The weight of silver (at. wt. = 108) displaced by a quantity of electricity which displaces 5600 mL of $O_2$ At STP will be

Number of moles of O₂ at $\text{ STP }=\frac{5600}{22400}=\frac{1}{4}mol$
1 mole of oxygen produces 4 moles of electrons and 1 mole of silver requires 1 mole of electrons.
According to Faraday’s II Law,
$\begin{array}{l}\frac{W_{Ag}}{W_{O_2}}=\frac{E_{Ag}}{E_{O_2}}\\ E_{Ag}=\frac{M_{Ag}}{1};E_{O_2}=\frac{M_{O_2}}{4}\\ \frac{W_{Ag}}{M_{Ag}}\times 1=\frac{W_{O_2}}{M_{O_2}}\times 4\\ \frac{W_{Ag}}{M_{Ag}}=1\\ W_{Ag}=M_{Ag}=108gm\end{array}$