Given Molar mass of $\mathrm{Ag}:108 {\mathrm{gmol}}^{-1}$

Equal equivalents of substances deposited or liberated when some quantity of electricity passed through circuite in the electrolysis cell.

Equivalents of silver deposited= Equivalents of  ${\mathrm{O}}_2$ liberated.
Let $\mathrm{x}$ gm silver displaced,
(Molar volume of gas at STP $=22.4\mathrm{L}$ )

Number equivalents of a substance = The number of moles of substance $\times$ Valence factor of that substance
$$\begin{gathered} \frac{\mathrm{x}\times 1}{108}=\frac{5.6}{22.4}\times 4, \\ \mathrm{x}=108 \mathrm{gm}. \end{gathered}$$