JEE Main 2021 — Electrochemistry Question with Solution

Standard electrode potential is a measurement of the potential for equilibrium. There is a potential difference between the electrode and the electrolyte called the potential of the electrode. When unity is the concentrations of all the species involved in a semi-cell, the electrode potential is known as the standard electrode potential.

${\mathrm{E}}_1^0+2{\mathrm{E}}_2^0=3{\mathrm{E}}_3^0$
${\mathrm{E}}_1^0=3{\mathrm{E}}_3^0-2{\mathrm{E}}_2^0$

$=3(-0.036)-2(-0.44)$
$=+0.772 \mathrm{V}$
${\mathrm{E}}_{\text{cell }}^0={\mathrm{E}}_{{\mathrm{Fe}}^{3+}/{\mathrm{Fe}}^{2+}}^0+{\mathrm{E}}_{{\mathrm{I}}^{-}/{\mathrm{I}}_2}^0=0.233$
${\Delta }_{\mathrm{r}}{\mathrm{G}}^0=-2\times 96.5\times 0.233=-45 \mathrm{kJ}$