Question

The standard electrode potential for \(\text{Ag}_{(aq)}^{+}+e^{-}\rightarrow \text{Ag}_{(s)}\) is \(0.79\) V. What is the standard potential for the reaction: \(2\text{Ag}_{(s)}\rightarrow 2\text{Ag}_{(aq)}^{+}+2e^{-}\).

• A. \(+1.58\) V
• B. \(-1.58\) V
• C. \(+0.79\) V
• D. \(-0.79\) V

Hint:

Reversing a reaction changes the sign of the potential, and multiplying by a coefficient does not change it.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept
Electrode potential is an intensive property and does not depend on the amount or coefficients in the equation.

Step 2: Reverse the Reaction
\(\text{Ag}^{+}+e^{-}\rightarrow\text{Ag}\) has \(E^{o}=+0.79\) V.
The reverse oxidation \(\text{Ag}\rightarrow\text{Ag}^{+}+e^{-}\) has \(E^{o}=-0.79\) V.

Step 3: Multiply by 2
Multiplying the equation by 2 gives \(2\text{Ag}\rightarrow2\text{Ag}^{+}+2e^{-}\).
The potential stays \(-0.79\) V, not \(-1.58\) V.

Step 4: Compare the options
The value matches option (D).

Final Answer:
The standard potential is minus 0.79 V. \[ \boxed{\text{(D) }\text{-0.79 V}} \]