An electric current is passed through two electrolytic cells connected in series.One containing a solution of silver nitrate and the other solution of $H_2SO_4$.What volume of oxygen measured at $25^{\large\circ}C$ and 750mm of Hg would be liberated from $H_2SO_4$ if 1mole and of $Ag^+$ are deposited from silver nitrate solution?

Question

$\begin{array}{1 1}(a)\;4.2l&(b)\;6.2l\\(c)\;5.3l&(d)\;3.2l\end{array}$