The mass of silver (Molar mass of Ag: 108 gmol ^ - 1 ) displaced by...

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

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  ${O}_{2}$ liberated.
Let $x$ gm silver displaced,
(Molar volume of gas at STP $= 22 . 4L$ )

Number equivalents of a substance = The number of moles of substance $\times$ Valence factor of that substance
$\dfrac{x \times 1}{108} = \dfrac{5 . 6}{22 . 4} \times 4, x = 108gm .$