Chemistry - Electrochemistry Question with Solution | TestHub

$\begin{array}{lll}\text{ Cathode }& (\mathrm{Ag}+(\mathrm{aq})+{\mathrm{e}}^{-}& \to \mathrm{Ag})\times 2\\ \text{ Anode }& \mathrm{Mg}& \to {\mathrm{Mg}}^{2+}(\mathrm{aq})+2{\mathrm{e}}^{-}\end{array}$
By Nernst equation $\begin{array}{rl}& {\mathrm{E}}_{\text{cell }}={\mathrm{E}}_{\mathrm{cell}}^{\circ }-\frac{\mathrm{RT}}{\mathrm{nF}}\ln \mathrm{Q}\\ & {\mathrm{E}}_{\text{cell }}={\mathrm{E}}_{\mathrm{cell}}^{\circ }-\frac{\mathrm{RT}}{\mathrm{nF}}\ln \frac{\left[{\mathrm{Mg}}^{2+}\right]}{{\left[{\mathrm{Ag}}^{+}\right]}^2}\\ & ={\mathrm{E}}_{\text{cell }}^{\circ }+\frac{\mathrm{RT}}{2\mathrm{F}}\ln \frac{{\left[{\mathrm{Ag}}^{+}\right]}^2}{\left[{\mathrm{Mg}}^{2+}\right]}\end{array}$