Question

Assertion : To obtain maximum work from a galvanic cell charge has to be passed reversibly.
Reason : The reversible work done by a galvanic cell is equal to decrease in its Gibbs energy.

• A. If both assertion and reason are true and reason is the correct explanation of assertion
• B. If both assertion and reason are true but reason is not the correct explanation of assertion
• C. If assertion is true but reason is false
• D. If both assertion and reason are false

Answer 1

Answer: (A)

Electrical work done in one second is equal to electrical potential multiplied by total charge.If we want to obtain maximum work from a galvanic cell then charge has to be passed reversibly. The reversible work done by a galvanic cell is equal to decrease in its Gibbs energy and therefore, if the emf of cell is $E$ and $nF$ is the amount of charge passed and $\Delta G$ is the Gibbs energy of reaction then, $\Delta G=-nF{E}_{\text{cell }}$