Question

The reduction potential of a $0.01M$ hydrogen electrode is:

• A. $0.059V$
• B. $-0.059V$
• C. $-0.118V$
• D. $0.118V$

Answer 1

The correct option is C $-0.118V$

At hydrogen electrode, $H^{+}+e^{-}⟶\frac{1}{2}{H}_2$.
$E_{cell}=E_{cell}^{\circ }-\frac{0.059}{z}log\frac{1}{\left[H^{+}\right]}$
$E_{cell}=E_{cell}^{\circ }-\frac{0.059}{1}log\frac{1}{\left[H^{+}\right]}$
$E_{cell}=0-0.059\times log(10{)}^2$
$E_{cell}=-2\times 0.059V$

$E_{cell}=-0.118V$

Hence, the correct option is $\text{C}$