methods of refinement are given : (i) ( N i, C u, Z r, G a ) (ii) Electrolysis, van Arkel process, Zone refining, Monds process Choose the right method for each metal. |
12 |
| 425 | 41. The important metal used with iron to produce stainless steel is (1) Aluminium (2) Chromium (3) Tin (4) Carbon (4) Carh |
12 |
| 426 | Froth flotation process used for the concentration of sulfide ore ( mathbf{A} cdot ) is based on the difference in wettability of different minerals B. uses sodium ethly xanthate, ( C_{2} H_{5} O C S_{2} N a ) as collector C. uses ( N a C N ) as depressant in the mixture of ZnS and PbS when ZnS forms soluble complex and Pbs forms froth D. all of the above statements are correct |
12 |
| 427 | Sulphide ore is concentrated by the method: 1. Froth flotation process 2. Magnetic separation 3. Gravity method 4. Calcination method |
12 |
| 428 | The centre of the earth is a core, mainly containing: A. silicon that forms clay B. copper that gives radiation c. iron that creates a magnetic field D. magnesium that colours volcanic flames |
12 |
| 429 | Which of the following sulphides can not be reduced to metal by ( H_{2} ) at about ( mathbf{1 0 0 0}^{circ} mathbf{C} ? ) A. Нg S в. ( P b S ) с. ( B i_{2}, S_{3} ) D. All of these |
12 |
| 430 | The electrolysis of pure alumina is not feasible because: A. it is bad conductor of electricity and its fusion temperature is highh B. it is volatile in nature c. it is decomposed when fused D. it is amphoteric |
12 |
| 431 | Zone refining process is used for the: A. Concentration of an ore B. Reduction of a metal oxide C. Purification of metal D. Purification of an ore |
12 |
| 432 | Formation of ( N i(C O)_{4} ) and subsequently its decomposition into Ni and ( mathrm{CO} ) (recycled) make the basis of Mond’s process: ( mathbf{N i}+ ) ( mathbf{4} boldsymbol{C O} quad boldsymbol{T}_{1} quad boldsymbol{N i}(boldsymbol{C O})_{4} quad underline{boldsymbol{T}}_{2} quad boldsymbol{N} boldsymbol{i}+ ) ( 4 C O ) ( T_{1} ) and ( T_{2} ) are : A ( cdot 100^{circ} mathrm{C}, 50^{circ} mathrm{C} ) B . ( 50^{circ} mathrm{C}, 100^{circ} mathrm{C} ) c. ( 50^{circ} mathrm{C}, 230^{circ} mathrm{C} ) D ( cdot 230^{circ} mathrm{C}, 50^{circ} mathrm{C} ) |
12 |
| 433 | Write the role of Dilute ( N a C N ) in the extraction of Gold |
12 |
| 434 | Molten iron from the blast furnace contains impurities. The process of turning the impure iron into steel involves blowing oxygen into the molten iron and adding calcium oxide. What are the reasons for blowing in oxygen and adding calcium oxide? A. Carbon is removed by reaction with oxygen, reacts with acidic impurities making slag B. Carbon is removed by reacting with oxygen, reacts with slag and so removes it C. Iron reacts with the oxygen, reacts with acidic impurities making slag D. Iron reacts with the oxygen, reacts with slag and so removes it |
12 |
| 435 | Select the correct reduction process: This question has multiple correct options ( mathbf{A} cdot 2left[A g(C N)_{2}right]^{-}+Z n longrightarrowleft[Z n(C N)_{4}right]^{2-}+2 A g ) ( mathbf{B} cdot C u O+H_{2} longrightarrow C u+H_{2} O ) ( mathbf{c} cdot A l_{2} O_{3}+3 Z n longrightarrow 2 A l+3 Z n O ) D. ( M g O+C frac{text {high}}{text {temp}} M g+C O ) |
12 |
| 436 | Sometimes it is possible to separate two sulphide ores by adjusting the proportion of oil to water by using depressants. When a depressant NaCN is added to an ore containing ( Z n S ) and ( P b S, ) what is the correct observation? A. ( N a C N ) prevents ( P b S ) from coming to the froth but allows ( Z n S ) to come with froth B. ( N a C N ) prevents ( Z n S ) from coming to the froth but allows ( P b S ) to come with froth C. ( N a C N ) prevents frothing of both ( Z n S ) and ( P b S ), hence no froth is formed D. ( N a C N ) does not act as depressant hence a mixture of ( P b S ) and ( Z n S ) is found in the froth |
12 |
| 437 | Select the correct statement for electrolysis of ( A l_{2} O_{3} ) by Hall-Heroult process. A . Cryolite ( N a_{3}left[A l F_{6}right] ) lowers the melting point of ( A l_{2} O_{3} ) and increases its electrical conductivity. B. Al is obtained at cathode and probably ( C O_{2} ) at anode. C. Both of the above statements are correct. D. None of the above statements are correct. |
12 |
| 438 | Monds process is used for: A . ( N i ) в. ( A l ) c. ( F e ) D. ( C u ) |
12 |
| 439 | Which phenomenon occurs during the following change? Solid wax left out in the sun. A. Sublimation B. Melting c. condensation D. Evaporation |
12 |
| 440 | Aluminium is extracted by: A. Heating sodium aluminium silicate to a high temperature B. Treating cryolite with sodium hydroxide solution under pressure C. Heating aluminium oxide with coke in a furnace D. The electrolysis of molten aluminium oxide in fused cryolite |
12 |
| 441 | Which of the following compound is used as froth stabliser? A. Fatty acid B. Aniline c. xanthates D. Phosphoric acid |
12 |
| 442 | Which of the following are main requirements for vapour phase refining? (i) Metal should form a volatile compound with the reagent. (ii) The volatile compound should be easily decomposable to give back pure metal. (iiii) Metal should be very reactive and form a stable compound with the reagent. A. (i), (ii) and (iii) B. (i) and (ii) c. (ii) and (iii) D. (i) and (iii) |
12 |
| 443 | Which of the following ores can be concentrated by froth floatation method and why? ( boldsymbol{F} boldsymbol{e}_{2} boldsymbol{O}_{3}, boldsymbol{Z} boldsymbol{n} boldsymbol{S}, boldsymbol{A} boldsymbol{I}_{2} boldsymbol{O}_{3} ) |
12 |
| 444 | In the metallurgy of sodium by electrolysis, excess of calcium chloride is mixed with sodium chloride to: A. make the latter a good conductor B. make the latter soft c. generate more energy for the electrolytic cell D. assist liquefaction of the latter at a much lower temperature |
12 |
| 445 | Which of the following match are correct: A. Goldschmidt aluminothermite process- ( C r_{2} O_{3} ) B. Mac Arther cyanide process-Fe C. Mond process -Ni D. Van Arkel process-Au |
12 |
| 446 | Which of the following metals occurs in nature principally oxide ores. A . ( C a ) в. ( C o ) ( c cdot C r ) D. ( C u ) |
12 |
| 447 | Which of the following metal is present in the anode mud during the electrolytic refining of copper? A. ( N a ) в. ( A l ) c. ( A u ) D. ( f e ) |
12 |
| 448 | ( N a C l ) and ( C a C l_{2} ) are also added to fused ( M g C l_{2} ) in the electrolysis of ( M g C l_{2} . ) Select the correct statement. This question has multiple correct options A. melting point is decreased and conductivity is increased B. melting point is increased and conductivity is decreased c. melting point and conductivity both are decreased D. melting point and conductivity both are increased |
12 |
| 449 | Which of the following metal oxides are reduced by CO? This question has multiple correct options A. zno B. ( F e_{2} O_{3} ) ( c . ) сао D. ( left.Aright|_{2} O_{3} ) |
12 |
| 450 | Although iron is only about two-third as abundant as aluminium in Earth’s crust but it costs only about onequarter as much as required to produce aluminium. If true enter 1 , else 0 |
12 |
| 451 | Assertion Reduction of a metal oxide is easier if the metal formed is in liquid state at the temperature of the reduction Reason The entropy is higher if the metal is in liquid state. 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 |
| 452 | Uranium with a mass number 237 and atomic number ( 92, ) changes to a nucleus with atomic number 90 and mass number 233 on emission of: A. ( beta ) -particle B. ( gamma ) -particle c. ( alpha ) -particle D. positron |
12 |
| 453 | Metals which have a low melting point are refined by liquation. A. True B. False |
12 |
| 454 | The formula of cassiterite is : ( mathbf{A} cdot P b S o_{4} ) B. ( S n O_{2} ) ( mathrm{c} cdot P b O_{2} ) D. None of these |
12 |
| 455 | For dissociation of limestone in the slag zone of the blast furnace. The reaction is: A. exothermic accompanied by increase in entropy B. endothermic accompanied by decrease in entropy C. endothermic accompanied by increase in entropy D. exothermic with no change in entropy |
12 |
| 456 | Gravity separation process is used for the concentration of A. calamine B. haematite c. chalcopyrites D. bauxite |
12 |
| 457 | Extraction of zinc from zinc blende is achieved by : A. electrolytic reduction B. roasting followed by reduction with carbon c. roasting followed by reduction with another metal D. roasting followed by self-reduction |
12 |
| 458 | Gold is extracted by hydrometallurgical process, based on its property: A. of being electropositive B. of being less reactive c. to form complex which are water soluble D. None of these |
12 |
| 459 | Describe the extraction of three different elements using carbon as the reducing agent. |
12 |
| 460 | Imagine a planet with an atmosphere that contains ( O_{2} ) and ( S O_{2} ) but no ( C O_{2} ) The chemical composition of the minerals you would expect to find the alkaline earth metals on such a planet is/ are: This question has multiple correct options A ( . M S O_{4} ) в. ( M_{2} S O_{3} ) c. ( M S O_{3} ) D. ( M_{2} S O_{4} ) |
12 |
| 461 | Q. 45 Match the items of Column I with items of Column II and assign the correct code. Column Column II A. Pendulum 1. Chrome steel Malachite 2 Nickel steel Calamine 3. Na₃AlF6 D. Cryolite 4. Cuco, Cu(OH), 5. Znco Codes A B C D A B C D (a) 1 2 3 4 (b) 2 4 5 3 (c) 2 3 4 5 (d) 4 5 3 2 |
12 |
| 462 | Which metal is refined by Van-Arkel method? A . ( N i ) в. ( A l ) ( c cdot s i ) D. ( T i ) |
12 |
| 463 | Which ore contains both iron and copper? A. Cuprite B. Chalcocite c. chalcopyrite D. Malachite |
12 |
| 464 | Which of the following process is used for concentration of ore? A. Froth flotation B. Electrolytic methods c. smelting D. Hoop’s process |
12 |
| 465 | Question 15. How is cast iron different from pig iron? ht |
12 |
| 466 | Which ore is concentrated by froth flotation method? A. Horn silver B. Bauxite c. cinnabar D. Haemattie |
12 |
| 467 | Which of the following is reactions is an example of autoreduction? A ( cdot F e_{3} O_{4}+4 C O rightarrow 3 F e+4 C O_{2} ) в. ( C u O+C rightarrow 2 C u+C O ) c. ( C u_{left(a_{a}right)}^{2+}+F e_{(s)} rightarrow C u_{(s)}+F e_{left(a_{9}right)+}^{(2)} ) D. ( C u_{2} O+frac{1}{2} C u_{2} S rightarrow 2 C u+frac{1}{2} S O_{2} ) |
12 |
| 468 | Assertion Tin is refined by liquation method. Reason Tin has low melting point as compared to impurities. 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 |
| 469 | ana Q. 9 Electrolytic refining is used to purify which of th thing is used to purify which of the following metals? (a) Cu and Zn (b) Ge and Si (c) Zr and Ti a n and Ans.(a) Conner and zipo oro hinhar gonerally nurified by using electroly |
12 |
| 470 | In the silver plating of copper, ( boldsymbol{K}left[boldsymbol{A} boldsymbol{g}(boldsymbol{C} boldsymbol{N})_{2}right] ) is used instead of ( A g N O_{3} . ) The reason is : ( A ). a thin layer of ( A g ) is formed on ( C u ) B. more voltage is required C. ( A g^{+} ) ions are completely removed from solution D. less availability of ( A g^{+} ) ions, as ( C u ) cannot displace ( A g ) from ( left[A g(C N)_{2}right]^{-} ) ion |
12 |
| 471 | In the electrolysis of alumina using cryolite, the reaction that takes place at cathode is: ( mathbf{A} cdot 4 H_{2} O+4 e^{-} rightarrow 2 H_{2}+4 O H^{-} ) B ( cdot 4 A l^{3+}+12 e^{-} rightarrow 4 A l ) c. ( 6 F_{2}+2 A l_{2} O_{3} rightarrow 4 A l F_{3}+3 O_{2} ) D. ( 12 F^{-} rightarrow 6 F_{2}+12 e^{-} ) |
12 |
| 472 | 0.87 Why are sulphide ores converted to oxide before reduction? | 12 |
| 473 | Which of the following is not a carbonate mineral? A. siderite B. Calamine c. limestone D. Fluorospar |
12 |
| 474 | Why is pine oil used in froth floatation method? |
12 |
| 475 | Na ( C l ) and ( C a C l_{2} ) are added to fused ( M g C l_{2} ) in the electrolysis of ( M g C l_{2} ) so that A. melting point is decreased and conductivity is increased B. melting point is increased and conductivity is decreased c. melting point and conductivity both are decreased D. melting point and conductivity both are increased |
12 |
| 476 | A metal that exists as a liquid at room temperature is obtained by heating its sulphide in the prescence of air. Identify the metal and its ore and the give the reaction involved? | 12 |
| 477 | Relate all the four columns of the table with and A in What is and ( begin{array}{llll}text { Metal } & text { Ore } & begin{array}{l}text { Chemical } \ text { formula }end{array} & begin{array}{l}text { Reducti } \ text { process }end{array} \ text { Al } & text { haemetite } & P b S & text { blast fur } \ text { Cu } & text { bauxite } & F e_{2} O_{3} & text { besseme } \ text { Fe } & begin{array}{l}text { copper } \ text { pyrite }end{array} & A l_{2} O_{3} .2 H_{2} O & text { froth flo } \ text { Pb } & text { galena } & C u F e S_{2} & text { Hall’s pro }end{array} ) |
12 |
| 478 | The chemical reactions involved in the extraction of metallic silver from argentite is – ( mathbf{2} N boldsymbol{a}left[boldsymbol{A} boldsymbol{g}(boldsymbol{C} boldsymbol{N})_{2}right]+boldsymbol{Z} boldsymbol{n} rightarrow ) ( boldsymbol{N} boldsymbol{a}_{2}left[boldsymbol{Z} boldsymbol{n}(boldsymbol{C} boldsymbol{N})_{4}right]+boldsymbol{2} boldsymbol{A} boldsymbol{g} downarrow ) If the statement is true enter 1 else 0 . |
12 |
| 479 | .17 Which of the following statements is correct about the role of substances added in the froth floatation process? (a) Collectors enhance the non-wettability of the mineral particles. To (b) Collectors enhance the wettability of gangue particles. (C) By using depressants in the process two sulphide ores can be separated. (d) Froth stabilisers decrease wettability of gangue. |
12 |
| 480 | Which one of the following ores is concentrated by froth floatation process? A . Magnesite B. Magnetic c. Galena D. Malachite |
12 |
| 481 | Which of the following process is not involved in manufacturing of steel? A. Bessemer process B. Open hearth process c. вор D. Thermite process |
12 |
| 482 | In which of the following isolations no reducing agent is required? A. Iron from haematite B. Aluminium from bauxite c. Mercury from cinnabar D. zinc from zinc blende |
12 |
| 483 | State True or False. Oxides of the s-block metals are strongly acidic and from salts with basic oxides. |
12 |
| 484 | A mineral is rich in ( mathrm{ZnS} ) and Pbs. If it can be concentrate by froth flotation process enter 1 else 0. |
12 |
| 485 | In which of the following isolations is no reducing agent required? A. Iron from haematire B. Tin from tin oxide c. Mercury from cinnabar D. zine from zinc blende |
12 |
| 486 | Out of ( C ) and ( C O, ) which is a better reducing agent for ( Z n O ? ) |
12 |
| 487 | The ( _{-}-_{-}-_{-}-_{-}- ) process is used in the extraction of copper and lead. |
12 |
| 488 | The most common ore of iron is A. calamine B. hematite c. zinc blende D. copper pyrite |
12 |
| 489 | Give the balanced equation for the conversion of argentite into metallic silver. |
12 |
| 490 | Match List-I with List-II. List – 1 a) Red lead p) Lead monoxide b) Litharge q) An ore of lead c) Galena r) An ore of tin d) Cassiterite s) Minium A ( cdot a-r ; b-s ; c-p ; d-q ) B. ( a-r ; b-q ; c-r ; d-p, q ) c. ( a-s ; b-p ; c-q ; d-r ) D. a-r; b-s; c-q; ;d-p |
12 |
| 491 | In simple distillation of liquids, it involves simultaneously. A. Vaporisation and condensation B. Heating and sublimation c. vaporisation and sublimation D. Boiling and filtration |
12 |
| 492 | Froth floatation: This question has multiple correct options A. is a physical method of separating mineral from the gangue B. is a method to concentrate the ore depending on the difference in wetability of gangue and the ore C. is used for the sulphide ores D. is a method in which impurities sink to the bottom |
12 |
| 493 | What happens when ( N a C N ) is added in ore containing ( P b S ) and ( Z n S ) during concentration by froth floatation method? |
12 |
| 494 | In froth floatation process, gangue particles are wetted by pine oil A. True B. False |
12 |
| 495 | Explain what is galvanization. What purpose is served by it? | 12 |
| 496 | Impurities found in ores are called: A. mud B. gangue c. electrolyte D. none of the above |
12 |
| 497 | What is the most common type of electrometallurgical processes to obtain pure metal? A. Electro-refining B. Electrowinning c. Both a and D. Oxidation |
12 |
| 498 | The cathode used in the electrolytic cell during aluminium extraction is made of A. aluminium B. carbon lining ( c . ) iron D. steel |
12 |
| 499 | Which one of the following ores is concentrated by chemical leaching method? A. Galena B. Copper pyritee c. cinnabur D. Argentite |
12 |
| 500 | Unwanted material with ore is called as A. Gangue B. Rust c. Slag D. Silica |
12 |
| 501 | The major role of fluorspar which is added in small amount in the electrolytic reduction of ( A l_{2} O_{3} ) dissolved in fused cryolite is : This question has multiple correct options A. as a catalyst B. to make the fused mixture very conducting c. to lower the temperature of melting D. to decreases the rate of oxidation of carbon at the anode |
12 |
| 502 | Litharge is a mineral of: A. Magnesium B. Lithium c. Lead D. zinc |
12 |
| 503 | ZnS and PbS are separated by using? | 12 |
| 504 | In the equation, ( 4 M+8 C N^{-}+2 H_{2} O+O_{2} longrightarrow ) ( mathbf{4}left[boldsymbol{M}(boldsymbol{C} boldsymbol{N})_{2}right]^{-}+mathbf{4} boldsymbol{O} boldsymbol{H}^{-} ) the metal M is: This question has multiple correct options A. copper B. Silver c. Gold D. zinc |
12 |
| 505 | When conc. ( boldsymbol{H}_{2} boldsymbol{S} boldsymbol{O}_{4} ) is electrolysed with high current using Pt electrodes, the product obtained at anode is: ( A cdot S O_{2} ) в. ( S O_{3} ) ( c cdot O_{2} ) D. ( H_{2} S O_{4} ) |
12 |
| 506 | Pb is a very important element of carbon family. It forms a number of compounds which are very useful in industries. The process of removal of base metals ( (mathrm{Cu}, mathrm{Sn}, mathrm{Bi}, mathrm{As}) ) from lead is called: A. softening process B. liquation c. parke’s process D. cupellalion |
12 |
| 507 | The process of extraction of metal from its ores, is known as: A. concentration B. calcination c. purification D. metallurgy |
12 |
| 508 | Any physical and chemical process by which low grade ores are concentrated, is A. froth flotation B. crushing and then screening c. hand picking D. washing in zigs |
12 |
| 509 | During the process of electrorefining of ( C u, ) some metals present as impurity settle as anode mud. These are: ( mathbf{A} cdot operatorname{Sn} ) and ( A g ) B. ( P b ) and ( Z n ) c. ( A g ) and ( A u ) D. Fe and ( N i ) |
12 |
| 510 | The flux used in the extraction of iron from haematite in blast furnace, is: A. limestone B. silica ( c cdot ) coke D. quartz |
12 |
| 511 | In the extraction of aluminium ; (i) name the process of concentration of bauxite. (ii) write the cathode reaction in electrolytic reduction of alumina. (iii) write the function and chemical formula of cryolite. (iv) write a chemical equation for the action of heat on aluminium hydroxide. (v) why is it necessary to replace anodes time to time? |
12 |
| 512 | Match the column (I) and (II) and select the correct answer using the codes given below. ColumnColumn-II (a) (1) Halide ore of magnesium Argentite (b) Cuprite (2) Carbonate ore of iron (c) Siderite (3) Oxide ore of copper (d) Carnallite (4) Sulphide ore of silver A. a-4, b-3, c-2 B. a-1, b-2, c-3, d-4 c. ( a-2, b-3, c-3, d-1 ) D. a-3, b-4, c-1 ( d-2 ) |
12 |
| 513 | In the extraction of nickel by Mond’s process, the metal is obtained by: A. electrochemical reduction B. thermal decomposition c. chemical reduction by aluminium D. reduction by carbon |
12 |
| 514 | Write down the reactions taking place in different zones in the blast furnace during the extraction of iron. |
12 |
| 515 | Zone-refining has been employed for preparing ultra-pure samples of: A. cu B. zn c. Ge D. Agg |
12 |
| 516 | white two basic requirements for refining of a metal by Mond’s process Q.31 Write two basic require and by van Arkel Method. Ans. Two basic requirements are |
12 |
| 517 | Casseterite ore consists of magnetic impurity named as: A. chromite B. wolframite c. magnetite D. Limonite |
12 |
| 518 | Which of the above metal oxide has the minimum thermal decomposition temperature? Cad O ( 3 . ) Fed ( c cdot Z r O_{2} ) D. ( M q ) |
12 |
| 519 | • 30 How is copper extracted from low grade copper ores: | 12 |
| 520 | Assertion Metals of high impurity are obtained by zone-refining. Reason Impurities in the ore are more soluble in the metal than in the pure metal Choose the correct option. 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 |
| 521 | Give one word or a phrase for the following statement: The process by which sulphide ore is concentrated: |
12 |
| 522 | Forth floatation process of concentration is based on the: A. preferential wetting properties with the frothing agent and water B. difference in the specific gravities of gangue and ore particles C. difference in solubility of ganaue and ore particles in frothing agent and water D. difference in reactivity of gangue and ore particles with water and frothing agent. |
12 |
| 523 | During extraction of Fe: A . carbon is ultimately converted to ( C O_{2} ) in the combustion zone in the blast furnace B. ( C O_{2} ) is one of the by-products of reduction zone of blast furnace C. cast iron is obtained from blast furnace D. uppermost zone of blast furnace is slag formation zone |
12 |
| 524 | Pyrolusite is a/an: A. oxide ore B. sulphide ore c. carbide ore D. not an ore |
12 |
| 525 | Explain the magnetic separation method. |
12 |
| 526 | Consider following equilibrium ( 3 F e(s)+C(s) rightleftharpoons F e_{3} C(s), quad Delta H^{circ}>0 ) What is the effect of increasing temperature on this equilibrium? A. reaction proceeds in forward c. no effects D. none of these |
12 |
| 527 | Mac Arthur process is used for the extraction of : A . Au ( c cdot c u ) D. zn |
12 |
| 528 | Question 25. What is the role of graphite rod in the electrometallurgy of aluminium? |
12 |
| 529 | Extraction of aluminium from aluminium oxide ( left(A l_{2} O_{3}right) ) is best done by: A. Electrolytic reduction of ( A l_{2} O_{3} ) B. Reduction of ( A l_{2} O_{3} ) with carbon c. Reduction of ( A l_{2} O_{3} ) with sodium D. Reduction of ( A l_{2} O_{3} ) with ( c o ) |
12 |
| 530 | Cinnabar ( (H g S) ) is heated in air, it is first converted into which is then reduced to on further heating A. ( H g O, H g ) в. ( H g O, H g_{2} O ) ( mathbf{c} cdot H g_{2} O, H g ) D. ( H g_{2} O, H g O ) |
12 |
| 531 | The method of concentration of the ore that makes use of difference in density between ore and impurities is called A. levigation B. leaching c. magnetic separation D. liquation |
12 |
| 532 | Which of the method used for the concentration of sulfide ores? A. froth floatation B. smelting c. magnetic separation D. gravity separation |
12 |
| 533 | In the extraction of iron from haematite, the charge used is haematite, coke and lime stone in the following weight ratio. A. 1: 1: 1 B. 8: 4: 1 ( c cdot 8: 1: 4 ) D. 1: 4: 8 |
12 |
| 534 | Lead is extracted from its chief ore galena by both carbon reduction as well as self-reduction. A. True B. False |
12 |
| 535 | What is the process of leaching in case of low grade copper ores? A . Leaching is carried out with ( N a O H ) and ( O_{2} ) B. Leaching is carried out with ( N a C N ) C. Leaching is carried out with acids in presence of ( O_{2} ) D. Leaching is carried out by boiling the ore with water |
12 |
| 536 | Mention the type of reaction to obtain ( boldsymbol{A} boldsymbol{u}(mathbf{s} 0 I) ) Reaction: ( mathbf{2} boldsymbol{A} boldsymbol{u} boldsymbol{C l}_{3}+mathbf{3} boldsymbol{H} boldsymbol{C} boldsymbol{H} boldsymbol{O}+mathbf{3} boldsymbol{H}_{2} boldsymbol{O} longrightarrow ) ( mathbf{2} boldsymbol{A} boldsymbol{u}(boldsymbol{s} boldsymbol{o l})+boldsymbol{3} boldsymbol{H} boldsymbol{O O H}+boldsymbol{6} boldsymbol{H} boldsymbol{C l} ) A. Hydrolysis B. Oxidation c. Reduction D. Double decomposition |
12 |
| 537 | Which of the following metal can be reduced by carbon reduction as well as self reduction? ( A cdot F e ) B. Al ( c cdot P b ) D. None of these |
12 |
| 538 | Sulphide ores of metals are usually concentrated by Froth Flotation process. Which one of the following sulphide ores offers and exception and is concentrated by chemical leaching? A. Sphalerite B. Argentite c. Galena D. copper pyritee |
12 |
| 539 | In blast furnace, haematite is reduced to iron mainly by: A. ( O_{2} ) gas B . ( H_{2} ) gas c. ( C O ) gas D. ( C l_{2} ) gas |
12 |
| 540 | Which one of the following elements constitutes a major impurity in pig iron? A. Silicon B. Oxygen c. sulphur D. Graphite |
12 |
| 541 | 0.8 In the metallurgy of aluminium ….. (a) Al3+ is oxidised to Al (s). (b) graphide anode is oxidised to carbon monoxide and carbon dioxide. (c) oxidation state of oxygen changes in the reaction at anode. (d) oxidation state of oxygen changes in the overall reaction involved in the process. allt letrolio tortomodinamaal vocal with lininen |
12 |
| 542 | Draw labelled diagram of Hall-Heroult Electrolytic cell for the extraction of aluminium. Write anode and cathode reactions. |
12 |
| 543 | Which of the above given metal oxides can be reduced by ( boldsymbol{F} boldsymbol{e} ) (reducing agent) to its respective metal at temperature ( boldsymbol{T}_{mathbf{1}} ) ? ( A cdot Z r O_{2} ) B. ( C a O ) ( c . M g O ) D. None of the above |
12 |
| 544 | The iron formed in the blast furnace is called: A. pig iron B. wrought iron c. steel D. cast iron |
12 |
| 545 | The incorrect statement is : A. Calamine and siderite are carbonates B. Argentite and cuprite are oxides C. zinc blende and iron pyrites are sulphides D. Malachite and azurite are ores of copper |
12 |
| 546 | Identify the pairs of metals and their ores from the folllowing | 12 |
| 547 | Corundum is mineral of Al. A . silicate B. oxide c. double salt D. sulphate |
12 |
| 548 | In the purification of zirconium by Van Arkel process which halogen is used? A. Flourine B. Chlorine c. Bromine D. lodine |
12 |
| 549 | From the following the metals that cannot be obtained by electrolysis of the aqueous solution of their salts are: A ( . A g ) в. ( C u ) c. ( M g ) D. ( A l ) |
12 |
| 550 | Which is the correct process-mineral matching in metallurgical extraction? This question has multiple correct options A. Leaching : Ag B. Zone-refining : Sn c. Liquation: ( operatorname{sn} ) D. Van Arkel : zr |
12 |
| 551 | Which one of the following element is present in the eyes of certain animals? A. zinc B. Copper c. Gold D. Potassium |
12 |
| 552 | The role of fluorspar ( left(C a F_{2}right) ) which is added during the electrolytic reduction of alumina dissolved in fused cryolite is: A. to act as a catalyst B. to make the fused mixture very conducting c. to increase the temperature of the melt D. to decrease the rate of oxidation of carbon at the anode |
12 |
| 553 | Write the chemical reactions involved in the process of extraction of Gold. Explain the role of dilute NaCN and Zn in this process. |
12 |
| 554 | How many moles of ( N i(C O)_{4} ) could be obtained from the CO produced by the reaction of ( 75.0 mathrm{g} ) of carbon? [Assume ( 100 % ) reaction and ( 100 % ) recovery in both steps and molar mass of ( mathrm{Ni}=59 mathrm{g} / mathrm{mol}] ) A . 6.25 B. 1.5625 c. 3.125 D. 25.0 |
12 |
| 555 | Question 14. Giving examples, differentiate between ‘roasting’ and ‘calcination’. Main point of difference is presence/absence of air. |
12 |
| 556 | The diagram shows the changes in state of water ( left(H_{2} Oright) . ) What is the process X called: A. Melting B. Freezing c. Boiling D. Evaporation |
12 |
| 557 | Assertion Silver may be prepared by using silver coins; in this process, coins are treated with ( H N O_{3} ) and then treated with ( H C l ) to get ( A g C l, ) but directly coins are not treated with ( boldsymbol{H} boldsymbol{C l} ) Reason HCl is not a good oxidizing agent. 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 |
| 558 | 41. In electro-refining, the pure metal is deposited on (1) vessel (2) electrolyte (3) cathode (4) anode |
12 |
| 559 | пополас (c) supette cuucппу суспіt аt о 1. Question 6. Name the common elements present in the anode mud in electrolytic refining of copper. Why are they so present? |
12 |
| 560 | The formula of the most abundant salt of sodium in nature is: A. ( N a N O_{3} ) B. ( N a C l ) ( mathbf{c} cdot N a_{2} C O_{3} ) D. ( N a_{2} S O_{4} ) |
12 |
| 561 | Mac Arthur process is used for: A ( . A g ) в. ( F e ) c. ( C l ) D. ( O_{2} ) |
12 |
| 562 | The name of the metal which is extracted from the ore is given below Mark the example which is not correct. A. Malachite – ( C u ) B. Calamine – ( Z n ) c. chlornite – ( C r ) D. Dolomite – ( A l ) |
12 |
| 563 | Tempering of steel: A. is the heating the steel to appropriate temperature and then cooling it rapidly B. increases mechanical strength C. changes ratio of carbon in cementite D. all of the above |
12 |
| 564 | Minerals from which metals can be preferably extracted are called: A. ores B. Source c. Alloy D. None of these |
12 |
| 565 | Calamine is an ore of : A. Iron B. copper c. Aluminium D. zinc |
12 |
| 566 | 1. The alloy brass consists of (a) Copper and Tin (b) Copper and Zinc (c) Copper and Aluminium (d) Tin and Lead |
12 |
| 567 | 9 Match the items of Column Twith items of Column II and assign the correct code. Column! Column II A Blisterred Cu 1. Aluminium B Blast furnace 22CuO + cu s 6CU + SO, c Reverberatory furnace 3. Iron D. Hall-Heroult process 4. FeO + SIO2 Fesiog 5. 2 CS + 30, 20UO+ 2502 Codes A B C D A A B C D 0. (a) 2 3 4 1 (b) 1 2 3 5 ore (c) 5 4 3 2 cow (d) 4 5 3 2 rol Ans (al 12 B 13 7 1 |
12 |
| 568 | Froth floatation process used for the concentration of sulphide ore: This question has multiple correct options ( mathbf{A} cdot ) is based on the difference in wettability of different minerals B. uses sodium ethyl xanthate ( left(C_{2} H_{5} O C S_{2} N aright) ) as a collector C. uses ( N a C N ) as depressant in the mixture of ( Z n S ) and ( P b S ) when ( Z n S ) forms soluble complex and ( P b S ) forms froth D. uses pine oil as frothing agent |
12 |
| 569 | The following reactions take place during the extraction of copper from copper ore: (a) ( 2 C u_{2} S(l)+3 O_{2}(g) rightarrow ) ( 2 C u_{2} O(l) 2 C u_{2} O(l)+2 S O_{2}(g) ) (b) ( 2 C u_{2} O(l)+C u_{2} S(l) rightarrow 6 C u(l)+ ) ( S O_{2}(g) ) If ( C u_{2} O ) and ( C u_{2} S ) act as oxidising and reducing agent respectively in reaction (b) then enter 1 else 0. |
12 |
| 570 | What is the role of collectors in froth flotation process? |
12 |
| 571 | In metallurgy, the concentration of ore is followed by the dressing of ore. A. True B. False |
12 |
| 572 | Q.5 Zone refining is based on the principle that …. (a) impurities of low boiling metals can be separated by distillation. (b) impurities are more soluble in molten metal than in solid metal. (c) different components of a mixture are differently adsorbed on an adsorbent. (d) vapours of volatile compound can be decomposed in pure metal. Latte |
12 |
| 573 | Question 8. Write chemical reactions taking place in the extraction of zinc from zinc blende. |
12 |
| 574 | Statement 1: Leaching is employed in the extraction of aluminium, silver and gold. Statement 2: During leaching, the impurities in the ore are chemically removed by dissolving them in a suitable reagent. A. Statement 1 and statement 2 are true and statement 2 is a correct explanation of statement 1 B. Statement 1 and statement 2 are true but statement 2 is not a correct explanation of statement 1 c. statement 1 is true and statement 2 is false. D. Statement1 is false and statement 2 is true |
12 |
| 575 | (a) Which solution is used for the leaching of silver metal in the presence of air in the metallurgy of silver? (b) Out of ‘C’ and ‘CO’, which is a better reducing agent at the lower temperature range in the blast furnace to extract iron from the oxide ore? |
12 |
| 576 | Which of the following mineral contains two metals? A. Carnallite B. Dolomite c. Asbestos D. All of the above |
12 |
| 577 | Given below are the steps for extraction of copper from its ore. The balance reaction involved in reduction of copper(l) oxide with copper(l) sulphide is given in the reaction below. [ mathbf{2} C u_{2} boldsymbol{O}+boldsymbol{C} boldsymbol{u}_{2} boldsymbol{S} stackrel{text {Heat}}{longrightarrow} boldsymbol{6} boldsymbol{C} boldsymbol{u}+boldsymbol{S} boldsymbol{O}_{2} ] This reaction is known as: A. auto-reduction B. catalytic- reduction c. acid reduction D. none of these |
12 |
| 578 | Based on the above Ellingham diagram, the formation of carbon monoxide from carbon can reduce the metal oxide to metal at a temperature the point of intersection of the two lines. 1. Equal to 2. Higher than 3. Lower than 4. None |
12 |
| 579 | Which of the following metal cannot occur in native state? A. ( C u ) в. ( A l ) ( c . A g ) D. None of the above |
12 |
| 580 | The method of zone refining of metals is based on the principle of: A. greater mobility of the pure metal than that of impurity B. higher melting point of the impurity than that of the pure metal C. greater noble character of the solid metal than that of the impurity D. greater solubility of the impurity in the molten state than in the solid state |
12 |
| 581 | In the Down’s process of obtaining sodium, ( C a C l_{2} ) is added: A. To get high yield of sodium B. To improve the quality of sodium obtained C. To lower the operating temperature D. To act as a reducing agent |
12 |
| 582 | Which method is used in the refining of Titanium metal? A. zone refining B. Mond carbonyl c. Frasch D. Van Arkel |
12 |
| 583 | Phosphorus mostly exists in free state. A. True B. False |
12 |
| 584 | Which of the following pair consists of ore of the same metal? This question has multiple correct options A. Magnesite, Cerussite B. Chalcocite, Copper pyrites c. Bauxite, Corundum D. Anglesitc, Cerussite |
12 |
| 585 | Assertion Extraction of metals from their ores by chemical methods requires the use of reducing agent. Reason Reducing agent helps to convert the metal oxide from its ore to the metal 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 |
| 586 | When ( F e C r_{2} O_{4} ) (chromite) is reduced with ( A l ) A ( cdot C r ) and ( F e_{2} O_{3}, ) are formed B. Fe and ( C r_{2} O_{3} ) are formed c. ( F e ) and ( C r ) (ferrochrome) are formed D. ( F e C r O_{4} ). is formed |
12 |
| 587 | Write down the chemical equations for metallurgical process to represent Roasting of galena (PbS) Chemical equation: ( 2 P b S+3 O_{2} rightarrow 2 P b O+2 S O_{2} ) ( boldsymbol{P b S}+mathbf{2 O}_{2} rightarrow boldsymbol{P b S O}_{4} ) If true enter 1 else 0 ( A ) |
12 |
| 588 | Which does not represent correct method? ( mathbf{A} cdot T i C l_{2}+2 M g rightarrow T i+2 M g C l_{2}: K r o l ) B. ( N i(C O)_{4} rightarrow N i+4 C O: ) Mond c. ( _{A g_{2}} C O_{3} rightarrow 2 A g+C O_{2}+frac{1}{2} O_{2}: ) van Arkel ( mathbf{D} cdot Z r l_{4} rightarrow Z r+2 I_{2}: ) van Arkel |
12 |
| 589 | Mercury has low boiling point. Therefore it can be purified by the process of: A. liquation B. polling c. oxidation D. distillation |
12 |
| 590 | The one that is not a carbonate is: A. bauxite B. siderite c. calamine D. malachite |
12 |
| 591 | For which of the following ores forth floatation method is used for concentration? A . Haematite B. zinc blende c. Magnetite D. carnallite |
12 |
| 592 | STATEMENT-1: Extraction of zinc from sphalerite ore involves the roasting followed by reduction with coke. STATEMENT-2:Zinc can be commercially extracted by hydrometallurgy. A. STATEMENT-1 is True, STATEMENT-2 is True: STATEMENT-2 is a correct explanation for STATEMENT- B. STATEMENT-1 is True, STATEMENT-2 is True: STATEMENT-2 is NOT a correct explanation for STATEMENT-1 c. STATEMENT-1 is True, STATEMENT-2 is False D. STATEMENT-1 is False, STATEMENT-2 is True |
12 |
| 593 | Which of the following metals is not extracted by leaching? A. Aluminium B. Mercury c. silver D. Gold |
12 |
| 594 | Assertion In cyanide process for the extraction of gold and silver from their native ores, the cyanide solution acts as a reducing agent to reduce the gold and silver compounds present in the ores into the metallic states. Reason In the extraction of gold and silver, the cyanide solution acts as complexing reagent in the presence of air and form their respective soluble complexes. 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 |
| 595 | Fill in the blanks with the correct choice. The undesired impurities present in the the volatile impurities from the ore, the (ii) process is carried out. Flux combines with non-fusible impurities to form (iii) ( C a O ) acts as a (iv) flux. A. (i) – gangue, (iii) – slag, (iv) -acidic (ii) -roasting, (ii) – calcination, (iii) – slag, (iv) – basic B. (i) – gangue, c. (i) – anode mud, (ii) – – leaching, (iii) – matrix, (iv) -acidic D. (i) – gangue, (ii) -roasting, (iii) – solution, (iv) -acidic |
12 |
| 596 | Silver ore dissolves in dilute solution of NaCN in the presence of air to form: A ( . A g C N ) В ( cdotleft[A g(C N)_{2}right]^{-} ) c. ( A g S C N ) ( mathbf{D} cdotleft[A g(C N)_{4}right] ) |
12 |
| 597 | Below point ‘A’ FeO can A. be reduced by carbon monoxide only B. be reduced by both carbon monoxide and carbon c. be reduced by carbon only D. not be reduced by both carbon monoxide and carbon |
12 |
| 598 | The element which could be extracted by electrolytic reduction of its oxide dissolved in a high temperature melt is: A. Sodium B. Potassium c. Fluorine D. Aluminium |
12 |
| 599 | The above process is: [ begin{array}{c} boldsymbol{H} boldsymbol{g} boldsymbol{S} stackrel{boldsymbol{O}_{2}}{longrightarrow} boldsymbol{H} boldsymbol{g} boldsymbol{S} cdot boldsymbol{H} boldsymbol{g} boldsymbol{O} \ & downarrow boldsymbol{Delta} \ boldsymbol{H} boldsymbol{g} end{array} ] A. auto oxidation B. self reduction c. thermal reduction D. none of the above |
12 |
| 600 | Name of the process is cyanide process, in which we added Zn to soluble ( left[boldsymbol{A} boldsymbol{g}(boldsymbol{C N})_{2}right]^{-} ) to get Ag. If true enter 1 else 0. |
12 |
| 601 | ning (resort Last um Q. 35 The mixture of compounds A and B is passed through a column of AL23 by using alcohol as eluant. Compound A is eluted in preference to compound B. Which of the compounds A or B, is more readily adsorbed on the column? |
12 |
| 602 | Select the correct statement(s). This question has multiple correct options A. In hydrometallurgy, ( Z n ) is used as oxidizing agent in the purification of ( A g ) from ( left[A g(C N)_{2}right]^{circ} ) B. When pine oil or eucalyptus oil is added into the water, it lowers down the surface tunsion by which froth is formed C. Sodium ethyl xanthate is used as collector D. Basic copper carbonate or ( P b S O_{4} ) is concentrated by froth floatation method by using an activator |
12 |
| 603 | Early transition metals occur in nature as oxides but the late transition metals occur as sulphides. If it is true enter 1 , else enter 0 |
12 |
| 604 | Bessemer converter is used for the preparation of A. steel B. Wrought iron c. Pig iron D. cast iron |
12 |
| 605 | During calcination: A. carbonate ores are changed into oixdes B. oxide ores are changed into carbonates C. carbonate ores are changed into sulhides D. oxide ores are changed into sulphides |
12 |
| 606 | 6. The chief ore of iron is. |
12 |
| 607 | Cassiterite is an ore of: A. Mn B. Ni ( c cdot s b ) D. sn |
12 |
| 608 | Purification of aluminium by electrolytic refining is called: A. Serpeck’s process B. Hoope’s process c. Hall’s process D. Baeyer’s process |
12 |
| 609 | Which of the following two substances react to produce blister copper? ( mathbf{A} cdot C u_{2} S_{(s)} ) and ( C u_{2} O_{(s)} ) B. ( C u_{2} O_{(s)} ) and ( F e S_{S_{s}} ) c. ( C u_{2} S_{(s)} ) and ( O_{2(g)} ) D. ( C u_{2} S_{(s)} ) and ( F e S_{2(s)} ) |
12 |
| 610 | Which of the following process is not a physical process of separation? A . Levigation B. Magnetic separation c. Leaching D. Froth fioatation |
12 |
| 611 | Name the refining method used to produce semiconductors. | 12 |
| 612 | column Il. 27. Column 1 (A) Iron (B) Aluminium (C) Tin (D) Silver A B (a) s (b) p q (c) 9 S (d) T 4 Column II (p) Refining by liquation (9) Electrolyte refining (r) Reduction by smelting (s) Leaching D 4,5 T C P S P r |
12 |
| 613 | Zone refining is based on the principle that A. impurities of low boiling metals can be separated by distillation B. impurities are more soluble in molten metal than in solid metal C. different component of a mixture are differently adsorbed on an adsorbent D. vapours of volatile compound can be decomposed in pure metal |
12 |
| 614 | 23. Magnetic separation is used to increase concentration of (a) Horn Silver (b) Calcite (c) Haematite (d) Magnesite |
12 |
| 615 | State True or False. In the purification of bauxite ore as a preliminary step in the production of ( A l ) ( left.[boldsymbol{A l}](boldsymbol{O H})_{4}right]^{-} ) can be converted to ( A l(O H)_{3} ) by passing ( C O_{2} ) through it. |
12 |
| 616 | A number of elements are available in earth’s crust but most abundant elements are ( mathbf{A} cdot A l ) and ( F e ) B. Fe and ( C u ) c. ( C u ) and ( A g ) D. none of these |
12 |
| 617 | In this method, a low melting metal like tin can be made to flow on a sloping surface. In this way it is separated from higher melting impurities. The method is known as: A. distillation B. vapour phase refining c. liquation D. zone refining |
12 |
| 618 | Which if the following is a common reducing agent for extracting metals from ore? A. ( C O ) B. Carbon c. Hydrogen D. All of the above |
12 |
| 619 | Write the name of the metal whose ore is siderite. |
12 |
| 620 | Partial roasting of galena gives: A. Only PbS B. Only Pbo c. ( P b S+P b O ) ( mathbf{D} cdot P b O+P b ) |
12 |
| 621 | Magnetite does not contain ( M g ? ) A. True B. False |
12 |
| 622 | At what approximate temperature, zinc and carbon have equal affinity for oxygen? A ( cdot 1000^{circ} mathrm{C} ) В. ( 1500^{circ} mathrm{C} ) ( c cdot 500^{circ} C ) D. ( 1200^{circ} mathrm{C} ) |
12 |
| 623 | Which of the following ore contains both copper and iron? A. Cuprite B. Chalcocite c. chalcopyrite D. Malachite |
12 |
| 624 | In Bessemer converter, ( boldsymbol{C} boldsymbol{u}_{2} boldsymbol{S} ) is converted to blister copper by: A. self reduction B. reduction with coke c. reduction with coal gas D. reduction with ( H_{2} ) gas |
12 |
| 625 | Anodic product in the electrolytic reduction of alumina is: A. ( C O_{2}, quad O_{2} ) в. ( O_{2} ) ( c cdot F_{2} ) D. ( O_{2}, quad 4 F_{2} ) |
12 |
| 626 | Assertion Aluminium a good reducing agent. Reason Aluminium has strong affinity for oxygen and is thus readily oxidized. |
12 |
| 627 | The thickness of cathode increases in : A . electrorefining of copper B. electroplating of copper c. anodizing of copper D. none of the above |
12 |
| 628 | Assertion Statement-I: Wolframite impurities are separated from cassiterite by electromagnetic separation. Reason Statement- II : Cassiterite being magnetic is attached by the magnet and forms a separate heap. 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 |
| 629 | 0.51 Assertion (A) Zirconium can be purified by van Arkel method. Reason (R) ZrI, is volatile and decomposes at 1800K. |
12 |
| 630 | Which one of the following oxides is reduced by water gas to obtain the metal during its extraction? A. ( N i O ) в. ( Z n O ) c. ( W O_{3} ) D. ( F e_{2} O_{3} ) |
12 |
| 631 | The metal oxide which cannot be reduced to metal by carbon is A ( . Z n O ) в. ( F e_{2} O_{3} ) ( c . P b O ) D. ( A l_{2} O_{3} ) |
12 |
| 632 | Mac Arthur process is used for the extraction of: A . ( A u ) в. ( P t ) c. ( C u ) D. ( Z n ) |
12 |
| 633 | Blister copper is: A. impure copper B. obtained in self-reduction process during bessemerisation c. both are correct D. none is correct |
12 |
| 634 | Chromatography is a useful method for purification of elements which are: A. very reactive B. available in minute quantities c. present in abundance D. highly electropositive |
12 |
| 635 | Blister copper is the purest form of copper having a blister like surface due to the release of gas during cooling. If true enter 1 , else enter 0 . |
12 |
| 636 | Which of the following metals is obtained by leaching the ore with dilute cyanide solution? A. Silver B. Titanium c. Vanadium D. zinç |
12 |
| 637 | Differentiate between roasting and calcination. |
12 |
| 638 | Metallurgy involves steps:- This question has multiple correct options A. Concentration of ore B. Oxidation of ore C. Purification D. Reduction of ore |
12 |
| 639 | Find out ( E: ) ( mathbf{A} cdot N a_{3} G e F_{6} ) ( mathbf{B} cdot N a_{3} A l F_{6} ) ( mathbf{C} cdot A l_{2} O_{3} ) D. none of these |
12 |
| 640 | Copper matte is a molten mixture of : A ( cdot C u_{2} S+F e S(text { little }) ) в. ( C u_{2} S+ ) Fe ( O ) (little) ( mathrm{c} cdot mathrm{Cu}_{2} mathrm{O}+mathrm{FeO} ) (little) D. ( C u_{2} O+F e S(text { little }) ) |
12 |
| 641 | Which mineral has been named incorrectly? A. Bauxite ( : A l_{2} O_{3} cdot 2 H_{2} O ) B. Corundum: ( A l_{2} O_{3} ) C . Cryolite ( : 3 mathrm{NaF} cdot mathrm{AlF}_{3} ) D. Feldspar: ( B e_{3} A l_{2} S i_{5} O_{18} ) |
12 |
| 642 | The following flow chart represents the extraction of Froth flotation ( t ) Roasting ( t ) Smelting ( t ) Bessemerization ( t ) Electrolytic refining A. Copper B. zinç c. Iron D. Aluminium |
12 |
| 643 | Among the following processes, how many are employed for the extraction of lead from ore galena? (i) Self reduction (ii) Carbon reduction (iii) Metal displacement method, (iv) electrolytic reduction , (v) Carbon monoxide reduction, (vi) Hydrogen reduction |
12 |
| 644 | the mass of carbon anode consumed (giving only carbon dioxide) in the production of ( 270 K g ) of aluminium metal from bauxite by the Hall’s process is: ( mathbf{2} boldsymbol{A} boldsymbol{l}_{2} boldsymbol{O}_{3}+mathbf{3} boldsymbol{C} rightarrow mathbf{4} boldsymbol{A} boldsymbol{l}+mathbf{3} boldsymbol{C} boldsymbol{O}_{2} ) A. ( 180 mathrm{Kg} ) в. ( 270 K g ) c. ( 240 K g ) D. ( 90 K g ) |
12 |
| 645 | Which of the following metal is purified by Mond carbonyl method? ( mathbf{A} cdot T i ) в. ( G e ) ( c cdot Z r ) D. ( N i ) |
12 |
| 646 | The chemical formula of diaspore, an ore of aluminium, is: A. ( A l_{2} O_{3} .3 H_{2} O ) в. ( A l_{2} O_{3} .2 H_{2} O ) c. ( A l_{2} O_{3} . H_{2} O ) D. ( A l_{2} O_{3} ) |
12 |
| 647 | In the equation, ( 4 M+8 C N^{-}+ ) ( mathbf{2} boldsymbol{H}_{2} boldsymbol{O}+boldsymbol{O}_{2} rightarrow boldsymbol{4}left[boldsymbol{M}(boldsymbol{C} boldsymbol{N})_{2}right]^{-}+mathbf{4} boldsymbol{O} boldsymbol{H}^{-} ) Identify the metal ( mathrm{M} ) A. copper B. Iron c. Gold D. zinc |
12 |
| 648 | Following reaction is reversible ( A g_{2} S+4 N a C N rightleftharpoons 2 N aleft[A g(C N)_{2}right]+ ) ( N a_{2} S ) When we pass air this reaction become spontaneous. A. True B. False |
12 |
| 649 | Thomas slag is: A ( cdot C a_{3}left(P O_{4}right)_{2} cdot 2 H_{2} O ) в. ( C a_{3}left(P O_{4}right)_{2} cdot ) Са ( operatorname{Si} O_{3} ) ( mathbf{c} cdot M g S i O_{3} ) D. ( operatorname{casi} O_{3} ) |
12 |
| 650 | ( X C l_{2}(text { excess })+Y C l_{2} rightarrow X C l_{4}+Y downarrow ) ( boldsymbol{Y} boldsymbol{O} frac{Delta}{>400^{0}} frac{1}{2} boldsymbol{O}_{2}+boldsymbol{Y} ) Ore of ( Y ) would be : A. Siderite B. Cinnabar c. Malachite D. Hornsilver |
12 |
| 651 | In the bessemerisation of sulphide ore of copper, there is self-reduction giving copper metal. If true enter 1 , else enter 0 . |
12 |
| 652 | What products are formed during, the electrolysis of a concentrated aqueous solution of ( N a C l ? ) (I) ( C l_{2} ) (II) ( N a O H(a q) ) ( (| I) H_{2}(g) ) A. I only B. I and II only C. ( I ) and ( I I I ) only D. I, II and III |
12 |
| 653 | The collecting agent in froth floatation process is: A. sodium ethyl xanthate B. pine oil c. lime D. water |
12 |
| 654 | Formula of feldspar is: A. ( K_{2} O . A l_{2} O_{3} .6 S i O_{2} ) B. ( K_{2} O_{3} . A l_{2} O_{3} .6 s i_{2} O_{2} .2 H_{2} O ) c. ( A l_{2} O_{3} .2 S i O_{2} .2 H_{2} O ) D. ( 3 M g O .4 S i O_{2} . H_{2} O ) |
12 |
| 655 | Na is obtained by the electrolysis of aqueous NaCl solution. 1. True 2. False |
12 |
| 656 | Question 10. Which method is used to refine Zr and Ti? Explain with equation. |
12 |
| 657 | How is gold extracted from its ore? | 12 |
| 658 | What is the action of carbon on the following metal oxide. ( F e_{2} O_{3} ) in blast furnace |
12 |
| 659 | 0.6 In the extraction of copper from its sulphide ore, the metal is formed by the reduction of Cu O with (a) Fes (b) CO (c) Cu s (d) SO2 In the extraction of copper from its sulphide ore the metal is formed by the reduct |
12 |
| 660 | Which of the following metal is sometimes found native in nature? A. Aluminium B. Copper c. sodium D. Magnesium |
12 |
| 661 | Which of the following molecular formulae represent the ore carnallite? A. ( N a_{2} A l_{2} O_{4} ) в. ( N a_{3} A l F_{6} ) c. ( K C l M g C l_{2} cdot 6 H_{2} O ) D. ( F e_{3} O_{4} ) |
12 |
| 662 | The choice of a reducing agent in a particular case depends on thermodynamic factor. How far do you agree with this statement? Support your opinion with two examples. | 12 |
| 663 | Extraction of gold and silver involves leaching the metal with ( C N^{-} ) ion. The metal is recovered by: A. displacement of metal by some other metal from the complex ion B. roasting of metal complex c. calcination followed by roasting D. thermal decomposition of metal complex |
12 |
| 664 | Leaching of ( A g_{2} S ) is carried out by heating it with a dilute solution of: A. ( N a C N ) only в. НС l c. ( N a O H ) D. ( N a C N ) in presence of ( O_{2} ) |
12 |
| 665 | Heating a mixture of ( C u_{2} O ) and ( C u_{2} S ) will give. A. ( C u O+C u S ) в. ( C u+S O_{3} ) c. ( C u+S O_{2} ) D. ( C u(O H)_{2}+C u S O_{4} ) |
12 |
| 666 | The metal that is present in brass, bronze, and German silver is : ( A cdot ) Mg B. zn ( c cdot c u ) ( D cdot A ) |
12 |
| 667 | Question 9. Why are sulphide ores converted to oxides before reduction? |
12 |
| 668 | Boron can be obtained by various methods but not by A. Thermal decomposition of ( B_{2} H_{6} ) B. Pyrolysis of ( B I_{3} ) (van Arkel) C. Reducing ( B C l_{3} ) with ( H_{2} ) D. Electrolysis of fused ( B C l_{3} ) |
12 |
| 669 | The principle of fractional crystallisation is involved in which one of the following processes? A. Van Arkel’s method B. Distillation c. cupellation D. zone refining |
12 |
| 670 | The metal oxide reacts with a The oxide is metal and reducing agent is Net Gibb’s energy changes is A. reducing agent, oxidised, reduced, negative B. reducing agent, reduced, oxidised, negative c. oxidising agent, reduced, oxidised, positive D. reducing agent, reduced, oxidised, positive |
12 |
| 671 | When a solid melts, the temperature: A. increases B. decreases c. remains same D. can’t say |
12 |
| 672 | Which of the following methods is used in purification of mercury? A. Liquation B. Distillation c. Electrolytic refining D. Chemical reduction |
12 |
| 673 | Match column A with column B and select the correct option- |
12 |
| 674 | Which of the following benefication processes is used for the mineral, ( A l_{2} O_{3} cdot 2 H_{2} O ? ) A. Froth-flotation B. Liquation c. Leaching D. Magnetic separation |
12 |
| 675 | Assertion Statement-I: Lead, tin and bismuth are purified by liquation method. Reason Statement- -II : Lead, tin and bismuth have low m.p. as compared to impurities. Read the above assertion and reason and choose the correct option regarding ¡t. 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 |
| 676 | Fe, Ti and Sn metals are found in nature as? A. Sulphide ores B. Oxide ores c. Native D. Silicate ores |
12 |
| 677 | Which of the following reactions can take place in the reverberatory furnace? A. ( z n 0+c rightarrow z n+c 0 ) B. ( 2 mathrm{Cu}_{2} mathrm{S}+3 mathrm{O}_{2} rightarrow 2 mathrm{Cu}_{2} mathrm{O}+2 mathrm{SO}_{2} ) ( mathrm{c} cdot mathrm{HgS}+mathrm{O}_{2} rightarrow mathrm{Hg}+mathrm{SO}_{2} ) D. ( mathrm{PbCO}_{3} rightarrow mathrm{PbO}+mathrm{CO}_{2} ) |
12 |
| 678 | Among the methods for extracting metals from their ores, i.e., ( 1 . ) roasting a metal sulphide, 2. chemical reduction of a metal oxide, and 3. electrolysis, the preferred method depends on ( E^{circ} ) value for the reducing half-reaction: ( M^{n+}(a q)+n e^{-} rightarrow M(s) ) Which method is preferred for the metals with the most negative ( E^{circ} ) values? |
12 |
| 679 | There are following extraction process of silver but not: A. as a side product in electrolytic refining of copper B. Parkes process in which ( Z n ) is used to extract silver by solvent extraction from molten lead C. by reaction of silver sulphide with ( K C N ) and then the reaction of a soluble complex with ( Z n ) D. by heating ( N aleft[A g(C N)_{2}right] ) |
12 |
| 680 | 0.39 What should be the considerations during the extraction of metals by electrochemical method? |
12 |
| 681 | Question 13. How can you separate alumina from silica in a bauxite ore associated with silica? Give equations, if any. Describe Baeyer’s process: |
12 |
| 682 | . 16 In the extraction of aluminium by Hall-Heroult process, purified Al203 is mixed with CaF, to (a) lower the melting point of AI,O, (b) increase the conductivity of molten mixture. (c) reduce AP+ into Al(s) (d) acts as catalyst |
12 |
| 683 | Which of the following metal is not manufactured by electrolysis? A . Na a в. Мв ( c cdot A ) D. Fe |
12 |
| 684 | Which of the following reactions represent correct method? This question has multiple correct options |
12 |
| 685 | During electrolytic refining of Alumina, the molten electrolyte used contains A. cryolite B. Fluorspar c. Pure alumina D. All of the above |
12 |
| 686 | A mixture of sand and salt can be separated by: A. Sublimation B. Sieving c. Dissolving salt and sand mixture in water and then filtration D. Dissolving salt in water and then distillation |
12 |
| 687 | Assertion Copper obtained after bessemerization is known as blister copper. Reason Blisters are produced on the surface of the metal due to escaping of dissolved ( boldsymbol{S O}_{2} ) 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 |
| 688 | The chemical composition of slag formed during the smelting process in the extraction of copper is: A ( cdot C u_{2} O+F e S ) в. Fesi Оз( _{3} ) ( mathbf{c} cdot mathrm{CuFeS}_{2} ) D. ( C u_{2} S+ ) Fe( O ) |
12 |
| 689 | Metallurgical process of zinc involves roasting of zinc sulphide followed by reduction. Metallic zinc distills over as it is volatile and impurities like ( mathrm{Cu}, mathrm{Pd} ) and Fe gets condensed. The crude metal obtained is called spelter, which may be purified by: This question has multiple correct options A . electrolysis process B. fractional distillation c. polling D. heating with iodine |
12 |
| 690 | Which of the following gases is responsible for the flame at the mouth of Bessemer converter? A. Carbon monoxide B. Carbon dioxide c. Chlorine D. oxygen |
12 |
| 691 | In the extraction of copper, the smelt formed in the blast furnace contains: A. ( C u_{2} S+ ) little ( F e S ) в. ( C u_{2} S+ ) little ( F e O ) c. ( C u_{2} O+ ) little ( F e S ) D. ( C u_{2} O+ ) little ( F e O ) |
12 |
| 692 | Zinc Blende is concentrated by: A. chemical separation B. magnetic speciation C. froth floatation D. hydraulic washing |
12 |
| 693 | 14. Roasting is generally done in case of the following (a) Oxide ores () Silicate ores (c) Sulphide ores (d) Carbonate ores |
12 |
| 694 | Name the processes from which chlorine is obtained as a by-product What will happen if an aqueous solution of ( N a C l ) is subjected to electrolysis? |
12 |
| 695 | State whether the given statement is True or False. ( C u O ) can’t be reduced by carbon but it can be reduced by ( H_{2} ) ( operatorname{given}: Delta G_{f}^{circ} ) for ( C u O=-129.7 mathrm{kJ} mathrm{mol}^{-1} ) ( C O=-137.2 mathrm{kJ} mathrm{mol}^{-1} mathrm{H}_{2} mathrm{O}=-237.2 mathrm{kJ} ) ( m o l^{1} ) |
12 |
| 696 | Extracti ion. ction of gold and silver involves leaching the metal with CN The metal is recovered by (a) displacement of metal by some other metal from the complex ion. (b) roasting of metal complex. (c) calcination followed by roasting. (d) thermal decomposition of metal complex. Then The motel in |
12 |
| 697 | Minerals having Fe is : A. Magnetite B. Pyrites c. spathic iron D. All of these |
12 |
| 698 | Chromium and manganese oxides are reduced to metals by using: A. aluminium B. iron c. silver D. chromium |
12 |
| 699 | 32 Although carbon and hydrogen are better reducing agents but they are not used to reduce metallic oxides at high temperatures. Why? OSN Ans Because at hiabi tolo to form carbiden |
12 |
| 700 | Describe a method for refining nickel | 12 |
| 701 | In the cyanide extraction process of silver from argentite ore, the oxidizing and reducing agents used are: A. ( O_{2} ) and ( C O, ) respectively B. ( O_{2} ) and ( Z n ) dust, respectively c. ( H N O_{3} ) and ( Z n ) dust, respectively D. ( H N O_{3} ) and ( C O, ) respectively |
12 |
| 702 | Down’s method is used for the extraction of : A . ( A l ) в. ( N a ) ( mathrm{c} cdot M g ) D. ( C u ) |
12 |
| 703 | Question 21. The value of A,G°for formation of Cr, O, is – 540 kJ/mol and that of Al2O3 is – 827 kJ/mol. Is the reduction of Cr,03 possible with AI? Find AGº for both the forward and reverse reactions, if A. Gº is negative. reaction is feasible. |
12 |
| 704 | The chemical process in the production of steel from haematite ore involves A. reduction B. oxidation c. reduction followed by oxidation D. oxidation followed by reduction |
12 |
| 705 | Select correct statement. A. Based on reactivity series, occurrence of certain elements takes place in native state B. Due to basic nature of oxides of alkaline earth elements, they combine with atmospheric acidic oxides giving salts c. Both (a) and (b) are correct D. None of the above is correct |
12 |
| 706 | Assertion: For the extraction of iron, haematite ore is used. Reason: Haematite is a carbonate ore |
12 |
| 707 | Gold does not occur in the combined form. It does not react with air or water. It is in the ( _{text {一一一十日 }} ) A. native B. combined c. original D. liquid |
12 |
| 708 | Which of the following is not an iron ore? A. Malachite B. Haematite c. siderite D. limonite |
12 |
| 709 | What is the role of depressant in froth floatation process? |
12 |
| 710 | Although ( A u ) is soluble in aqua regia but ( A g ) is not. Explain. |
12 |
| 711 | Question 20. Why is zinc not extracted from zinc oxide through reduction using CO? (1) Consider Ellingham diagram and find the AGº for the formation of ZnO from Zn and Co, from CO. (ii) For a process to be spontaneous AGºmust be negative. |
12 |
| 712 | Which reaction occurs in blast furnace at ( 1270 K ) temperature? ( A cdot 3 F e_{2} O_{3}+C O rightarrow ) в. ( F e_{3} O_{4}+C O ) c. ( F e_{2} O_{3}+C O rightarrow ) D. ( F e O+C O rightarrow ) |
12 |
| 713 | Why is zinc not extracted from zinc oxide through reduction using ( C O ? ) |
12 |
| 714 | Which of the following reactions does not take place during leaching for concentration of bauxite? A ( cdot A l_{2} O_{3}+2 N a O H+3 H_{2} O rightarrow 2 N aleft[A l(O H)_{4}right. ) B . ( 2 mathrm{Na}left[mathrm{Al}(mathrm{OH})_{4}right]+mathrm{CO}_{2} rightarrow mathrm{Al}_{2} mathrm{O}_{3} . mathrm{xH}_{2} mathrm{O}+2 mathrm{NaHCO}_{3} ) c. ( A l_{2} O_{3} .2 H_{2} O stackrel{Delta}{longrightarrow} A l_{2} O_{3}+2 H_{2} O ) D. ( A l_{2} O_{3} cdot x H_{2} O stackrel{Delta}{longrightarrow} A l_{2} O_{3}+x H_{2} O ) |
12 |
| 715 | When bauxite is boiled with aqueous NaOH solution, sodium metal aluminate solution is formed. This part in the metallurgy of aluminium is called: A. liquation B. amalgamation c. leaching D. calcination |
12 |
| 716 | The correct statements with respect to Ellingham’s diagram among the following are (I) Magnesium reduces aluminium oxide below ( 1700 mathrm{K} ) (II) Aluminium reduces magnesium oxide above ( 1700 mathrm{K} ) (III) Aluminium reduces magnesium oxide below ( 1700 mathrm{K} ) (IV) Magnesium reduces aluminium oxide above ( 1700 mathrm{K} ) ( A cdot|&| mid ) B. ॥ & ॥ I c. III & IV D. II, III & IV |
12 |
| 717 | Select the correct statement. A. During the decomposition of an oxide into oxygen and metal vapour, entropy increases. B. Decomposition of an oxide is an endothermic change. C . To make ( triangle G^{0} ) negative, temperature should be high enough so that ( T triangle S^{0}>triangle H^{0} ) D. All are correct answers. |
12 |
| 718 | Oxides of the various metals are converted into metal by heating but not in : A. ( A g_{2} O ) B. Cuo c. Hgo D. all are correct |
12 |
| 719 | The metal obtained in the Pidgeon process is: A. ( N a ) в. ( M g ) ( c . C a ) D. ( A l ) |
12 |
| 720 | List I A. Van Arkel’s ( quad ) 1. Refining of silver method B. Solvay process 2. Purification of titanium 3. Manufacture of C. Cupellation [ N a_{2} C O_{3} ] 4. Purification of copper D. Poling Match List I with List II select the correct answer using the codes gives below the lists: A . A-2, B-1, C-3, D-4 B. ( A-4, B-3, C-2, D-5 ) c. ( A-2, B-3, C-1, D-4 ) D. A-5, B-1, C-3, D-4 |
12 |
| 721 | Which of the following reduction reactions are actually employed in commerical extraction of metals? This question has multiple correct options ( mathbf{A} cdot F e_{2} O_{3}+2 A l rightarrow A l_{2} O_{3}+2 F e ) B. ( C r_{2} O_{3}+2 A l rightarrow A l_{2} O_{3}+2 C r ) ( mathbf{c} cdot 2 N aleft[A u(C N)_{2}right]+Z n rightarrow N a_{2}left[Z n(C N)_{4}right]+2 A u ) ( mathbf{D} cdot C u_{2} S+P b rightarrow C u+P b S downarrow ) |
12 |
| 722 | (i) Name the method of refining to obtain silicon of high purity. (ii) What is the role of ( S i O_{2} ) in the extraction of copper? (iii) What is the role of depressants in froth floatation process? |
12 |
| 723 | Find the number of metals from the given metals which can be commercially purified by zone refining methods: ( (mathrm{Si}, mathrm{Ge}, mathrm{Ga}, mathrm{Al}, mathrm{Ti}, mathrm{Zr}) ) |
12 |
| 724 | Column – I What is and İ ( x ) Magnetic A. ( A g_{2} S ) separation ” ( Y ) Forth Flotation B. [ mathrm{FeCr}_{2} mathrm{O}_{4} ] ( z ) Gravity c. separation ( A l_{2}left(S i O_{3}right)_{3} ) Match the method of concentration of the ore in column I with the ore in column II and select the correct alternate: A ( . X-A, Y-B, Z-C ) B. ( X-B, Y-A, Z-C ) c. ( X-C, Y-A, Z-B ) D. ( X-B, Y-C, Z-A ) |
12 |
| 725 | Q. 43 Give two requirements for vapour phase refining. | 12 |
| 726 | During extraction of iron, which of the following reaction(s) exhibit development of elemental impurities in iron? This question has multiple correct options A. ( C a O+S i O_{2} rightarrow C a S i O_{3} ) в. ( M n O_{2}+C stackrel{Delta}{longrightarrow} M n+C O ) ( mathrm{c} cdot mathrm{Ca}_{3}left(mathrm{PO}_{4}right)_{2} stackrel{Delta}{longrightarrow} P_{4} mathrm{O}_{10} frac{mathrm{C}}{Delta} P_{4} ) D. ( operatorname{si} O_{2}+2 C stackrel{Delta}{longrightarrow} S i+2 C O uparrow ) |
12 |
| 727 | Assertion Van-Arkel method is used to prepare samples of some metals. Reason It involves the reaction of ( mathrm{CO} ) with metals to form volatile carbonyls that decompose on heating to give pure metal Read the above assertion and reason |
12 |
| 728 | A. Carnallite 1. Zinc B. Calamine 2. Titanium C. Limonite 3. Magnesium D. Chalcopyrite 4. Copper Match List I with List II and select the correct answer using the codes given below the lists. A. A-1,B-3,C-2,D-4 B. A-1,B-3,C-4,D-2 C . A-3,B-1,C-4,D-2 D. A-3,B-1,C-2,D-4 |
12 |
| 729 | What is the principle of zone refining of metals? A. Greater mobility of the pure metal than that of the impurity B. Higher melting point of the impurity than that of the pure metal c. Greater noble character of the solid metal than that of the impurity D. Greater solubility of the impurity in the molten state than in the solid |
12 |
| 730 | Copper is extracted from the ore copper pyrite by smelting in a blast furnace. The flux used and the slag formed are : ( mathbf{A} cdot f mid mathbf{u} times C a O, operatorname{slag} C a S i O_{3} ) B. flux ( S i O_{2}, ) slag ( C a S i O_{3} ) c. flux ( F e O ), slag ( F e S i O_{3} ) D. flux ( operatorname{Si} O_{2} ),slag ( F e S i O_{3} ) |
12 |
| 731 | The final step for the extraction of copper from copper pyrites in Bessemer converter the reaction involves is as: A ( cdot C u_{2} S+2 F e O rightarrow 2 C u+2 F e+S O_{2} ) в. ( C u_{2} S+2 C u O rightarrow 6 C u+S O_{2} ) c. ( 4 C u_{2} S+F e S rightarrow 8 C u+2 F e S O_{4} ) D. ( 2 C u_{2} O+F e S rightarrow 4 C u+2 F e+S O_{2} ) |
12 |
| 732 | Monds process is used for the purification of |
12 |
| 733 | In the purification of zirconium by van Arkel process which halogen is used? A. Fluorine B. Chlorine c. Bromine D. lodine |
12 |
| 734 | Four reactions that take place in the blast furnace to produce iron are shown. Which reaction is used to keep the furnace hot? A. ( C+O_{2} rightarrow C O_{2} ) в. ( C O_{2}+C rightarrow 2 C O ) c. ( F e_{2} O_{3}+3 C rightarrow 2 F e+3 C O ) D. ( F e_{2} O_{3}+3 C O rightarrow 2 F e+3 C O_{2} ) |
12 |
| 735 | Which one of the following ores is best concentrated by froth floatation method? A. Siderite B. Galena c. Malachite D. Magnetite |
12 |
| 736 | The slag obtained during the extraction of copper from copper pyrites is composed of A. ( C u_{2} S ) в. ( C u S i O_{3} ) c. ( F e S i O_{3} ) D. ( operatorname{si} 0_{2} ) |
12 |
| 737 | In the leaching of ( A g_{2} S ) with ( N a C N, ) a stream of air is also passed. It is because of: A. Reversible nature of reaction between ( A g_{2} S ) and NaCN B. To oxidise ( N a_{2} S ) into ( N a_{2} S O_{4} ) c. Both (A) and (B) D. None of the above |
12 |
| 738 | Which of the following metals cannot be used in electrolysis? A. Sodium B. Potassium c. Magnesium D. zinç |
12 |
| 739 | Leaching method is used to concentrate the ores of: A. Gold B. Silver c. Aluminium D. All of these |
12 |
| 740 | Question 2. What is the role of depressant in froth floatation process? TL 61 |
12 |
| 741 | At ( 1000^{circ} mathrm{C}, Delta G^{circ} ) of the reaction is: ( Z n O+C longrightarrow Z n+C O ) A. ( -v e ) B. ( +v e ) c. zero D. None of these |
12 |
| 742 | The better reducing agent at ( 7100^{circ} mathrm{C} ) is: A. ( C O ) (Ellingham diagram) B. Coke c. Both are equal D. None of these |
12 |
| 743 | Willemite is ( mathbf{A} cdot Z n_{2} S i O_{4} ) ( mathbf{B} cdot H_{2} P t C l_{6} ) ( c cdot Z n O ) D. ( Z n O F e_{2} O_{3} ) |
12 |
| 744 | The ore that can be concentrated by magnetic separation method is: A ( cdot ) bauxite ( left(A l_{2} O_{3} cdot x H_{2} Oright) ) B . pyrolusite ( left(M n O_{2}right) ) C . cuprite ( left(C u_{2} Oright) ) D. zincite ( (Z n O) ) |
12 |
| 745 | Write the correct alternatives: In the Wilfley table method, the particles of gangue are separated by ( dots dots dots ) A. Magnetic B. Froth floatation c. Hydraulic D. Gravitational |
12 |
| 746 | When aqueous solution of cupric bromide is electrolyzed the product obtained at cathode will be A. ( C u ) в. ( H_{2} ) c. ( B 4_{2} ) D. ( O_{2} ) |
12 |
| 747 | Choose the correct options – This question has multiple correct options A. The metal added to gold to harden it is iron B. The molten metal that catches fire in chlorine gas and gives off white fumes is sodium. C. The metal that forms two types of its oxide and rust in moisture is iron. The formulas of its oxides are : ( mathrm{FeO} ; mathrm{Fe}_{2} mathrm{O}_{3} ) D. The metal used in hot water systems is copper, because it is a good conductor of heat and electricity |
12 |
| 748 | In the extraction of nickel by Monds process, the metal is obtained by: A. Electrochemical reduction B. Thermal decomposition c. Chemical reduction by aluminium D. Reduction by carbon |
12 |
| 749 | The extraction of metals from their ores and then refining them for use is known as A. metallurgy B. extacting c. metal technology D. none of these |
12 |
| 750 | There are several methods for refining metals. Explain a method for refining Zirconium. | 12 |
| 751 | Which of the following pair of metals is purified by van-Arkel method? ( mathbf{A} cdot Z r ) and ( T i ) B. ( A g ) and ( A u ) c. ( N i ) and ( F e ) D. Ga and In |
12 |
| 752 | Silver metal is recovered industrially by using the chemistry shown below. Which of the following statements is/are not true? ( boldsymbol{2} boldsymbol{K}left[boldsymbol{A} boldsymbol{g}(boldsymbol{C} boldsymbol{N})_{2}right]+boldsymbol{Z} boldsymbol{n} rightarrow ) ( mathbf{4} boldsymbol{K}_{mathbf{2}}left[boldsymbol{Z} boldsymbol{n}(boldsymbol{C} boldsymbol{N})_{4}right]+mathbf{2} boldsymbol{A} boldsymbol{g} ) This question has multiple correct options A. Ag has been oxidised and Zn reduced B. Ag has been reduced and Zn oxidised c. Both ( mathrm{Ag} ) and ( mathrm{Zn} ) have been oxidised D. Both Ag and Zn have been reduced |
12 |
| 753 | The formula of calamine ore is : A ( . Z n S ) в. ( F e C O_{3} ) ( mathrm{c} cdot Z n C O_{3} ) D. ( C u_{2} S ) |
12 |
| 754 | Describe the extraction of two metals and two non-metals by electrolysis. |
12 |
| 755 | What type of resource copper is? A. Exhaustible B. Non-exhaustible C . Potential D. National |
12 |
| 756 | ( Delta G^{o} ) versus ( T ) plot in the Ellingham’s diagram slopes downward for which of the reaction? ( ^{mathbf{A}} cdot c+frac{1}{2} O_{2} rightarrow C O ) в. ( c O+frac{1}{2} O_{2} rightarrow C O_{2} ) ( mathrm{c} cdot_{2 A g+frac{1}{2}} O_{2} rightarrow A g_{2} O ) D. ( _{M g+frac{1}{2} O_{2} rightarrow M g O} ) |
12 |
| 757 | Highly electropositive metals are best produced by A. electrolytic methods B. reduction with carbon of their oxides c. straight thermal decomposition of salts D. reduction of their halides by hydrogen |
12 |
| 758 | Joul, o comes into the froth and thus separated. Q. 34 The purest form of iron is prepared by oxidising impunties in a reverberatory furnace. Which iron ore is used to line the tumace: Explain by giving reaction. |
12 |
| 759 | Generally sulphide ores are concentrated by which of the following process? A. Hand picking B. Washing with water c. Leaching D. Froth floatation |
12 |
| 760 | Oxidation states of the metal in the minerals haematite and magnetite, respectively are: A. II, Ill in haematite and III in magnetite B. II, III in haematite and II in magnetite c. Il in haematite and II, lII in magnetite D. III in haematite and II, III in magnetite |
12 |
| 761 | 2.33 How do we separate two sulphide ores by froth floatation method? Explain with an example. Ans TWO sulphide on |
12 |
| 762 | Extraction of zinc from zinc blende is achieved by: A. electrolytic reduction B. roasting followed by reduction with carbon C. roasting followed by reduction with another metal D. roasting followed by self reduction |
12 |
| 763 | Write the principles of the following methods. (i) Froth floatation method (ii) Electrolytic refining |
12 |
| 764 | . 80 What is the role of adsorption in froth floatation process used especially for concentration of sulphide ores? 10 |
12 |
| 765 | Describe the extraction of Mercury metal from its ore Cinnabar ( (boldsymbol{H} boldsymbol{g} boldsymbol{S}) ) | 12 |
| 766 | Aluminothermy used for the spot welding of large iron structures is based upon the fact that: This question has multiple correct options A. As compared to iron, aluminium has greater affinity for oxygen. B. As compared to aluminium, iron has greater affinity for oxygen. C. Reaction between aluminium and oxygen is endothermic. D. Reaction between iron oxide and aluminium is exothermic. |
12 |
| 767 | At ( 1100^{circ} mathrm{C} ), which reaction is spontaneous to a maximum extent? A. ( M g O+C rightarrow M g+C O ) B. ( Z n O+C rightarrow Z n+C O ) c. ( M g O+Z n rightarrow M g+Z n O ) D. ( Z n O+M g rightarrow M g O+Z n ) |
12 |
| 768 | Consider the following statements. I Pig iron is malleable and ductile. Il : Pig iron can be melted to produce cast iron of desired shapes. III : Wrought iron is obtained by heating pig iron with iron oxide in a furnace. Which of the statement(s) given above is/are correct? A. I only B. I and II c. ॥ and III D. III only |
12 |
| 769 | The minerals are the compounds of metal with sulphur. |
12 |
| 770 | Blister copper obtained during extraction from cuprous oxide is called so because: A. it has blister like eruptions due to evolution of gas B. it has a shining surface like blister c. it is the most impure form of copper D. its surface is uneven due to different thickness at different place |
12 |
| 771 | In chromite ore, the oxidation number of iron, and chromium are respectively. ( A cdot+3,+2 ) ( B cdot+3,+6 ) ( c cdot+2,+6 ) ( D cdot+2,+3 ) |
12 |
| 772 | In froth floatation process for the purification of ores, the particles of ore float because: A. their surface is not easily wetted by water B. they are light c. they are insoluble D. they bear electrostatic charge |
12 |
| 773 | Give an example of zone refining of metals. |
12 |
| 774 | Which of the following reactions taking place in the blast furnace during extraction of iron is endothermic? A ( cdot C a C O_{3} rightarrow C a O+C O_{2} ) в. ( 2 C+O_{2} rightarrow 2 C O ) c. ( C+O_{2} rightarrow C O_{2} ) D. ( F e_{2} O_{3}+3 C O rightarrow 2 F e+3 C O_{2} ) |
12 |
| 775 | The main source of lead is PbS. It is converted to Pb by:- (i) ( P b S frac{a i r}{Delta} P b O+S O_{2} frac{C}{Delta} P b+C O_{2} ) (ii) ( P b S frac{a i r}{Delta} P b O+P b S stackrel{Delta}{longrightarrow} P b+S O_{2} ) Self reduction process is: ( A ) B. i c. both D. none |
12 |
| 776 | The constituents of the electrolyte for the extraction of aluminium is A. 40 parts cryolite +40 parts fluorspar +20 parts pure ( A l_{2} O_{3} ) B. 60 parts cryolite +30 parts fluorspar +10 parts pure ( A l_{2} O_{3} ) C. 30 parts cryolite +30 parts fluorspar +40 parts pure ( A l_{2} O_{3} ) D. 60 parts cryolite +20 parts fluorspar +20 parts pure ( A l_{2} O_{3} ) |
12 |
| 777 | Al is obtained by the electrolysis of fused mixture of ( A l_{2} O_{3} ) and ( N a_{2} A l F_{6} . ) If true enter 1 else 0 |
12 |
| 778 | Name two metals which can be refined by Van Arkel Method. |
12 |
| 779 | The principle behind froth floatation is: A. preferential wetting of ore and gangue particles. B. difference is specific gravity of ore and gangue particles. C. magnetic properties of ore and gangue. D. electrical properties of gangue particles. |
12 |
| 780 | Liquation process is used for the concentration of which ore? A. Stibinite B. Tinstone c. limestone D. Haematite |
12 |
| 781 | (a) Explain the following. (i) Roasting (ii) Calcination. (b) What are amphoteric oxides? Write the name of such one oxide. (c) By which two metals is brass alloy formed? |
12 |
| 782 | Which of the following statements is incorrect? A. Calamine and Siderite are carbonates. B. Argentite and Cuprite are oxides. C. Zinc blende and Pyrites are sulphides. D. Malachite and Azurite are ores of copper. |
12 |
| 783 | Chemical leaching is useful in the concentration of: A. bauxite B. copper pyrities c. cassiterite D. None of the above |
12 |
| 784 | Explain froth flotation process of copper pyrites. | 12 |
| 785 | Identify the principle behind the concentration of bauxite ore: A. magnetic property of impurities in white bauxite B. low specific gravity of ( A l_{2} O_{3} ) C . amphoteric nature of ( A l_{2} O_{3} ) D. high melting point of ( A l_{2} O_{3} ) |
12 |
| 786 | Sodium cyanide is used in the: A. cleaning of silver B. creation of fires C . purification of acids D. extraction of gold |
12 |
| 787 | Match the extraction process with the metals. |
12 |
| 788 | The following equation represents a method of purification of nickel by: ( N i+4 C O(text {impure}) stackrel{320 K}{rightarrow} N i(C O)_{4} stackrel{420 L}{longrightarrow} ) A. Cupellation B. Mond’s process c. van Arkel method D. zone refining |
12 |
| 789 | Metals that are refined by liquation are: This question has multiple correct options A. si B. Pb ( c cdot s n ) D. Bi |
12 |
| 790 | A solution of ( N a_{2} S O_{4} ) in water is electrolysed using inert electrodes. The products at the cathode and anode respectively, are: A. ( O_{2}, H_{2} ) в. ( O_{2}, ) Na c. ( H_{2}, O_{2} ) D. ( O_{2}, S O_{2} ) |
12 |
| 791 | 0.21 Which of the following reactions occur during calcination? (a) CaCO3 CaO + CO2 (b) 2Fes, +0, Fe,0,+ 450, (c) AIO, XH,0- A1,0 + xH,0 (d) ZnS+0,- ZnO + So, |
12 |
| 792 | Generally which ores are concentrated by froth floatation method? Describe this method. |
12 |
| 793 | The following equation represents a method of purification of nickel by: ( N i(text {impure})+4 C O stackrel{320 K}{longrightarrow} ) ( N i(C O)_{4} stackrel{420 K}{longrightarrow} N i(text {pure})+4 C O ) A. Cupellation B. Mond’s process c. van Arkel method D. zone refining |
12 |
| 794 | Assertion Statement-I: In the extraction of Ag the ( operatorname{complex} N aleft[A g(C N)_{2}right] ) is reacted with Zn. Reason Statement- – II : Zn is transition metal according to electronic theory. Read the above assertion and reason |
12 |
| 795 | In bessemer converter, oxides of manganese and silicon are removed as: A. manganese silicate B. silica c. magnesium oxide D. none of these |
12 |
| 796 | What will happen during roasting? A. The sulphide ores are converted into oxides B. The oxide ores are converted into sulphides C. The sulphide ores are converted into carbonates D. The oxide ores are converted into carbonates. |
12 |
| 797 | During concentration of ( _{–}-_{-}- ) ores by froth floatation process potassium ethy xanthate is added. A. sulphide B. carbonate c. halide D. amide |
12 |
| 798 | Which method of purification is represented by the following equation? ( boldsymbol{T} boldsymbol{i}(boldsymbol{s})+boldsymbol{2} boldsymbol{I}_{2}(boldsymbol{g}) stackrel{boldsymbol{5} mathbf{2} 3 boldsymbol{k}}{longrightarrow} boldsymbol{T} boldsymbol{i} boldsymbol{l}_{4}(boldsymbol{g}) frac{mathbf{1 7 0 0} boldsymbol{k}}{boldsymbol{}} ) ( boldsymbol{T} boldsymbol{i}(boldsymbol{s})+boldsymbol{2} boldsymbol{I}_{2}(boldsymbol{g}) ) A. zone refining B. Cupellation c. Poling D. Van Arkel |
12 |
| 799 | According to Ellingham diagram, the oxidation reaction of carbon to carbon monoxide may be used to reduce which one of the following oxides at the lowest temperature? A. ( A l_{2} O_{3} ) в. ( C u_{2} O ) с. ( M g O ) D. ( Z n O ) |
12 |
| 800 | Name a metal refined by Van Arkel method. |
12 |
| 801 | Which of the following metal’s oxide can be reduced by Fe as reducing agent at temperature ( boldsymbol{T}_{mathbf{1}} ) ? ( A cdot P b ) B. ( mathrm{ca} ) c. ( mathrm{Mg} ) D. None of these |
12 |
| 802 | A solution is a homogeneous mixture of two or more substances. Which of the following is a solution? A . Milk B. Smoke c. Brass D. Face Cream |
12 |
| 803 | Most abundant metal in the earth’s crust is |
12 |
| 804 | Which of the following pairs of metals is purified by van Arkel method? A. Ga and In B. Zr and Ti c. ( A g ) and ( A u ) D. Ni and Fe |
12 |
| 805 | The product formed at anode and cathode, when dilute ( boldsymbol{H}_{2} boldsymbol{S} boldsymbol{O}_{4} ) is electrolyzed are A ( . S O_{2}, H ) в. ( S O_{3}, H_{2} ) c. ( H_{2} S_{2} O_{8}, H_{2} ) D. ( O_{2}, H_{2} ) |
12 |
| 806 | The combined state of metals are called: A. Mineral B. Gangue c. Flux D. Native form |
12 |
| 807 | 26. Assertion : Lead, Tin and bismuth are purified by liquation method, Reason: Lead, Tin and bismuth have low m.p. as compared to impurities. |
12 |
| 808 | Sulphides ores are converted to oxides before reduction. This is explained on the basis of which of the following? A. Sulphides cannot be reduced easily while oxides can be reduced easily. B. Sulphides decompose on reduction hence they are fixed converted to oxides. C. Sulphide ores have higher melting points than oxides. D. Oxides are more stable than sulphides hence easy to reduce. |
12 |
| 809 | ( Delta G^{circ} ) vs ( T ) plot in Ellingham diagram slopes downward for the reaction: ( ^{mathrm{A}} cdot_{M g}+frac{1}{2} O_{2} rightarrow M g O ) в. ( _{2 A g}+frac{1}{2} O_{2} longrightarrow A g_{2} O ) ( ^{mathrm{c}} cdot c+frac{1}{2} O_{2} rightarrow C O ) ( ^{mathrm{D}} cdot_{C O}+frac{1}{2} O_{2} rightarrow C O_{2} ) |
12 |
| 810 | Sphalerite is a mineral that is the chief ore of zinc. A . True B. False |
12 |
| 811 | Sequence the following steps involved generally in the extraction of a metal in pure form from its ore (a) The metal obtained from its oxide require further purification for end use (b) The ore should be converted to its oxide form. (c) The ore is beneficial to us if it is handpicked then metal crushed and ground, and later subjected to pulverization as per the requirement (d) The ore in the form of oxide is required to be reduced. (e) Dressed ore is required for it to be concentrated. A ( cdot operatorname{ecbd} ) B. cebda ( c cdot operatorname{cob} a d ) D. ced b a |
12 |
| 812 | The conversion of aluminium hydroxide to pure alumina is carried out by: A. addition of ( A l(O H)_{3} ) crystals B. thermal decomposition c. precipitation D. none of these |
12 |
| 813 | A compound added to lower the fusion temperature of the electrolytic bath in the extraction of Al is A. cryolite and fluorspar B. Bauxite c. Iron and fluorspar D. none of these |
12 |
| 814 | The process used for purification of ( A l_{2} O_{3} cdot 2 H_{2} O ) is: A . Magnetic separation B. Froth flotation c. Leaching D. Liquation |
12 |
| 815 | ( boldsymbol{A} boldsymbol{g}_{2} boldsymbol{S}+boldsymbol{N} boldsymbol{a} boldsymbol{C}+boldsymbol{Z} boldsymbol{n} longrightarrow boldsymbol{A} boldsymbol{g}^{+} ) This method of extraction of Ag by the complex formation and then its displacement is called: A. Parke’s method B. Mac Arthur-Forest method c. Serpek method D. Hall’s method |
12 |
| 816 | What is electrolysis? A. Decomposition of substance by passing electricity B. Decomposition of substance by heating C. Decomposition of substance by redox reaction D. Addition of hydrogen |
12 |
| 817 | ASSERTION: In the extraction of Ag, complex ( mathrm{Na}left[mathrm{Ag}(mathrm{CN})_{2}right] ) is reacted with Zn. REASON: Zn is a d-block transition |
12 |
| 818 | Give both chemical equations of leaching of silver in silver metallurgy by using sodium cyanide? | 12 |
| 819 | Use the relationship ( Delta G^{circ}=-n F E_{text {cell }}^{circ} ) to estimate the minimum voltage required to electrolyse ( A l_{2} O_{3} ) in the Hall-Heroult process. ( Delta G_{f}^{circ}left(A l_{2} O_{3}right)=-1520 k J m o l^{-1} ) ( Delta G_{f}^{circ}left(C O_{2}right)=-394 k J m o l^{-1} ) The oxidation of the graphite anode to ( C O_{2} ) permits the electrolysis to occur at a lower voltage than if the electrolysis reactions were: ( A l_{2} O_{3} rightarrow 2 A l+3 O_{2} ) What is the approximate value of low voltage? ( A cdot 2 V ) B. 3 V ( c cdot 4 v ) D. ( 5 v ) |
12 |
| 820 | 28. How many of the given elements are extracted by electroluti refining? Pb, Hg, Ag, Zn, Zr and Ge |
12 |
| 821 | If 0.5 mole of silver salt is taken and the weight of residue obtained is 216 g. ( (mathrm{Ag} ) ( =108 mathrm{g} / mathrm{mol} ) ).Than which the following is correct? [ begin{array}{c} C_{2} H_{3} \ (C quad H-C O O H)_{3}+ \ C_{2} H_{3} \ A g N O_{3}(E x c e s s) longrightarrow S i l v e r s a l t longrightarrow \ A g(m e t a l) end{array} ] ( mathbf{A} cdot n=4 ) B ( . n=2 ) C. M.wt. of silver salt is 718 g/mol D. M.wt. of silver salt is ( 388 mathrm{g} / mathrm{mol} ) |
12 |
| 822 | The oil used as frothing agent in froth floatation process is? | 12 |
| 823 | ( boldsymbol{C u} boldsymbol{C O}_{3} cdot boldsymbol{C u}(boldsymbol{O H})_{2} ) is also known as Malachite (green). State True or False. A. True B. False c. Cannot be determined D. None of the above |
12 |
| 824 | Usually refractory metals are used in construction of furances because: This question has multiple correct options A. they are chemically inert B. their melting point is high C. they can withstand high temperature D. none of the above |
12 |
| 825 | The zone refining process of metals is based on the principle of : A. excess noble character of the liquid metal than that of impurity B. lower melting point of the impurity than that of pure metal c. greater solubility of impure metal than that of impurity D. greater solubility of the impurities in the molten state than in the solid |
12 |
| 826 | Which of the following is not correctly matched with respect to the processes involved in the extractive metallurgy of the respective metal? ( mathbf{A} cdot A l_{2} O_{3} cdot 2 H_{2} O rightarrow A l: ) Leaching, precipitation calcination and electrolytic reduction (molten state) B. ( A g_{2} S rightarrow A g ) : Leaching and displacement method C ( . P b S rightarrow P b ) : Froth flotation process, roasting and self reduction D. ( K C l . M g C l_{2} .6 H_{2} O rightarrow M g ) : Dehydration by simple heating and electrolytic reduction in aqueous phase |
12 |
| 827 | How much approx aluminium in g can be produced by a current of 94 A flowing through a Hall-Heroult cell for 1.00 h? (If the answer is ( left.X, text { then write } frac{X}{8}right) ) |
12 |
| 828 | Carbon monoxide is more effective reducing agent than carbon below 983 K but above this temperature the reverse is true. If true enter 1 else 0 A |
12 |
| 829 | Name the method used for the refining of Nickel metal. |
12 |
| 830 | Write chemical reactions taking place in the extraction of zinc from zinc blende. |
12 |
| 831 | Which of the following are the ores of zinc? A. Calamine and zinc blend B. Zinc blend and cerussite c. calomine and siderite D. zinc blend and carnallite |
12 |
| 832 | Which ore does not contain carbonate? A. Calamine B. ciderite c. Malachite D. zincite |
12 |
| 833 | ( (boldsymbol{A}+boldsymbol{A} boldsymbol{g})+boldsymbol{Z} boldsymbol{n} longrightarrow(boldsymbol{A}+boldsymbol{A} boldsymbol{g}+ ) ( Z n) frac{operatorname{cooling}}{y-operatorname{layer}} frac{x-operatorname{layer}}{y-ln } ) x layer – solid alloy y layer – molten metal Molten metal is purified by: A. Hall-Heroult process B. Hoop method c. Baeyer’s process D. Parkes process |
12 |
| 834 | Ag can be obtained from purified Zn-Ag alloy by : A. distillation B. poling c. liquation D. reduction |
12 |
| 835 | Semiconductor materials like ( S i ) and ( G e ) are usually purified by: A. distillation B. zone refining c. liquation D. electrolytic refining |
12 |
| 836 | Deleuceu by CU UHy below PUIHIL A. Q. 13 For the reduction of FeO at the temperature corresponding to point D, which of the following statements is correct? (a) AG value for the overall reduction reaction with carbon monoxide is zero. (b) AG value for the overall reduction reaction with a mixture of 1 mol carbon and 1 mol oxygen is positive. (C) AG value for the overall reduction reaction with a mixture of 2 mol carbon and 1 mol oxygen will be positive. (d) AG value for the overall reduction reaction with carbon monoxide is negative. Ans (a) At point AG cunt for formation of 2.09 |
12 |
| 837 | Assertion Alkali metals cannot be prepared by electrolysis of their chlorides in aqueous solution. Reason Reduction potentials of alkali metal cations is much lower than that of ( boldsymbol{H}^{+} ) 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 |
| 838 | Identify the reaction that does not take place in a blast furnace. A. ( C a C O_{3} rightarrow C a O+C O_{2} ) в. ( C a O+S i O_{2} rightarrow C a S i O_{3} ) ( mathbf{c} cdot 2 F e_{2} O_{3}+3 C rightarrow 4 F e+3 C O_{2} ) D. ( C O_{2}+C rightarrow 2 C O ) |
12 |
| 839 | Silver is displaced when zinc is added to aqueous sodium argentocyanide. This method of extracting silver is an example of : A. leaching B. hydrometallurgy c. pyrometallurgy D. liquation |
12 |
| 840 | bago Tbon Q. 12 Below point ‘A’ FeO can …………. (a) be reduced by carbon monoxide only. (b) be reduced by both carbon monoxide and carbon. (c) be reduced by carbon only. (d) not be reduced by both carbon and carbon monoxide. tre |
12 |
| 841 | Pick up the correct statement(s): This question has multiple correct options A. All minerals are ores B. All minerals cannot be ore C. All ores are minerals D. The mineral from which metals can be extracted profitably are called ores |
12 |
| 842 | Liquation method is used to refine which of the following crude metal? A . Silver B. Leadd C. Mercury D. copper |
12 |
| 843 | In Down’s process for the extraction of sodium, the melting point of ( N a C l ) is lowered from ( 803^{0} C ) to ( 600^{0} C ) Choose the correct statement(s) regarding this. a) It is done in order to avoid vapourisation of metallic sodium. b) It is done in order to avoid corrosive action of sodium and chlorine on the vessel at the high temperature. c) It is done by mixing sufficient amounts of ( boldsymbol{C a} boldsymbol{C l}_{2} ) A. Only a is correct B. Only a and b are correct c. Only a and c are correct D. All a, b and c are correct |
12 |
| 844 | Ni is metal but dissolved in ( C O ) gas due to formation of ( A . A ) decomposes into metal. (a)What is ( A ) ? (b) ( A ) is formed at what temperature (c) ( A ) decomposes into metal at what temperature A ( cdot(text { a }) N i(C O)_{4} ;(b) 28^{0} Cleft(text { c) } 230^{0} Cright. ) B . (a) ( N i(C O)_{4} ;(b) 48^{0} C ) (с) ( 330^{0} C ) C ( cdot ) (a) ( N i(C O)_{2} ;(b) 14^{0} C ) (c) ( 230^{0} C ) D. (a) ( N ileft(C O_{2} ; text { (b) } 56^{circ} C text { (с) } 125^{circ} Cright. ) |
12 |
| 845 | Give the balanced equations for the conversion of argentite ( left(boldsymbol{A} boldsymbol{g}_{2} boldsymbol{S}right) ) to metallic silver. |
12 |
| 846 | Predict whether the following statement is true or false. The most abundant metal in the earth’s |
12 |
| 847 | Out of the following metals, that can be obtained by electrolysis of the aqueous solution of their salts is/are: This question has multiple correct options ( A cdot A g ) B. Au c. ( c u ) D. Mg |
12 |
| 848 | The following question is relevant to the extraction of Aluminium: Along with cryolite and alumina, another substance is added to the electrolyte mixture. the substance is A. Fluorspar B. Mica c. Nacı D. None of these |
12 |
| 849 | Silver and gold are purified with: A . nitric acid в. НС l c. acetic acid D. sulphuric acid |
12 |
| 850 | (a) Roasting and calcination are the two processes to reduce the metal oxides to the respective metals. (b) Magnesium is extracted from its ore by electrolytic reduction process. (c) Cryolite is used in metallurgy of aluminium in order to increase the fusibility and conductivity (d) I Hall’s process bauxite is leached with the help of ( N a_{2} C O_{3} ) Which of the following options regarding the above statements is correct? ( A cdot a, b ) and ( c ) B. b, c and d ( c cdot c ) and ( d ) |
12 |
| 851 | Question 11. What should be the considerations during the extraction of metals by electrochemical method? |
12 |
| 852 | Chemical leaching is not useful in the concentration of: This question has multiple correct options A. copper pyrite B. bauxite c. galena D. cassiterite |
12 |
| 853 | Which of the following methods is based on the principle of the difference in the wetting properties of the ore and gangue particles with water and oil? A. Magnetic separation B. Froth floatation process c. Hydraulic washing D. None of these |
12 |
| 854 | Chloroform on reduction with zinc dust and water gives A. Methyl chloride B. Dichloro methane c. chloro methane D. Methane |
12 |
| 855 | What is the role of graphite rod in the electrometallurgy of aluminium? | 12 |
| 856 | Sulphur is extracted by Frasch process. If true enter 1 else 0 | 12 |
| 857 | Write a short note on gangue and anode mud. |
12 |
| 858 | Consider the below shown reaction. ( boldsymbol{A} boldsymbol{g}_{2} boldsymbol{S}+boldsymbol{N} boldsymbol{a} boldsymbol{C} boldsymbol{N} longrightarrow(boldsymbol{A}) ) ( (A)+Z n longrightarrow(B) ) If ( (B) ) is a metal, then ( (A) ) and ( (B) ) are, respectively: A ( cdot N a_{2}left[Z n(C N)_{4}right] ) and ( Z n ) В. ( operatorname{Na}left[A g(C N)_{2}right] ) and ( A g ) c. ( N a_{2}left[A g(C N)_{4}right] ) and ( A g ) D. ( N a_{3}left[A g(C N)_{4}right] ) and ( A g ) |
12 |
| 859 | Carbon reduction process is not commercially applicable for which of the following set of oxides to extract the respective metal? (I) ( Z n O ) ( (|) boldsymbol{F} boldsymbol{e}_{2} boldsymbol{O}_{3} ) ( (| I) A l_{2} O_{3}(I V) ) ( boldsymbol{S} boldsymbol{n} boldsymbol{O}_{2}(vee) boldsymbol{M} boldsymbol{g} boldsymbol{O} ) A. ( Z n O, F e_{2} O_{3}, S n O_{2} ) в. ( Z n O, S n O_{2}, M g O ) ( mathrm{c} cdot mathrm{Mg} mathrm{O}, mathrm{Al}_{2} mathrm{O}_{3} ) D. ( M g O, S n O_{2}, A l_{2} O_{3} ) |
12 |
| 860 | Choose the correct option of temperature at which carbon reduces Fe0 to iron and produces CO. A. Below temperature at point B. Approximately at the temperature corresponding to point c. Above temperature at point A but below temperature at point D. Above temperature at point |
12 |
| 861 | Rusting of an iron nail is reaction. A. Combination B. displacement c. decomposition D. double displacement |
12 |
| 862 | The method of extraction of Ag by cyano complex formation followed by metal displacement is called A. Parke’s method B. McArthur-Forest method c. serpeck method D. Hall’s method |
12 |
| 863 | Question 5. Out of C and CO, which is a better reducing agent at 673 KP Consider Ellingham diagram for the value of AG of C and CO at different temperatures. On the basis of AG, give answer. |
12 |
| 864 | Which of the following metal is purified by using Monds process? A . ( N i ) в. ( Z r ) c. ( T i ) D. ( C u ) |
12 |
| 865 | Identify the substance underlined, in each of the following cases: The electrolyte used for electroplating an article with silver. |
12 |
| 866 | The metal whose oxide, which is amphoteric, is reduced to metal by carbon reduction ( (boldsymbol{F} boldsymbol{e} / boldsymbol{M} boldsymbol{g} / boldsymbol{P b} / boldsymbol{A l}) ) |
12 |
| 867 | A metallic oxide which on heating gives a metal and oxygen is: ( A cdot S O_{2} ) в. ( H g O ) c. ( N a_{2} O ) D. ( F e_{2} O_{3} . x H_{2} O ) |
12 |
| 868 | Assertion Carbonate and hydroxide ores are concectrated by forth floatation process. Reason In forth floatation process, mineral oil is used due to it preferentitally wets the gangue particles. 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 |
| 869 | Purification of alumina takes place by A. Bosch process B. Hall’s process c. Hoope’s process D. Quartation process |
12 |
| 870 | The reaction ( boldsymbol{C r}_{2} boldsymbol{O}_{3}+boldsymbol{2} boldsymbol{A} boldsymbol{l} rightarrow boldsymbol{A l}_{2} boldsymbol{O}_{3}+ ) ( 2 C rleft(triangle G^{0}=-421 k Jright) ) is thermodynamically feasible due to -ve value of ( triangle G . ) Why does this reaction not take place at room temperature? A. Certain amount of activation energy is essential for thermodynamically feasible reactions also. B. Due to high melting point of chromium oxide the reaction does not take place c. overall value of ( triangle G ) for the net reaction becomes positive D. Molecules of ( C r_{2} O_{3} ) and ( A ) l are not oriented properly |
12 |
| 871 | State the role of silica in the metallurgy of copper. |
12 |
| 872 | Assertion In the metallurgy of iron, limestone is added to the ore Reason In the metallurgy of iron, limestone ( left(mathrm{CaCO}_{3}right) ) acts as a flux and forms calcium silicate ( mathrm{CaSiO}_{3}(mathrm{slag}) ) Read the above assertion and reason and choose the correct option regarding ¡t. 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 |
| 873 | Which one of the following ores is known as Malachite? ( mathbf{A} cdot C u_{2} O ) в. ( C u_{2} S ) c. ( C u F e S_{2} ) D. ( C u(O H)_{2} . C u C O_{3} ) |
12 |
| 874 | Q. 38 Which method is used for refining Zr and Ti? Explain with equation. | 12 |
| 875 | ( boldsymbol{A} boldsymbol{g}_{2} boldsymbol{S}+boldsymbol{N} boldsymbol{a} boldsymbol{C} boldsymbol{N} rightarrow boldsymbol{A} ) ( boldsymbol{A}+boldsymbol{Z} boldsymbol{n} rightarrow boldsymbol{B} ) B is a metal. Hence ( A ) and ( B ) : ( mathbf{A} cdot operatorname{Na}_{2}left[operatorname{Zn}(C N)_{4}right], Z n ) в. ( operatorname{Na}left[operatorname{Ag}(C N)_{2}right] ) ], ( A g ) c. ( operatorname{Na}left[operatorname{Ag}(C N)_{4}right] ) ], ( A g ) D・ ( left.operatorname{Na}_{3}left[operatorname{Ag}(C N)_{4}right)right], A g ) |
12 |
| 876 | The role of coke in the electrolytic reduction of alumina is to A. provide heat for melting of alumina B. prevent loss of heat c. prevent burning of carbon rods D. reduce alumina to metal |
12 |
| 877 | 46 Match the items of Column I with the items of Column II and assign the correct code. Column 1 A B C D. Coloured bands Impure metal to volatile complex Purification of Ge and si Purification of mercury Column 11 1. Zone refining 2. Fractional distillation 3. Mond’s process 4 Chromatography 5. Ulquation Codes A B (a) 1 2 (c) 3 4 C 4 2 D 5 1 A (b) 4 (d) 5 B 3 4 C 1 3 D 2 2 |
12 |
| 878 | Which of the following ores are concentrated by Froth Flotation. A. Oxide ores B. Chloride ores c. sulphide ores D. Nitride ores |
12 |
| 879 | Ag is precipitated when ( Z n ) is added to ( left[boldsymbol{A} boldsymbol{g}(boldsymbol{C} boldsymbol{N})_{2}right]^{-} ) If ( 2left[A g(C N)_{2}right]^{-}+Z n rightarrow ) ( left[Z n(C N)_{4}right]^{2-}+2 A g ) is the reaction enter 1 else 0. |
12 |
| 880 | Carbon cannot be used to reduce : A. ( Z n O ) в. ( operatorname{Sn} O_{2} ) ( mathrm{c} cdot F e_{2} O_{3} ) D. ( A l_{2} O_{3} ) |
12 |
| 881 | Which of the following are true for electrolytic extraction of aluminium? This question has multiple correct options A. Cathode material contains graphite B. Anode material contains graphite C. Cathode reacts away forming ( C O_{2} ) D. Anode reacts away forming ( C O_{2} ) |
12 |
| 882 | Metals which can be obtained by carbon reduction of their oxides are This question has multiple correct options A. cu B. Fe c. ( A l ) D. Pb |
12 |
| 883 | For the reduction of ( F e O ) with ( C ) at the temperature corresponding to ( (D) ) which of the following statements is correct? A. Carbon reduces ( F e O ) below the temperature at point (D) B. ( triangle G^{0} ) value for overall reduction with ( C O ) is zer ( mathrm{c} . triangle G^{0} ) value for the reaction at point (D) is positive D. Below point (D), for the metal exists in molten state |
12 |
| 884 | A metal oxide ( M O_{(s)} ) can be reduced by carbon or carbon monoxide successfully when the line in Ellingham diagram for reaction (i): A. lies above the line for one of the reactions (ii) to (iv) B. intersects the line for one of the reactions (ii) to (iv) (ii) to (iv) c. lies below the line for one of the reactions D. may lie above or below the line for one of the reactions (ii) to (iv) depending upon the temperature |
12 |
| 885 | Complexes formed in the following methods are: (1) Mond’s process for purification of nicke (II)Removal of lead poisoning from the body (III) Cyanide process for extraction of silver (IV) Froth floatation process for separation of ( Z n S ) from galena are by using depressant ( begin{array}{llll}text { A } cdot operatorname{Ni}(C O)_{4} & {[P b(E D T A)]^{2-}} & {left[A g(C N)_{2}right]} & {left[Z n(C N)_{2}right]}end{array} ) B. ( N i(C O)_{4} quad[P b(E D T A)]^{2-} quadleft[A g(C N)_{2}right]^{-} ) [ left[Z n(C N)_{4}right]^{2} ] ( begin{array}{lll}text { C. } N i(C O)_{6} & {[P b(E D T A)]^{4-}} & {left[A g(C N)_{2}right]^{-}left[Z n(C N)_{6}right]^{4}}end{array} ) ( D ) ( N i(C O)_{4} ) ( [P b(E D T A)]^{2-} ) ( left[A g(C N)_{4}right]^{3-} ) ( left[Z n(C N)_{4}right] ) |
12 |
| 886 | 2. Which of the following reactions is an example of autoreduction? (a) Fe, 04 + 4CO 3Fe + 4CO2 (b) Cuz O+ C 2Cu + CO (c) Cu2+ (aq) + Fe(s) Cu(s) + Fe2+ (aq) (d) Cu, +cu, s — 3Cu+SO, |
12 |
| 887 | 1 correctly describes the process of electrolytic refining? ( A ) ( B ) ( c ) None of the above |
12 |
| 888 | Which of the following process is not involved in the extraction of Fe? A. Gravity separation B. Leaching c. Roasting D. Carbon reduction |
12 |
| 889 | In the Castner process for the extraction of sodium, the anode is made of: A. copper B. iron c. sodium D. nickel |
12 |
| 890 | Which of the following is not correct? A. ( A l ) reacts with ( N a O H ) and liberate ( H_{2} ) B. ( A l C l_{3} ) is a lewis acid C. ( A l ) is used in the manufacture of electrical cables D. ( N a O H ) is used during Hall’s process of purification of bauxite |
12 |
| 891 | Sulfide ores are common for the metals: ( A cdot A g, ) Cu and ( P b ) B. Ag, Cu and sn c. ( A g, ) Mg and Pb D. Al, Cu and Pb |
12 |
| 892 | Which of the following is the ore of ( C u ? ) A. ciderite B. Magnetite c. Calamine D. Malachite |
12 |
| 893 | Assertion Cryolite is used in electrolytic extraction of ( A l ) from alumina. Reason It dissolves alumina. 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 and Reason is correct |
12 |
| 894 | The reduction of an oxide by aluminium is called: A. Kroll’s process B. Van Arkel process c. Ellingham process D. Goldschmidt’s aluminothermite process |
12 |
| 895 | From the Ellingham graph between Gibb’s energy and temperature, out of ( C ) and ( C O ) which is a better reducing agent for ( Z n O ? ) A. Carbon в. ( C O ) c. Both of these D. None of these |
12 |
| 896 | Which process of purification is represented by the following scheme? ( underset{text { impure }}{boldsymbol{T i}}+mathbf{2 I}_{mathbf{2}} stackrel{mathbf{2 5 0}^{circ} boldsymbol{C}}{boldsymbol{pi} boldsymbol{i} boldsymbol{I}_{4}} frac{mathbf{1 4 0 0}^{boldsymbol{o}} boldsymbol{C}}{boldsymbol{p} boldsymbol{p} boldsymbol{i}}+ ) ( 2 I_{2} ) A. Cupellation B. Electrolytic refining c. zone refining D. Van-Arkel process |
12 |
| 897 | Sulphide ores of metals are usually concentrated by froth floatation process. Which one of the following sulphide ores offers an exception and is concentrated by chemical leaching? A. Galena B. Copper pyritee c. sphalerite D. Argentite |
12 |
| 898 | Which metallurgy involves leaching? A . ( A u ) в. ( A g ) c. Both (a) and (b) D. None of these |
12 |
| 899 | In the commercial electrochemical process for aluminium extraction, the electrolyte used is: A ( cdot A l(O H)_{3} ) in ( N a O H ) solution B. An aqueous solution of ( A l_{2}left(S O_{4}right)_{3} ) c. A molten mixture of ( A l_{2} O_{3}, N a_{3} A l F_{6} & C a F_{2} ) D. A molten mixture of ( A l O(O H) ) and ( A l(O H) ) |
12 |
| 900 | The electrolyte used in electrolytic refining of impure aluminium is ( mathbf{A} cdot A I_{2} O_{3}+C a F_{2} ) B. ( N a_{3} A l F_{6}+C a F_{2} ) ( mathbf{c} cdot A l_{2} O_{3}, N a_{3} A l F_{6} a n d C a F_{2} ) D. Any aluminium salt is molten state |
12 |
| 901 | Give an example of a metal purified by Mond process. |
12 |
| 902 | Which one of the following mineral is obtained form ocean water? A. Aluminium B. Sulphur c. Magnesium D. Iron |
12 |
| 903 | From the Ellingham graphs on carbon, which of the following statements is false? A ( cdot C O_{2} ) is more stable than ( C O ) at less than 983 k B. ( C O ) reduces ( F e_{2} O_{3} ) to ( F e ) at less than 983 k c. ( C O ) is less stable than ( C O_{2} ) at more than 983 k D. ( C O ) reduces ( F e_{2} O_{3} ) to ( F e ) in the reduction zone of Blast furnace |
12 |
| 904 | ASSERTION: In froth floatation process, sodium ethyl xanthate is used as a collector. REASON: Sulphide ores are water soluble. |
12 |
| 905 | The furnace which gives the highest temperature is: A. Blast furnace B. Reverberatory furnace c. Electrical furnace D. Muffle furnace |
12 |
| 906 | Ellingham diagram represents the change in: A. G with temperature B. ( H ) with temperature c. ( G ) with pressure D. ( G-T S ) with temperature |
12 |
| 907 | Froth floatation process for the concentration of sulphide ores is an illustration of the practical application of: A. adsorption B. absorption c. sedimentation D. coagulation |
12 |
| 908 | Which of the following reaction is a part of Hall’s process? ( mathbf{A} cdot A l_{2} O_{3}+2 N a O H rightarrow 2 N a A l O_{2}+H_{2} O ) B ( cdot F e_{2} O_{3}+2 A l rightarrow 2 F e+A l_{2} O_{3} ) ( mathbf{c} cdot A l N+3 H_{2} O rightarrow A l(O H)_{3}+N H_{3} ) D. ( A l_{2} O_{3} .2 H_{2} O+2 N a_{2} C O_{3} rightarrow 2 N a A l O_{2}+C O_{2}+2 H_{2} O ) |
12 |
| 909 | In the refining of iron, phosphorous separates as: ( mathbf{A} cdot operatorname{slag} C a_{3}left(P O_{4}right) ) B. volatile, ( P_{2} O_{5} ) c. slag, ( F e P O_{4} ) D. ( C a_{3} P_{2} ) |
12 |
| 910 | Match the column I with column II and mark the appropriate choice. Column I |
12 |
| 911 | Select the correct statement(s). This question has multiple correct options A. When the lead-silver alloy is rich in silver, lead is removed by the cupellation process. B. When the lead-silver alloy is rich in lead, silver is removed by Parke’s or Pattinson’s process C. Zinc forms an alloy with lead from which lead is separated. D. zinc forms an alloy with silver from which zinc is separated by distillation. |
12 |
| 912 | The substance used to reduce iron ore to iron in the lower part of the blast furnace is: A. coke B. charcoal c. carbon monoxide D. carbon black |
12 |
| 913 | Which is not a mineral of aluminium? A. Anhydrite B. Bauxite c. corundum D. Diaspore E. Answer Required… |
12 |
| 914 | How is silver extracted from argentite? | 12 |
| 915 | Most abundant metal in earth crust is ( A cdot A ) B. c. ( mathrm{Fe} ) ( D cdot s i ) |
12 |
| 916 | The mass of carbon anode consumed (giving the only carbon dioxide) in the production of ( 270 k g ) of aluminium metal from bauxite by the Hall process is: [atomic mass ( boldsymbol{A l}=mathbf{2 7}] ) A. ( 180 mathrm{kg} ) в. ( 270 mathrm{kg} ) c. ( 540 mathrm{kg} ) D. ( 90 mathrm{kg} ) |
12 |
| 917 | Zinc is used for the recovery of Ag from the complex ( left[A g(C N)_{2}right]- ) while copper is not used because Zn is powerful reducing agent than ( mathrm{Cu} ) If true enter 1,else enter 0. |
12 |
| 918 | Ellingham diagram represents change of: A. ( Delta G ) with temperature B. ( Delta H ) with temperature c. ( Delta G ) with pressure D. ( (Delta G-T Delta S) ) with temperature |
12 |
| 919 | Name the process usually employed for the purification of nickel? | 12 |
| 920 | What happens when copper matte is charged into silica lined converter and hot air blast is blown? |
12 |
| 921 | ( Z r I_{4} ) converted to ( Z r ) by the process 1. Monds 2. van Arkel 3. Hall 4. Kroll |
12 |
| 922 | 19. The role of calcination in metallurgical operations is (a) to remove moisture (b) to decompose carbonate (c) to make oxporous (d) to achieve all the above |
12 |
| 923 | Which method is used to get very pure germanium used in semiconductor? A. Vapour-phase refining B. Electrolysis c. Liquation D. zone-refining |
12 |
| 924 | During the electrolysis of carnallite, ( M g C l_{2} ) is decomposed and not ( K C l ) This is because of : A . Lower decomposition voltage of ( M g C l_{2} ) than that of ( K C l ) B. Reverse reaction ( M g C l_{2}+2 K rightarrow M g+2 K C l ) if ( K C l ) is decomposed under other experimental condition c. Both (A) and (B) D. None of the above |
12 |
| 925 | In the electrolytic reduction of alumina, the electrolyte is covered with coke powder because, if : A. prevents oxidation of aluminium formed B. reacts with aluminium forming aluminium carbide c. prevents heat loss from electrolyte D. None of the above |
12 |
| 926 | Zinc, cadmium and mercury are found in nature as sulphides. Values of standard reduction potentials for the half-reactions are : ( M^{2+}(a q)+2 e^{-} rightarrow M(s) ) ( M quad E^{circ} ) ( Z n-0.76 V ) ( C d quad-0.40 V ) ( H g+0.79 V ) Which sulphides give element not oxide on roasting? A. ( Z n S ) в. ( H g S ) c. ( C d S ) D. None of these |
12 |
| 927 | Assertion Gold and silver are extracted from their native ores by leaching. Reason Both silver and gold particles dissolve in dilute solution of sodium cynide in presence of oxygen. 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 |
| 928 | Match column A with column B and select the correct option: Column A (Ore) Column B (Nature of ore) (a) ( (b) ) (a) Copper glance ( (c) ) ( b(i i), c(i i i), d(i v) ) ( mathbf{A} cdot mathbf{a}(mathbf{i}) ) , B. ( a(text { iv }), b(text { ii) }, c(text { iii), } d(i) ) ( mathbf{c} cdot mathbf{a}(text { iii }), b(text { iv }), c(text { ii }), d(i) ) D. ( a(text { iv }), b(i), c(i i), d(text { iii }) ) |
12 |
| 929 | Question 10. What is meant by the term ‘chromatography’? | 12 |
| 930 | Which of the elements indicated by ( A, B ) ( mathrm{C} ) and ( mathrm{D} ) is expected to be found in native state? ( A cdot A ) B. B ( c cdot c ) ( D . ) D |
12 |
| 931 | Assertion Wrought iron is more malleable and ductile than steel. Reason It contains slightly less percentage of carbon. 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 and Reason is correct |
12 |
| 932 | Which of the above given curves is wrongly presented? 3. ( P b rightarrow P b O ) ( c cdot Z r rightarrow Z r O ) ( . . M g rightarrow M g O ) |
12 |
| 933 | Which of the following has more number of water of crystallisation? A. Corundum B. Gibsite c. Bauxite D. Diaspore |
12 |
| 934 | In the extraction of copper from its sulphide ore, the metal is finally obtained by the reduction of cuprous oxide with: A. copper(I) sulphide B. sulphur dioxide c. iron(II) sulphide D. carbon monoxide |
12 |
| 935 | Lead obtained from galena ore (PbS) by air reduction or carbon reduction process contains base metal (Cu, Bi, As, Sn, ( Z n ) ) as impurities. Gelatin acts as an addition agent in the electrolysis of Pb. In the presence of gelatin, Pb becomes: A. hard and brittle B. soft and rubbery c. smooth and uniform D. only brittle |
12 |
| 936 | Which reducing agent is employed to get copper from the leached low grade copper ore? |
12 |
| 937 | The froth floatation process is used for the concentration of: A. ore having low density B. ore having magnetic nature c. ore having high density D. ore having water soluble gangue |
12 |
| 938 | Predict the mode of occurrence of the following metals: The correct answer is: A. ( N a rightarrow ) combined form B. ( F e rightarrow ) combined form c. ( A u rightarrow ) combined form D. none of these |
12 |
| 939 | Phosphorus separates, in the extraction of iron, as: A ( cdot operatorname{slag}, C a_{3}left(P O_{4}right)_{2} ) B. volatile ( P_{2} O_{5} ) ( mathbf{c} cdot operatorname{slag}, M g_{3}left(P O_{4}right)_{2} ) D. ( C a_{3} P_{2} ) |
12 |
| 940 | Calcium of the lime stone added in the metallurgy of iron comes out at the end as: A ( cdot C a C O_{3} ) в. ( C a O ) c. ( operatorname{casio}_{3} ) D. None of these |
12 |
| 941 | Which of the following is not added the extraction of silver by cyanide process? A . ( N a C N ) B. Air ( c cdot Z n ) D. ( N a_{2} S_{2} O_{3} ) |
12 |
| 942 | Fusion of ( M n O_{2}, ) with ( K O H ) in presence of ( boldsymbol{O}_{2} ) produces a salt ( boldsymbol{W} ) Alkaline solution of ( W ) upon electrolytic oxidation yields another salt ( X . ) The manganese containing ions present in ( W ) and ( X, ) respectively are ( Y ) and ( Z . ) Correct statement(s) is (are) This question has multiple correct options ( mathbf{A} cdot operatorname{In} operatorname{both} Y ) and ( Z, alpha- ) bonding occurs between ( p- ) orbitals of oxygen and d-orbitals of manganese B. Both ( Y ) and ( Z ) are coloured and have tetrahedral shape C. In aqueous acidic solution, ( Y ) undergoes disproportionation reaction to give ( Z ) and ( M n O_{2} ) D. ( Y ) is diamagnetic in nature while ( Z ) is paramagnetic |
12 |
| 943 | 0.22 For the metallurgical process of which of the ores calcined ore can be reduced by carbon? (a) Haematite (b) Calamine (c) Iron pyrites (d) Sphalerite |
12 |
| 944 | Which of the following represents the composition of Carnallite mineral? A. ( K_{2} O cdot A l_{2} O_{3} cdot 6 S i O_{2} ) в. ( K N O_{3} ) c. ( K_{2} S O_{4} cdot M g S O_{4} cdot M g C l_{2} cdot 6 H_{2} O ) D. ( K C l cdot M g C l_{2} cdot 6 H_{2} O ) |
12 |
| 945 | The method of extraction of silver by cyano complex formation followed by metal displacement is called as: A. Parke’s method B. MacArthur-Forest method c. Serpeck method D. Hall’s method |
12 |
| 946 | Match List – I with List – II for the compositions of substances and select the correct answer using the code given below the list: List – – List – II Substances |
12 |
| 947 | Assertion Al obtained only by electrolytic reduction of Alumina (pure) Reason Aluminium metal has a strong affinity for oxygen and the oxide of ( mathrm{Al} ) is ( A l_{2} O_{3} ) which is a very stable oxide. Hence ordinary chemically reducing agents are not sufficient to reduce ( A l_{2} O_{3} ) to ( A l ) 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 |
| 948 | Which one is mineral of manganese? A . Magnesite B. Malachite c. Magnetite D. Pyrolusite |
12 |
| 949 | Assertion In froth floatation method, collectors such as pine oil xanthates are added to the suspension of powdered ore. Reason Collectors stabilizes the froth. |
12 |
| 950 | Aquaregia is part conc. HCl and part conc. ( boldsymbol{H} boldsymbol{N} boldsymbol{O}_{3} ) A. one,three B. one,one c. three,three D. three,one |
12 |
| 951 | 0.47 Match items of Column I with the items of Column II and assign the correct code. Column! Column II A Cyanide process 1. Ultrapure Ge B. Froth floatation process 2 Dressing of Zns C Electrolytic reduction 3. Extraction of Al D. Zone refining 4. Extraction of Au 5. Purification of Ni Codes A B C D A B C D (a) 4 2 3 1 (b) 2 3 1 5 (c) 1 2 3 4 (d) 3 4 5 1 to |
12 |
| 952 | Magnesium is manufactured by electrolysing fused magnesium chloride using. A. A nickel cathode and a graphite anode B. The iron container as anode and a nickel cathod C. The iron container as cathode and a graphite anode D. The nickel container as cathode and iron anode |
12 |
| 953 | The chief ore of aluminium is : A. bauxite B. cryolite c. alunite D. feldspar |
12 |
| 954 | Sulphide ore of zinc/copper is concentrated by: A. forth floatation B. electromagnetic process c. gravity process D. distillation |
12 |
| 955 | Match items of Column I with the items of Column II and assign the correct code with respect to Column I: ( begin{array}{llll} & text { Column I } & & text { Column II } \ text { (a) } & begin{array}{l}text { Cyanide } \ text { process }end{array} & text { (i) } & begin{array}{l}text { Ultrapure } \ text { Ge }end{array} \ text { (b) } & begin{array}{l}text { Froth } \ text { floatation } \ text { process }end{array} & text { (ii) } & begin{array}{l}text { Dressing of } \ Z n Send{array} \ text { (c) } & begin{array}{l}text { Electrolytic } \ text { reduction }end{array} & text { (iii) } & begin{array}{l}text { Extraction } \ text { of } A lend{array} \ text { (d) } & text { Zone refining } & text { (iv) } & begin{array}{l}text { Extraction } \ text { of } A uend{array} \ & text { (v) } & begin{array}{l}text { Purification } \ text { of } N iend{array}end{array} ) ( mathbf{A} cdot(i v),(i i),(i i i),(i) ) B. (ii), (iii), (i), (v) ( mathbf{C} cdot(mathrm{i}),(mathrm{ii}),(mathrm{iii}),(mathrm{iv}) ) D. (iii),(iv),(v), (i) |
12 |
| 956 | Which type of ore is concentrated by froth floatation process? | 12 |
| 957 | Which of the following processes is used in extractive metallurgy of magnesium? A. Fused salt electrolysis B. Self reduction c. Aqueous solution electrolysis D. Thermite reduction |
12 |
| 958 | The process to remove unwanted impurities from the ore is called (a) purification (b) calcination (c) bassimerisation (d) concentration |
12 |
| 959 | Which one of the following statements is incorrect about rock salt type? A . It has fcc arrangement of ( mathrm{Na}^{-} ) B. Nat and Cl-ions have a co-ordination number of 6: 6 c. A unit cell of ( N a C l ) consists of four ( N a C l ) units D. All halides of alkali metals have rock-salt type structure |
12 |
| 960 | Which of the metal ores can be obtained in hydrometallurgical reduction? |
12 |
| 961 | The substance added in water in the froth floatation process is A. Olive oil B. Pine oil c. coconut oil D. None of the above |
12 |
| 962 | Cryolite, ( N a_{3} A l F_{6} ) is added to ( A l_{2} O_{3} ) in Hall-Heroult process to ( _{—}- ) m.p. and to electrical conductivity. A. higher, increase B. higher, decrease c. lower, increase D. lower, decrease |
12 |
| 963 | Solidified ( C u ) obtained from the reverberatory furnace has blistered appearance. This is due to: A. evolution of ( C O_{2} ) gas B. evolution of ( S O_{2} ) gas C . evaporation of volatile materials D. evolution of ( N O_{2} ) |
12 |
| 964 | Give reasons: (i) Name the method of refining of nickel. (ii) What is the role of cryolite in the extraction of aluminium? (iii) What is the role of limestone in the extraction of iron from its oxides? |
12 |
| 965 | Which of the following process is used in the extractive metallugy of magnesium? A. Fused salt electrolysis B. Self reduction c. Aqueous solution electrolysis D. Thermite process |
12 |
| 966 | The oxidation state of ( C u ) and ( F e ) in Chalcopyrite is, respectively +1 and +3 A . True B. False |
12 |
| 967 | Which one of the following methods is used in the concentration of sulphide ore ? A. Froth floation B. Smelting c. Roasting D. Leaching |
12 |
| 968 | Impure copper containing ( boldsymbol{F e}, boldsymbol{A} boldsymbol{u}, boldsymbol{A} boldsymbol{g} ) as impurities is electrolytically refined. A current of ( 140 A ) for ( 482.5 s ) decreased the mass of the anode by ( 22.26 g ) and increased the mass of cathode by ( 22.011 g . ) Percentage of iron in impure copper is : (Given molar mass ( F e=55.5 g m o l^{-1} ) molar mass ( C u=63.54 g m o l^{-1} ) A .0 .85 в. 0.90 c. 0.95 D. 0.97 |
12 |
| 969 | You are living very near to sea-coast What types of minerals can be present in direct supply of tap water? ( mathbf{A} cdot N a B r ) в. ( N a I ) c. ( M g C l_{2} ) D. All the above |
12 |
| 970 | Brine is electrolysed by using inert electrodes. The reaction at anode is ( mathbf{A} cdot C l_{(a q)}^{-} rightarrow frac{1}{2} C l_{2(g)}+e^{-} ; E_{c e l l}^{0}=1.36 V ) B ( cdot 2 H_{2} O_{(l)} rightarrow O_{2(g)}+4 H^{+}+4 e^{-} ; E_{c e l l}^{0}=1.23 V ) ( mathbf{C} cdot N a_{(a q)}^{+}+e^{-} rightarrow N a_{(s)} ; E_{c e l l}^{0}=2.71 V ) ( mathbf{D} cdot H_{(a q)}^{+}+e^{-} rightarrow frac{1}{2} H_{2(g)} ; E_{c e l l}^{0}=0.00 V ) |
12 |
| 971 | 0.40 What is the role of flux in metallurgical processes? | 12 |
| 972 | Q. 42 Write down the reactions taking place in bla le reactions taking place in blast furnace related to the metallurgy of iron in the temperature range 500-800 Ans Chaminal stollurgy of iron in the |
12 |
| 973 | Zinc, not copper, is used for the recovery of metallic silver from the complex ( left[A g(C N)_{2}right]^{-}, ) explain A. zinc is more reducing and cheaper than copper. B. Zinc is less reducing and cheaper than copper. c. zinc is more reducing and higher than copper. D. None of these |
12 |
| 974 | 3. Sulphide ores are usually concentrated by (a) Gravity separation (1) Froth flotation process (c) Calcination (d) Hydraulic washing |
12 |
| 975 | The main function of frothers is to A. stick to the ore and take it to the top B. convert the insoluble ore into soluble part C. make the ore hydrophobic D. none of the above |
12 |
| 976 | ASSERTION: ( C u F e S_{2} ) is concentrated by froth floatation method. REASON: ( C u F e S_{2} ) is the main ore of |
12 |
| 977 | The ore of aluminium is : A . cryolite B. magnesite c. carnallite D. bauxite |
12 |
| 978 | Sand and sawdust can be separated by A. gravity separation B. calcination c. magnetic separation D. none of these |
12 |
| 979 | Composition of azurite mineral is: A. ( C u C O_{3} . C u O ) в. ( C uleft(H C O_{3}right)_{2} . C u(O H)_{2} ) ( mathbf{c} cdot 2 C u C O_{3} cdot C u(O H) ) D. ( C u C O_{3} .2 C u(O H) ) |
12 |
| 980 | Assertion Sulphide ores are converted to oxides before reduction. Reason Oxides are easier to reduce. 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 |
| 981 | Assertion Reduction of ( Z n O ) with carbon is done at ( 1100^{0} C ) Reason ( triangle G^{0} ) is negative at this temperature thus, process is spontaneous. 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 and Reason is correct |
12 |
| 982 | Meht tch the items of Column I with the items of Column II and assign the correct code. Column 1 A. Sapphire B Sphalerite C Depressant D. Corundum Column II Al₂O₃ 2 NaCN CO 4. Zns 5. Fe₂O₃ Codes (a) 3 (c) 2 A B 4 3 C 2 4 D 1 5 A (b) 5 (d) 1 B 4 2 C 3 3 D 2 4 |
12 |
| 983 | 17. Which of the following alloys contain tin as one of the constituents? (a) Bronze (b) Solder (c) Gun metal (d) Monel |
12 |
| 984 | The reduction of an oxide by aluminium is called A. Ellingham process B. Goldschmidts aluminothermite process c. Krolls process D. Van Arkel process |
12 |
| 985 | Match the following and select the correct answer from codes given below | 12 |
| 986 | Aluminium is obtained by the electrolysis of pure ( A l_{2} O_{3}, ) dissolved in: A. alumina B. bauxite c. cryolite and flourspar D. feldspar |
12 |
| 987 | Hydraulic washing is based on the differences in ore and gangue particles. A. specific gravities B. mass c. type of material D. none of these |
12 |
| 988 | The solubility of impurities in a metal in molten and solid states is different. This is principle involved in the refining of a metal by which of the following methods? A. Poling B. Liquation c. zone refining D. Electrolysis |
12 |
| 989 | Which of the following ores is concentrated by chemical leaching method? A. Cinnabar B. Argentite c. copper pyrites D. Galena |
12 |
| 990 | Metals are usually not found as nitrates in their ores. Out of the following two ( (a ) and ( b ) ) reasons which is /are true for the above observation? (a) Metal nitrates are highly unstable (b) Metal nitrates are highly soluble in water ( mathbf{A} cdot a ) is false but ( b ) is true B. ( a ) is true but ( b ) is false c. ( a ) and ( b ) are true D. ( a ) and ( b ) are false |
12 |
| 991 | Choose the correct statement(s) for froth flotation process, which is used for the concentration of sulphide ore. a) It is based on the difference in the ability of different minerals to become wet. b) It uses sodium ethyl xanthate, ( C_{2} H_{5} O C S_{2} N a ) as collector. c) It uses ( N a C N ) as a depressant in the mixture of ( Z n S ) and ( P b S, ) where ( Z n S ) forms soluble complex and ( P b S ) forms froth. (a) and (b) are correct A. only B. Only (b) and (c) are correct c. only (a) and (c) are correct D. All statements are correct |
12 |
| 992 | Describe the extraction of magnesium and bromine from sea water | 12 |
| 993 | The mineral carnallite contains (i) ( _{–} ) and (ii) metals. (iii) ( _{—}- ) is purified by cupellation and (iv) purified by distillation. A . (i) -calcium, (ii)- zinc, (iii)- mercury, (iv)- – tin B. (i)- calcium, (ii)- magnesium, (iii)- zinc, (iv)- – lead c. (i)- potassium, (ii)- calcium, (iii)- copper, (iv)- mercury D. (i)- magnesium, (ii)-potassium, (iii)- – silver, (iv) mercury |
12 |
| 994 | Among ( K, M g, A u ) and ( C u, ) the one which is extracted by heating its ore in air is: A. ( K ) в. ( M g ) c. ( A u ) D. ( C u ) |
12 |
| 995 | Here an extraction process is given in steps. Identify the suitable ores corresponding to the process. Pulverisation ( rightarrow ) Calcination ( rightarrow ) Smelting ( rightarrow ) Vacuum ( rightarrow ) Distillation This question has multiple correct options A. zinc blend B. Calamine c. Magnesite D. zincite |
12 |
| 996 | Boron can be obtained by various methods but not by: A. thermal decomposition of ( B_{2} H_{6} ) B. pyrolysis of ( B I_{3} ) (van Arkel) C . reducing ( B C l_{3} ) with ( H_{2} ) D. electrolysis of fused ( B C l_{3} ) |
12 |
| 997 | Which one of the following is correct? A. A mineral cannot be an ore B. An ore cannot be a mineral C. All minerals are ores D. All ores are minerals |
12 |
| 998 | Froth floatation process is used for the concentration of sulphide ores. This process is an illustration of the practical application of: A. adsorption B. absorption c. sedimentation D. coagulation |
12 |
| 999 | Which of the following technique is used in the manufacture of aluminium from bauxite? A. Reduction with magnesium B. Reduction with coke c. Electrolytic reduction D. Reduction with iron |
12 |
| 1000 | Which of the following metals are extracted by electrolytic reduction? This question has multiple correct options A. ( C u ) в. ( A l ) ( mathrm{c} cdot M g ) D. ( A g ) |
12 |
| 1001 | In the extraction of nickel by Mond process, the metal is obtained by: A. Electrochemical reduction B. Thermal decomposition c. Chemical reduction by aluminium D. Reduction by carbon |
12 |
| 1002 | Find out A from the given flowchart. ( mathbf{A} cdot C u_{2} S ) B. ( C u F e S_{2} ) ( mathbf{c} cdot operatorname{Fe} S_{2} ) ( mathrm{D} cdot mathrm{Fe}_{3} mathrm{O}_{4} ) |
12 |
| 1003 | Unsıder the IOIIOwIng melaııurgıcal processes: ( (I) ) Heating impure metal with ( C O ) and distilling the resulting volatile carbonyl (b.p. ( left.43^{0} mathrm{C}right) ) and finally decomposition at ( 150^{0}-200^{0} C ) to get the pure metal. ( (I I) ) Heating the sulphide ore in air until a part is converted to oxide and then further heating in the absence of air to let the oxide react with unchanged metal sulphide. ( (I I I) ) Electrolysisof the molten electrolyte containing approximately equal amounts of the metal chloride and ( N a C l ) to obtain the metal. The processes used for obtaining magnesium, nickel and copper are respectively: ( mathbf{A} cdot(I),(I I) ) and ( (I I I) ) B. ( (I I),(I I I) ) and ( (I) ) C ( .(I I I),(I) ) and ( (I I) ) D. ( (I I),(I) ) and ( (I I I) ) |
12 |
| 1004 | 0.28 At temperature above 1073 K, coke can be used to reduce Feo to Fe. How can you justify this reduction with Ellingham diagram? |
12 |
| 1005 | Which of the following pairs of metals is purified by van-Arkel method? A . ( N e ) and ( F e ) B. ( G a ) and ( I n ) ( mathbf{c} . Z r ) and ( T i ) D. ( A g ) and ( A u ) |
12 |
| 1006 | In Mac-Arthur Forrest method, silver is extracted from solution of ( N aleft[A g(C N)_{2}right] ) by the use of A . ( F e ) в. ( M g ) c. ( C u ) D. ( Z n ) |
12 |
| 1007 | The anode mud in the electrolyte refining of silver contains: A. ( Z n, C u, A g, A u ) в. ( Z n, ) А( g, ) Аи c. ( C u, A g, A u ) D. ( A u ) |
12 |
| 1008 | What is a concentration of ores? Explain the process with diagram by which metallic ore with sulphide as an impurity is purified. |
12 |
| 1009 | Identify the process to which the following reaction belongs: ( A l_{2} O_{3} cdot 2 H_{2} O+N a_{2} C O_{3} longrightarrow ) ( mathbf{2} N boldsymbol{a} boldsymbol{A} boldsymbol{l} boldsymbol{O}_{2}+mathbf{2} boldsymbol{H}_{2} boldsymbol{O}+boldsymbol{C} boldsymbol{O}_{2} ) ( mathbf{2} N boldsymbol{a} boldsymbol{A} boldsymbol{l} boldsymbol{O}_{2}+mathbf{2} boldsymbol{H}_{2} boldsymbol{O}+ ) ( C O_{2} 50-60^{circ} C A l_{2} O_{3} .2 H_{2} O+ ) ( N a_{2} C O_{3} ) A. Hall’s process B. Baeyer’s process C. Serpeck’s process D. None of these |
12 |
| 1010 | Which of the following metal is leached by cyanide process? ( A cdot A B ) B. Na ( c cdot A ) D. cu |
12 |
| 1011 | What is calcination? | 12 |
| 1012 | Formation of volatile ( N i(C O)_{4} ) and its subsequent heating gives pure Ni This process is called A . Hall B. Dow c. serpeck D. Mond |
12 |
| 1013 | Which of the following mixture can be separated by magnetic separation? A. Iron filings, sand and iodine B. Common salt, sand and marbles c. chalk powder, grain and chaff D. Stone, salt and water |
12 |
| 1014 | Question 18. What is the role of cryolite in the metallurgy of aluminium? calon Al 12 |
12 |
| 1015 | What is the role of depressants in the forth floatation process? | 12 |
| 1016 | ( (A g+P b) ) alloy ( frac{M e l t a n d}{Z i n c i s a d d e d}(A g+P b+ ) ( Z n) m e l t stackrel{C o o l}{longrightarrow} frac{text {Layer} X}{text {Layer} Y} ) Select the correct statement based on the above scheme: A. Layer X contains Zn and Ag B. Layer Y contains Pb and Ag but amount of silver in this layer is smaller than in layer ( x ) c. ( x ) and ( Y ) are immiscilbe layer D. All the correct statements |
12 |
| 1017 | Explain the purification of sulphide ores by froth floatation method? | 12 |
| 1018 | The powdered ore is agitated with water or washed with running stream of water The heavy ore particles and lighter impurities are separated. This method of concentration is known as: A. metallurgy B. leaching c. gravity separation D. forth floatation process |
12 |
| 1019 | CO is toxic because it forms complex with ( quad ) in the blood A. carbohydrate B. protein c. haemoglobin D. none of these |
12 |
| 1020 | All minerals are not the ore but all ores are minerals. The extraction of a particular metal depends upon several factors and overall it has to be convenient and economical. Which of the following statement is true? A. Na-ethyl xanthate is used as frother exclusively. B. Levigation cannot be applied for sulphide in any condition. C. Froth floatation can be applied for non-sulphide ore also using suitable activator D. Impurities like ( S ) and ( A ) s are removed as elemental vapor in roasting. |
12 |
| 1021 | Question 12. What is the role of flux in metallurgical processes? | 12 |
| 1022 | Which of the following statements is correct about the role of collectors added during forth floatation process? A. Collectors enhance the non-wettability of ore particles B. Collectors enhance the wettability of gangue particles c. collectors help in separating two sulphide ores present in the mixture D. collectors help ore particles to settle down below the froth |
12 |
| 1023 | In the leaching of ( A g_{2} S ) with ( mathrm{NaCN} ) a stream of air is also passed. Which of the following is the correct explanation for this step? A. Reversible nature of reaction between ( A g_{2} S ) and ( ^{N a C N} ) B. To oxidize ( N a_{2} S ) formed into ( N a_{2} S O_{4} ) and sulphur c. both (1) and (2) D. both are not suitable |
12 |
| 1024 | Which of the following methods is used for obtaining metals of very high purity? A. Distillation B. zone refiningg c. Liquation D. Electrolytic refining |
12 |
| 1025 | Elements found in native state are ( mathbb{P} ) Chlorides Silicates Carbonates Phosphates Oxides ( A cdot P b ) and ( B i ) as they are in ( p ) -block B. ( mathrm{Hg} ) and ( 0 mathrm{s} ) as they are in liquid state C. ( C ) and ( s i ) as they are non-metals D. Pt and Au as they are at the bottom of the electrochemical series |
12 |
| 1026 | Formation of metallic copper from the sulphide ore in the commercial metallurgical process involves: A ( cdot C u_{2} S+frac{3}{2} O_{2} rightarrow C u_{2} O+S O_{2} ; C u_{2} O+C rightarrow 2 C u+C O ) B. ( C u_{2} S+frac{3}{2} O_{2} rightarrow C u_{2} O+S O_{2} ; 2 C u_{2} O+C u_{2} S rightarrow 6 C u+ ) ( S O_{2} ) c. ( C u_{2} S+2 O_{2} rightarrow C u S O_{4} ; C u S O_{4}+C u_{2} S rightarrow 3 C u+ ) ( 2 S O_{2} ) D. ( C u_{2} S+frac{3}{2} O_{2} rightarrow 2 C u+S O_{2} ; C u_{2} O+C O rightarrow 2 C u+ ) ( C O_{2} ) |
12 |
| 1027 | Aluminium is obtained from ( A l_{2} O_{3} ) by A. Thermal reduction B. Hydro metallurgical method c. Electrolytic reduction D. Reduction by iron |
12 |
| 1028 | ( boldsymbol{A} boldsymbol{g}_{2} boldsymbol{S}+boldsymbol{N} boldsymbol{a} boldsymbol{C} boldsymbol{N}+boldsymbol{Z} boldsymbol{n} longrightarrow boldsymbol{A} boldsymbol{g} ) This method of extraction of Ag by complex formation and then its displacement is called A. Parke’s method B. Mac Arthur- Forrest method c. Serpeck method D. Hall’s method |
12 |
| 1029 | PP2 reactions is an example of autoreduction? Q.3 Which of the following reactions is an example of auto (a) Fe, O2 + 4CO 3 Fe + 4CO2 (b) Cu, O+C 2Cu+ CO (c) Cu2+ (aq) + Fe(s) Cu(s) + Fe2+ (aq) (d) Cu, O+Cus 3CU+ |
12 |
| 1030 | Which of the following statement is wrong? A. The fibrous nature of Wrought iron is due to the slag present in it. B. The loss of iron is Bessemer process is due to the formation of ( F e S i O_{3} ) slag. C. In Bessemer process carbon monoxide formed burns with blue flame at the mouth of the furnace. D. In blast furnace ( F e_{2} O_{3} ) is reduced to iron mainly by coke. |
12 |
| 1031 | Selection of temperature to carry out a reduction process depends so as to make: A. ( Delta G ) negative B. ( Delta G ) positive c. ( Delta H ) negative D. ( Delta H ) positive |
12 |
| 1032 | Question 3. Why is the extraction of copper from pyrites more difficult than that from its oxide ore through reduction? Consider the standard free energy of formation 4, Gº of reactants and products. More negative is A,Gº, higher is the stability. |
12 |
| 1033 | Paris green is an insecticide made from basic copper acetate, arsenious and acetic acid. A. True B. False |
12 |
| 1034 | Silver is extracted from ( A g_{2} S ) by A. fusing it with KCl and electrolyzing the melt B. reducing it with Zinc c. treating with sodium cyanide followed by zinc D. rosting it and reducing the resultant product by smelting |
12 |
| 1035 | Which of the following factors is of no significance for roasting sulphide ores to the oxides and not subjecting the sulphide ores to carbon reduction directly? A. Metal sulphides are thermodynamically more stable ( operatorname{than} C S_{2} ) B. ( C O_{2} ) is thermodynamically more stable than ( C S_{2} ) c. Metal sulphides are less stable than the corresponding oxides ( mathrm{D} cdot mathrm{CO}_{2} ) is more volatile than ( mathrm{CS}_{2} ) |
12 |
| 1036 | Question 27. Predict conditions under which Al might be expected to reduce MgO. |
12 |
| 1037 | Match the extraction processes listed in Column I with metals listed in Column ( |: ) |
12 |
| 1038 | Horn silver is: A. carbonate mineral B. chloride mineral C . sulphate mineral D. phosphate mineral |
12 |
| 1039 | 13. TUdung The process of extraction of metal from its ores, is known as (a) concentration (b) calcination (c) purification (d) metallurgy 14 Postini fub following |
12 |
| 1040 | (i) Name the method used for the refining of zirconium. (ii) What is the role of ( C O ) in the extraction of Iron? (iii) Reduction of metal oxide to metal becomes easier if the metal obtained is in the liquid state. Why? |
12 |
| 1041 | Which one of the above oxidation curve is wrongly presented in the given Gibbs free energy vs temperature graph? A. ( C rightarrow C O_{2} ) B. ( T i rightarrow T i O_{2} ) ( c, P b rightarrow P b O ) D. ( M g rightarrow M g O ) |
12 |
| 1042 | Which one of the following metals can not be extracted by using Al as a reducing agent A. ( N a ) from ( N a_{2} O ) B. ( C r ) from ( C r_{2} O_{3} ) c. ( M n ) from ( M n O_{2} ) D. Fe from ( F e_{2} O_{3} ) |
12 |
| 1043 | Question 2. What is the significance of leaching in the extraction of aluminium? |
12 |
| 1044 | The Mond process is used for the: A. extraction of ( M o ) B. purification of ( N i ) c. purification of ( Z r ) and ( T i ) D. extraction of ( Z n ) |
12 |
| 1045 | The element which could be extracted by electrolytic reduction of its oxide dissolved in a high-temperature melt is: A. sodium B. magnesium c. fluorine D. aluminium |
12 |
| 1046 | Copper is purified by: A. distillation B. liquation c. carbon-reduction D. electrolytic refming |
12 |
| 1047 | Duralumin is an alloy containing (a) Magnesium and aluminium (b) Magnesium and copper (c) Magnesium,copper and aluminium (d) Magnesium,copper, manganese and aluminium. |
12 |
| 1048 | Which among the following alloys is used in making instruments for electrical measurement? A. Stainless steel B. Manganin c. spiegeleisen D. Duralumin |
12 |
| 1049 | In the electrolytic refining of a metal ( M ) what would you take as the anode, the cathode, and the electrolyte? | 12 |
| 1050 | Froth flotation method cannot be employed for the concentration of: A. zinc blende B. Pyrolusite c. copper pyrites D. cinnabar |
12 |
| 1051 | In electro-refining, thick sheets of pure copper are obtained at: A. cathode B. anode c. electrode D. none of the above |
12 |
| 1052 | Name of metals and non-metals which obtained by electrolysis is/are respectively? This question has multiple correct options A. Sodium, Chlorine B. Magnesium, lodine c. Aluminium, Fluorine D. Iron, Cobalt |
12 |
| 1053 | 232 O. 20 Which of the following ores are concentrated by froth floatation? (a) Haematite (b) Galena (c) Copper pyrites (d) Magnetite |
12 |
| 1054 | The approximate percentage of silica in cement is : A . 5-10% B. 15-20% c. 17-25% D. 25-30% |
12 |
| 1055 | Which metal is leached from its ore by the use of ( K C N ) A. copper B. zinç c. Gold D. Iron |
12 |
| 1056 | Copper pyrites, ( C u F e S_{2}, ) is the important source of copper. 10 g of it was leached with dil. ( H_{2} S O_{4} ) and solution diluted to 1 L ( 10 mathrm{mL} ) of this solution required ( 10 mathrm{mL} ) of 0.02 ( mathrm{M} mathrm{KMnO}_{4} ) in acidic solution. What is % of ( F e ) in ( C u F e S_{2} ? ) |
12 |
| 1057 | Which of the following statement is correct? This question has multiple correct options A. Froth flotation method can only be used for sulphide ore B. Tin stone consists of wolframite as non-magnetic impurity C. In cyanide process for the extraction of silver, Zn is used as leaching agent D. Bessemerization process is used in the extraction of copper from copper pyrite |
12 |
| 1058 | 0.18 In the froth floatation process, zinc sulphide and lead sulphide can be separated by ……. (a) using collectors (b) adjusting the proportion of oil to water (c) using depressant (d) using froth stabilisers |
12 |
| 1059 | Silver ore ( +boldsymbol{C N}^{-}+boldsymbol{H}_{2} boldsymbol{O} stackrel{boldsymbol{O}_{2}}{longrightarrow}[boldsymbol{P}]+ ) ( boldsymbol{O} boldsymbol{H}^{-} ) [ begin{array}{c} downarrow boldsymbol{Z} boldsymbol{n} \ {[boldsymbol{Q}]+boldsymbol{A} boldsymbol{g}} end{array} ] In the process of extraction of silver, identify the complexes [P] and [Q]. A ( cdot P=left[A g(C N)_{4}right]^{-}, Q=left[Z n(C N)_{4}right]^{2} ) B . ( P=left[A g(C N)_{4}right]^{-}, Q=left[Z n(C N)_{6}right]^{4} ) c. ( P=left[A g(C N)_{4}right]^{3-}, Q=left[Z n(C N)_{4}right]^{2} ) D . ( P=left[A g(C N)_{2}right]^{-}, Q=left[Z n(C N)_{4}right]^{2} ) |
12 |
| 1060 | Write the name of a different stage of obtaining pure metal from its ore. Explain refining of copper by electrolysis with a diagram. |
12 |
| 1061 | Which of the following is a halide ore? A. Cassiterite B. Anglesite c. siderite D. carnallite |
12 |
| 1062 | Assertion In the extraction of ( A g, ) complex ( boldsymbol{N} boldsymbol{a}left[boldsymbol{A} boldsymbol{g}(boldsymbol{C} boldsymbol{N})_{2}right] ) is reacted with ( boldsymbol{Z} boldsymbol{n} ) Reason ( Z n ) is d-block transition metal. 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 and Reason is correct |
12 |
| 1063 | A certain metal has high concentration in the Earth’s crust and its oxides cannot be reduced by carbon. Which is the most suitable method for the extraction of such a metal? A. Alumino thermite process B. Electrolysis process c. van-Arkel’s process D. cupellation |
12 |
| 1064 | When ( Z n S ) and ( P b S ) minerals are present together, then ( N a C N ) is added to separate them in the froth flotation process as a depressant, because: A ( cdot P b(C N)_{2} ) precipitated while no effect on ( Z n S ) B. ( Z n S ) forms soluble complex ( N a_{2} Z n(C N)_{4} ) C. ( P b S ) forms soluble complex ( N a_{2} P b(C N) ) D. both ( (a) ) and ( (b) ) |
12 |
| 1065 | Which oil is used as frother in froth floatation process? A. Mustard oil B. coconut oil c. Olive oil D. Pine oil |
12 |
| 1066 | 20. Which of the following metals is extracted by the electrometallurgical method ? (a) Cu (b) Fe (c) Na (d) Ag |
12 |
| 1067 | What is the reaction occuring at the anode in Down’s process for the extraction of sodium? A ( cdot 4 O H^{-} rightarrow 2 H_{2} O+O_{2}+4 e^{-} ) B. ( N a^{+}+l e^{-} rightarrow N a ) ( mathbf{c} cdot 2 C l^{-} rightarrow C l_{2}+2 e^{-} ) D. ( N a O H rightarrow N a^{+}+O H^{-} ) |
12 |
| 1068 | Explain the leaching process of silver and gold using chemical reactions? | 12 |
| 1069 | dely 0.29 Wrought iron is the purest form of iron. Write a reaction used for the preparation of wrought iron from cast iron. How can the impurities of sulphur, silicon and phosphorus be removed from cast iron? |
12 |
| 1070 | Q. 4 A number of elements are available in earth’s crust but most abundant elements are ……. (a) Al and Fe (b) Al and Cu (c) Fe and Cu (d) Cu and Ag The Oxi Ang |
12 |
| 1071 | Consider the following statements and arrange in the order of true/false as given in the codes. ( boldsymbol{S}_{1}: ) Cuprite, limorite and Zincite are oxide ores. ( S_{2}: ) Dolomite contains ( C a C O_{3} ) and ( M g C O_{3} ) ( S_{3}: ) Chalcocyte and azurite are ores of copper. ( boldsymbol{S}_{4}: ) Feldspar and mica minerals contain aluminium. A. TT TT B. FTFF c. F F T T D. TTFT |
12 |
| 1072 | In the process of extraction of gold, Roastedgoldore ( +C N^{-}+H_{2} O stackrel{O_{2}}{rightarrow} ) ( [X]+O H^{-}[X]+Z n rightarrow[Y]+A u ) Identify the complexes [X] and [Y] A ( cdot x=left[A u(C N)_{2}^{-}right], Y=left[Z n(C N)_{4}right]^{2} ) B . ( x=left[A u(C N)_{4}right]^{3-}, Y=left[Z n(C N)_{4}right]^{2-} ) C ( cdot x=left[operatorname{Zn}(C N)_{2}right]^{-}, mathrm{Y}=left[operatorname{Zn}(C N)_{6}right]^{4-} ) D. ( x=left[Z n(C N)_{4}right]^{-}, Y=left[Z n(C N)_{4}right]^{2-} ) |
12 |
| 1073 | Consider the following statements and arrange in the order of true/false as given in the codes. ( S_{1}: ) In extraction of iron from haematite ore, the reduction reactions take place in the lower temperature range and in the higher temperature range, in the blast furnace. ( S_{2}: ) Sphalerite is a carbonate ore of zinc. ( S_{3}: ) The principal ore of aluminium, bauxite, usually contains silica, iron oxides and titanium oxide as impurities ( S_{4}: ) Solified copper obtained from silica lined convertor (Bessemer converter) has blistered appearance due to the evolution of ( boldsymbol{S O}_{2} ) ( mathbf{A} cdot ) Т ( F T T ) B. FTFF c. F FTT D. TF F T |
12 |
| 1074 | Draw a neat and labelled diagram of zone refining process. | 12 |
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