2. Electrochemistry

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1. In a dry Leclanche cell, the cathode is made of?
   A) Zinc container  |  B) MnO2  |  C) Graphite rod  |  D) NH4Cl
2. What is the voltage of a dry cell?
   A) 1.10V  |  B) 1.5V  |  C) 6V  |  D) 1.35V
3. In a Daniell cell, the cathode is made of?
   A) Zn  |  B) Na  |  C) C  |  D) Cu
4. Which cell is used in vehicle batteries and inverters?
   A) Mercury cell  |  B) Dry cell  |  C) Lead storage cell  |  D) Fuel cell
5. The potential of which cell remains constant?
   A) Dry cell  |  B) Daniell cell  |  C) Mercury cell  |  D) All of the above
6. Which of the following is a secondary cell?
   A) Lead storage cell  |  B) Mercury cell  |  C) Dry cell  |  D) All of the above
7. How much electricity is required to liberate 108 grams of silver from silver nitrate solution?
   A) 1 Ampere  |  B) 1 Coulomb  |  C) 1 Faraday  |  D) 2 Ampere
8. What are used as fuels in a fuel cell?
   A) Hydrogen  |  B) Methane  |  C) Methanol  |  D) All of the above
9. Which of the following is not a conductor?
   A) Metal  |  B) Molten salt  |  C) Electrolyte  |  D) Solid NaCl
10. What is the effect of increasing dilution on specific conductivity?
    A) Increases  |  B) Decreases  |  C) Remains constant  |  D) Becomes zero
11. The approximate value of 1 Faraday (F) is?
    A) 96500 C  |  B) 96000 C  |  C) 1.6 x 10^-19 C  |  D) 3.175 C
12. The 'Zn' electrode used to prevent corrosion is called?
    A) Sacrificial electrode  |  B) Inert electrode  |  C) Standard electrode  |  D) Electrolyte
13. An electrochemical cell converts what into what?
    A) Mechanical to electrical  |  B) Electrical to chemical  |  C) Chemical to electrical  |  D) Heat to electrical
14. The unit of cell constant is?
    A) cm  |  B) cm⁻¹  |  C) ohm cm  |  D) S cm²
15. Who gave the laws of electrolysis?
    A) Faraday  |  B) Ostwald  |  C) Arrhenius  |  D) Kohlrausch
16. Rusting of iron is what type of reaction?
    A) Photochemical  |  B) Electrochemical  |  C) Displacement  |  D) Decomposition
17. What is the SI unit of resistivity?
    A) Ohm cm  |  B) Ohm meter  |  C) Ohm  |  D) Ampere
18. What is the electrode potential of the Standard Hydrogen Electrode?
    A) 2.6  |  B) -1.10  |  C) 0  |  D) +1.76
19. What is the unit of molar conductivity?
    A) ohm⁻¹ mol⁻¹  |  B) ohm⁻¹  |  C) ohm⁻¹ cm⁻¹  |  D) ohm⁻¹ m² mol⁻¹
20. The ratio of distance between electrodes (l) and cross-sectional area (A) of a cell is called?
    A) Resistivity  |  B) Molar conductivity  |  C) Cell constant  |  D) Resistance
21. If a Redox reaction is occurring in a cell, the value of emf will be?
    A) One  |  B) Positive  |  C) Zero  |  D) Negative
22. What will be obtained at the electrodes on electrolysis of molten NaCl?
    A) Cl2 and Na  |  B) Cl2 and H2  |  C) O2 and Na  |  D) Na and H2
23. The correct order of reactivity of Mg, Cu, Na and Au is?
    A) Au>Cu>Mg>Na  |  B) Na>Mg>Cu>Au  |  C) Mg>Cu>Au>Na  |  D) Na>Cu>Mg>Au
24. The metal which cannot displace H2 from hydrochloric acid (HCl)?
    A) Zn  |  B) Cu  |  C) Mg  |  D) Al
25. Which of the following reactions is not possible?
    A) Na + AgCl → NaCl + Ag  |  B) CaO + H2 → Ca + H2O  |  C) CuO + H2 → Cu + H2O  |  D) Fe + 2HCl → FeCl2 + H2
26. Which of the following metals is most easily oxidized?
    A) Cu  |  B) Ag  |  C) Au  |  D) Al
27. Which of the following oxides will be reduced by hydrogen?
    A) Al2O3  |  B) MgO  |  C) ZnO  |  D) Ag2O
28. Which cell was used in the Apollo space program?
    A) Dry cell  |  B) Lead storage cell  |  C) Mercury cell  |  D) H2-O2 Fuel cell
29. Among the following, the strongest reducing agent is?
    A) Li  |  B) K  |  C) Na  |  D) Cs
30. What will happen if an external potential greater than cell potential E° is applied?
    A) Current will stop  |  B) Reaction will reverse  |  C) Cell will burst  |  D) No effect
31. Why does the molar conductivity of a weak electrolyte increase rapidly on increasing dilution?
    A) Ionization increases rapidly  |  B) Ionization decreases  |  C) Remains same  |  D) None
32. Which cell is used in hearing aids for the hearing impaired?
    A) Lead storage  |  B) Mercury cell  |  C) Dry cell  |  D) Fuel cell
33. Which of Zn, Ag, Au and Cu will react with acid to release H2 gas?
    A) Au  |  B) Ag  |  C) Cu  |  D) Zn
34. What happens on increasing the dilution of an electrolyte solution?
    A) Conductivity increases  |  B) Specific conductivity decreases  |  C) Molar conductivity increases  |  D) All of the above
35. What is the required condition for standard electrode potential E°?
    A) 25° C temperature  |  B) 1 atm pressure  |  C) 1 M concentration  |  D) All of the above
36. What will happen if the salt bridge is removed from a Daniell cell?
    A) Current will keep flowing  |  B) Potential will become zero  |  C) Potential will increase  |  D) Cell will burst
37. Which statement is false for an electrochemical cell?
    A) Cathode with higher E°  |  B) It has two electrodes  |  C) EMF is always negative  |  D) It converts chemical to electrical
38. What converts the chemical energy of hydrogen and oxygen into electrical energy?
    A) Mercury cell  |  B) Daniell cell  |  C) Fuel cell  |  D) Lead storage cell
39. The inert electrolyte used in a salt bridge is?
    A) NaCl  |  B) KCl  |  C) NaOH  |  D) KOH
40. What is the charge on the anode in an electrolytic cell?
    A) Negative  |  B) Positive  |  C) Neutral  |  D) None
41. How many Faradays of charge are required for the oxidation of 1 mole of H2O to O2?
    A) 1 F  |  B) 4.44 F  |  C) 2 F  |  D) 3 F
42. How much electricity is required to deposit 1 mole of Al from AlCl3 solution?
    A) 0.33 F  |  B) F  |  C) 3 F  |  D) 1 F
43. If 1.8g of metal is deposited by passing 3A current for 50 minutes, the equivalent weight will be?
    A) 20.5  |  B) 25.8  |  C) 19.3  |  D) 30.7
44. How much Cu will be liberated from CuSO4 solution by 96500 Coulombs of electricity?
    A) 63.5g  |  B) 31.75g  |  C) 96500g  |  D) 100g
45. If the radius of a wire is 7cm and length is 154cm, what will be the cell constant (l/A)?
    A) 1 cm⁻¹  |  B) 0.1 cm⁻¹  |  C) 5 cm⁻¹  |  D) 7 cm⁻¹
46. The charge (in Coulombs) required to reduce 1 mole of Al³⁺ to Al is?
    A) 96500 C  |  B) 193000 C  |  C) 289500 C  |  D) 10500 C
47. How many Faradays are required to obtain 36 grams of Al from molten Al2O3?
    A) 1  |  B) 2  |  C) 3  |  D) 4
48. If E° for Ca²⁺/Ca is -2.87 V, then the standard reduction potential will be?
    A) 2.87 V  |  B) 1.44 V  |  C) -1.44 V  |  D) -2.87 V
49. What will happen if a 1.10V cell is connected in the external circuit opposite to a Daniell cell?
    A) Direction of current changes  |  B) Cu dissolves  |  C) Cell stops working  |  D) Zn deposits
50. The charge (C) required to oxidize 1 mole of FeO to Fe2O3 is?
    A) 195000 C  |  B) 96500 C  |  C) 289500 C  |  D) 10500 C
51. When an aqueous solution of sodium sulfate (Na2SO4) is electrolyzed, what is obtained at the cathode?
    A) Na  |  B) H2  |  C) SO2  |  D) O2
52. The mass of Cu deposited by electrolyzing CuSO4 with 2.5A current for 5 minutes will be?
    A) 0.786 g  |  B) 0.2448 g  |  C) 1.245 g  |  D) 2.7855 g
53. What is the effect of increasing the value of E° on the thermal stability of metal oxides?
    A) Increases  |  B) Decreases  |  C) Remains constant  |  D) Becomes zero
54. What is false for a Daniell cell: 'Cu dissolves into the solution from the rod' whereas in reality?
    A) Zn dissolves  |  B) Cu deposits  |  C) Both are true  |  D) None
55. The reaction occurring at the cathode in electrolysis is called?
    A) Oxidation  |  B) Reduction  |  C) Neutralization  |  D) Hydration
56. The correct mathematical form of Kohlrausch's law for molar conductivity at infinite dilution is?
    A) Λ = λ+ + λ-  |  B) Λ = λ+ - λ-  |  C) Λ = λ+ / λ-  |  D) Λ = λ+ * λ-
57. The amount of substance deposited by one Faraday of electricity is called?
    A) Molecular weight  |  B) Equivalent weight  |  C) Electrochemical equivalent  |  D) Mass
58. According to Nernst Equation, cell potential depends on?
    A) Temperature  |  B) Concentration  |  C) Nature of electrode  |  D) All of the above
59. For Zn²⁺ + 2e⁻ -> Zn, E° = -0.76V. This indicates that Zn is?
    A) Strong oxidizing agent  |  B) Strong reducing agent  |  C) Inert  |  D) None
60. The efficiency of a fuel cell is generally?
    A) 40%  |  B) 70-75%  |  C) 90%  |  D) 100%