Question

The correct representation of Nernst’s equation for half-cell reaction
$Cu^{2+}\left(aq\right) +e^{-}\to Cu^{+} \left(aq\right)$ is

• A. $E^{\circ}_{Cu^{+}, Cu^{2+}} = E^{\circ}_{Cu^{+},Cu^{2+}} - \frac{0.0592}{2} log \frac{\left[Cu^{+}\right]}{\left[Cu^{2+}\right]}$
• B. $E_{Cu^{+}, Cu^{2+}} = E^{\circ}_{Cu^{+},Cu^{2+}} - \frac{0.0592}{1} log \frac{\left[Cu^{+}\right]}{\left[Cu^{2+}\right]}$
• C. $E^{\circ}_{Cu^{+}, Cu^{2+}} = E_{Cu^{+},Cu^{2+}} - \frac{0.0592}{2} log \frac{\left[Cu^{+}\right]}{\left[Cu^{2+}\right]}$
• D. $E_{Cu^{+}, Cu^{2+}} = E^{\circ}_{Cu^{+},Cu^{2+}} - \frac{0.0592}{1} log \frac{\left[Cu^{+}\right]}{\left[Cu^{2+}\right]}$

Answer 1

Answer: (B), (D)

Key Idea General Nernst equation for a reaction is given as

$E_{\text {call }}=E^{\circ}_{\text {cell }}-\frac{0.0591}{x} \log \frac{[P]}{[R]}$

For the half-cell

$Cu ^{2+}(aq)+e^{-} \to Cu ^{+}(a q)$

The correct Nernst's equation is

$E_{Cu^{+}}, Cu^{2+}=E^{\circ}_{Cu^{+}}, Cu^{2+}-\frac{0.0591}{1} log \frac{\left[Cu^{+}\right]}{\left[Cu^{2+}\right]}$