Question

Assertion (A) A negative value of $E^{\circ}$ means that the redox couple is a weaker reducing agent than the $H ^{+} / H _{2}$ couple.
Reason (R) A negative $E^{\circ}$ means that the redox couple is stronger reducing agent than the $H ^{+} / H _{2}$.

• A. Both $A$ and $R$ are correct; $R$ is the correct explanation of $A$.
• B. Both $A$ and $R$ are correct; $R$ is not the correct explanation of $A$.
• C. $A$ is correct; $R$ is incorrect.
• D. $A$ is incorrect; $R$ is correct.

Answer 1

Answer: (D)

As we know $H ^{+} / H _{2}$ couple has zero standard reduction potential so, ions having positive $E^{\circ}$ value are weaker reducing agent, while ions having negative $E^{\circ}$ value are stronger reducing agent.
Thus, $A$ is incorrect and $R$ is correct.