41. The potential of a galvanic cell is directly proportional to:
- a) The number of electrons transferred
- b) The concentration of the electrolytes
- c) The distance between the electrodes
- d) The surface area of the electrodes
Answer: b) The concentration of the electrolytes
Explanation: According to the Nernst equation, the potential of a galvanic cell depends on the concentrations of the reactants and products in the cell.
42. Which of the following is a primary cell?
- a) Lead-acid battery
- b) Nickel-cadmium battery
- c) Dry cell
- d) Lithium-ion battery
Answer: c) Dry cell
Explanation: A dry cell is a primary cell that is not rechargeable. Once its chemicals are used up, it cannot be reused.
43. The electrolyte in a molten sodium chloride electrolytic cell is:
- a) Sodium hydroxide
- b) Sodium chloride
- c) Sodium metal
- d) Sodium carbonate
Answer: b) Sodium chloride
Explanation: In the electrolysis of molten sodium chloride (NaCl), the electrolyte is molten NaCl, which decomposes into sodium metal and chlorine gas.
44. During the corrosion of iron, which of the following is produced at the cathodic region?
- a) Fe²⁺ ions
- b) OH⁻ ions
- c) Fe³⁺ ions
- d) H₂ gas
Answer: b) OH⁻ ions
Explanation: In the corrosion process, hydroxide ions (OH⁻) are formed in the cathodic region as oxygen is reduced, contributing to the formation of rust (Fe(OH)₃).
45. Which of the following materials is used as the anode in a common alkaline battery?
- a) Zinc
- b) Copper
- c) Lead
- d) Silver
Answer: a) Zinc
Explanation: In an alkaline battery, the anode is made of zinc, and it undergoes oxidation to generate electrical energy.
46. The standard electrode potential for a half-reaction is measured relative to:
- a) Standard hydrogen electrode (SHE)
- b) Calomel electrode
- c) Silver-silver chloride electrode
- d) Platinum electrode
Answer: a) Standard hydrogen electrode (SHE)
Explanation: The standard electrode potential of a half-reaction is measured relative to the standard hydrogen electrode (SHE), which has a potential of 0V.
47. In a lead-acid battery, the electrolyte used is:
- a) Sulfuric acid
- b) Hydrochloric acid
- c) Nitric acid
- d) Phosphoric acid
Answer: a) Sulfuric acid
Explanation: A lead-acid battery uses sulfuric acid as the electrolyte, which facilitates the electrochemical reactions between the lead and lead dioxide electrodes.
48. Which metal is used as the cathode in a copper refining electrolytic cell?
- a) Copper
- b) Zinc
- c) Iron
- d) Silver
Answer: a) Copper
Explanation: In the electrolytic refining of copper, a pure copper cathode is used, and copper ions from the anode are deposited on the cathode during the process.
49. Which of the following statements about fuel cells is correct?
- a) Fuel cells convert chemical energy into electrical energy continuously
- b) Fuel cells can only be used once
- c) Fuel cells store electrical energy like batteries
- d) Fuel cells require a solid fuel to operate
Answer: a) Fuel cells convert chemical energy into electrical energy continuously
Explanation: Fuel cells continuously convert chemical energy into electrical energy as long as fuel and an oxidant are supplied, without needing recharging.
50. The Daniell cell consists of which of the following electrodes?
- a) Zinc and copper
- b) Iron and silver
- c) Nickel and zinc
- d) Copper and magnesium
Answer: a) Zinc and copper
Explanation: A Daniell cell consists of a zinc electrode in zinc sulfate solution and a copper electrode in copper sulfate solution, generating a potential difference between the two.
Leave a comment