JEE Main 2020 — Electrochemistry Question with Solution

On applyinf Nernst equation-

$$\begin{gathered} \mathrm{E}=\mathrm{E}°-\frac{0.0591}{\mathrm{n}}\mathrm{logQ} \\ \mathrm{E}=-1.23-\frac{0.0591}{4}\log {\left[{\mathrm{H}}^{+}\right]}^4 \end{gathered}$$
$=1.23+0.0591\times pH=-1.23+0.0591\times 5$
$=-1.23+0.2955=-0.9345V=-0.93V$

The Nernst equation defines the relationship between cell potential to standard potential and to the activities of the electrically active (electroactive) species. It relates the effective concentrations (activities) of the components of a cell reaction to the standard cell potential.