Question

What is the electrode potential (in $V$ ) of the following electrode at $25^{\circ} C$ ? $Ni ^{2+}(0.1\, M ) \mid Ni (s)$ (Standard reaction potential of $Ni ^{2+}$ |Ni is $\left.-0.25\, V, \frac{2.303\, R T}{F}=0.06\right)$

• A. - 0.28 V
• B. - 0.34 V
• C. - 0.82 V
• D. - 0.22 V

Answer 1

Answer: (A)

- 0.28 V

Answer 2

$E_{\text {cell }}^{\circ} =E_{\text {cell }}^{\circ}-\frac{2.303 R T}{n F} \log \left[\frac{[ Ni ]}{\left[ Ni ^{2+}\right]}\right]$
$=-0.25-\frac{0.06}{2} \log \left(\frac{1}{0.1}\right) (\because n=2)$
$=-0.25-0.03 \times 1$
$E_{\text {cell }} =-0.28\, V$