The standard electromotive force of the cell : $\mathrm{Fe} \left|{\mathrm{Fe}}^{2+}\left(\mathrm{aq}\right)\right|\left|{\mathrm{Cd}}^{2+}\right|\mathrm{Cd}$ is $0.0372 \mathrm{V}$. The temperature coefficient of e.m.f. is $-0.125 {\mathrm{VK}}^{-1}$. Calculate the quantities $\mathrm{\Delta G}°, \mathrm{\Delta H}°$ ${\mathrm{\Delta S}}^{°}$and at $25° \mathrm{C}$.

At equimolar concentrations of ${\mathrm{Fe}}^{2+}$ and ${\mathrm{Fe}}^{3+}$, what must $\left[{\mathrm{Ag}}^{+}\right]$ be so that the voltage of the galvanic cell from the $\left({\mathrm{Ag}}^{+}\mid \mathrm{Ag}\right)$ and $\left({\mathrm{Fe}}^{3+}\mid {\mathrm{Fe}}^{2+}\right)$ electrodes equals zero?

${\mathrm{Fe}}^{2+}+{\mathrm{Ag}}^{+}\rightleftharpoons {\mathrm{Fe}}^{3+}+\mathrm{Ag}$,

${\mathrm{E}}_{{\mathrm{Ag}}^{+}\mid \mathrm{Ag}}=0.7991; {\mathrm{E}}_{{\mathrm{Fe}}^{3+}\mid {\mathrm{Fe}}^{2+}}=0.771$