Question

The potential of a hydrogen electrode in a solution with pH = 5 at ${25}^{\circ }C$ is:

• A. $+0.059$
• B. $0.59$
• C. $-0.295$
• D. $0.295$

Answer 1

The correct option is C $-0.295$

$E=E^o-\frac{0.0591}{1}log\frac{1}{\left[H^{+}\right]}{H}^{+}+e^{-}⟶\underset{1atm}{\underset{}{\frac{1}{2}}}{H}_{2}E=0-\frac{0.0591}{1}log\frac{1}{{10}^{-5}}(pH=-log\left[H^{+}\right],\left[H^{+}\right]={10}^{-5})E=-0.0591\times 5=-0.295$