Question

How much will the reduction potential of a hydrogen electrode change when its solution initially at $\mathrm{p}\mathrm{H}=0$ is neutralised to $\mathrm{p}\mathrm{H}=7$

• A. Increase by 0.059 V
• B. Decrease by 0.059 V
• C. Increase by $0.41\mathrm{V}$
• D. Decrease by $0.41\mathrm{V}$

Answer 1

Answer: (D)

$\mathrm{E}={\mathrm{E}}^{\mathrm{o}}-\frac{0.0591}{\text{'}n\text{'}}\log \frac{1}{\left[{\mathrm{H}}^{+}\right]}$
$\mathrm{E}=0-\frac{0.0591}{\mathrm{1p}}{\mathrm{H}}^{}$
If $\mathrm{p}\mathrm{H}=0$ $\mathrm{E}=0$
If $\mathrm{p}\mathrm{H}=7$ $\mathrm{E}=\frac{-0.0591}{1}\times 7=-0.4137$