Question

The potential of hydrogen electrode having a solution of $pH=4$ at $25^{\circ }C$ is

• A. −0.177 V
• B. -0.236 V
• C. + 0.177 V
• D. + 0.236 V

Answer 1

Answer: (B)

$E=E^{\circ }-\frac{0.059}{n}\log \frac{1}{\left[M^{n+}\right]}$
$=0-\frac{0.059}{1}\log \left[\frac{1}{10^{-4}}\right]$
$=-0.236V$