Question

The number of correct statements from the following is ______
A. E^cell is an intensive parameter
B. A negative E^θ means that the redox couple is a stronger reducing agent than the H^– H₂ couple.
C. The amount of electricity required for oxidation or reduction depends on the stoichiometry of the electrode reaction.
D. The amount of chemical reaction which occurs at any electrode during electrolysis by a current is proportional to the quantity of electricity passed through the electrolyte.

Answer 1

Correct Answer: 4

A. \( E_{\text{cell}} \) is an intensive parameter.

• This statement is correct. Intensive properties are independent of the amount of substance present.
• \( E_{\text{cell}} \) depends on the nature of the redox reaction, concentrations, and temperature but not on the size of the electrochemical cell.

B. A negative \( E^\circ \) means that the redox couple is a stronger reducing agent than the \( \text{H}^+/\text{H}_2 \) couple.

• This statement is correct. A negative standard electrode potential (\( E^\circ \)) indicates that the redox couple has a greater tendency to lose electrons (be oxidized) compared to the standard hydrogen electrode (\( E^\circ = 0 \, \text{V} \)).
• Thus, the redox couple with a negative \( E^\circ \) is a stronger reducing agent.

C. The amount of electricity required for oxidation or reduction depends on the stoichiometry of the electrode reaction.

• This statement is correct. The amount of electricity required is proportional to the number of electrons transferred in the balanced half-reaction, as described by Faraday’s laws of electrolysis.

D. The amount of chemical reaction that occurs at any electrode during electrolysis by a current is proportional to the quantity of electricity passed through the electrolyte.

• This statement is correct. This is a direct statement of Faraday’s first law of electrolysis, which states that the chemical reaction at the electrode is proportional to the electric charge passed.

Final Answer:

All four statements (A, B, C, and D) are correct.