The reaction $2N_2O_5(g) \to 4NO_2(g) +O_2(g)$ follows first order kinetics . The pressure of a vessel containing only $N_2O_5$ was found to increase from $50 \;mm$ Hg to $87.5\;mm$ Hg in 30 min. The pressure exerted by the gas after 60 min will be (Assume temperature remains constant ) :

Question

$\begin{array}{1 1} 106.25\;mm\;Hg \\ 116.25\;mm\;Hg \\ 125\;mm\;Hg \\ 150\;mm\;Hg \end{array} $