Question

In the cell reaction \(\text{Cu(s)} + 2\text{Ag}^+(\text{aq}) \rightarrow \text{Cu}^{2+}(\text{aq}) + 2\text{Ag(s)}\), \(E^\circ_{\text{cell}} = 0.46\,\text{V}\). By doubling the concentration of \(\text{Cu}^{2+}\), \(E_{\text{cell}}\) is:

• A. doubled
• B. halved
• C. increases but less than double
• D. decreases by a small fraction

Hint:

Increase in product concentration lowers the cell potential.

Answer 1

The Correct Option is D

Step 1: Nernst equation: \[ E = E^\circ - \frac{0.059}{2}\log Q \]
Step 2: Doubling \([\text{Cu}^{2+}]\) increases reaction quotient \(Q\).
Step 3: Hence, cell potential decreases slightly.