Chemistry - Electrochemistry Question with Solution | TestHub

$\mathrm{\Delta }{\mathrm{G}}^{\mathrm{o}}=-\mathrm{n}{\mathrm{E}}^{\mathrm{o}}\mathrm{F}$

$\mathrm{F}{\mathrm{e}}^{2+}+2{\mathrm{e}}^{-}\to \mathrm{F}\mathrm{e}$.....(i)

$\mathrm{\Delta }{\mathrm{G}}^{\mathrm{o}}=-2\times \mathrm{F}\times (-\text{0.440}\hspace{0.33em}\mathrm{V})=\text{0.880}\hspace{0.33em}\mathrm{F}$

$\mathrm{F}{\mathrm{e}}^{3+}+3{\mathrm{e}}^{-}\to \mathrm{F}\mathrm{e}$.....(ii)

${\text{ΔG}}^{\text{o}}=-3\times \text{F}\times \left(-\text{0}\text{.036}\right)=\text{0}\text{.108}\text{F}$

On subtracting equation (i) from (ii)

$\mathrm{F}{\mathrm{e}}^{3+}+{\mathrm{e}}^{-}\to \mathrm{F}{\mathrm{e}}^{2+}$

${\text{ΔG}}^{\text{o}}=\text{0}\text{.108}\text{F}-\text{0}\text{.880}\text{F}=-\text{0}\text{.772}\text{F}$

${\mathrm{E}}^{\mathrm{o}}$for the reaction$=-\frac{\mathrm{\Delta }{\mathrm{G}}^{\mathrm{o}}}{\mathrm{n}\mathrm{F}}=-\frac{(-\hspace{0.33em}\text{0.772}\hspace{0.33em}\mathrm{F})}{1\times \mathrm{F}}\text{=+}\hspace{0.33em}\text{0.772}\hspace{0.33em}\mathrm{V}$