Explain Faraday's second law of electrolysis.

Explain the feasibility of the following reaction :

$\mathrm{Zn}+{\mathrm{Cu}}^{2+}⟶{\mathrm{Zn}}^{2+}+\mathrm{Cu}$

Give that the standard electrode potential for ${\mathrm{Zn}}^{2+}/\mathrm{Zn}$ and ${\mathrm{Cu}}^{2+}/\mathrm{Cu}$ are $-0.76 \mathrm{V}$ and $+0.33 \mathrm{V}$ respectively:

Is the following reaction feasible? Explain.
${\mathrm{Ag}}^{+}+{\mathrm{Fe}}^{2+}⟶\mathrm{Ag}+{\mathrm{Fe}}^{3+}$

Given: ${\mathrm{E}}_{{\mathrm{Ag}}^{+}/\mathrm{Ag}}^{\Theta }=0.80 \mathrm{V}$ and ${\mathrm{E}}_{{\mathrm{Fe}}^{3+}/{\mathrm{Fe}}^{2+}}^{\Theta }=0.77 \mathrm{V}$