The vapour density of $\mathrm{N}_{2} \mathrm{O}_{4}$ is 46 . When heated in a vessel, at constant p

Question

The vapour density of $\mathrm{N}_{2} \mathrm{O}_{4}$ is 46 . When heated in a vessel, at constant pressure, vapour density decreases to 24.5. The % dissociation of $\mathrm{N}_{2} \mathrm{O}_{4}$ at the final temperature\

Professor PC Thomas Classes · Answer

$\mathrm{N}_{2} \mathrm{O}_{4} ightarrow 2 \mathrm{NO}_{2}$\ $\begin{array}{lll}1-\alpha & 2 \alpha & 	ext { Total } 1+\alpha\end{array}$\ $\mathrm{i}=\frac{	ext { normal molwt }}{	ext { observed } \mathrm{mol} \mathrm{wt}}=\frac{92}{49}=1.87=\frac{1+\alpha}{1}$\ $1+\alpha=1.87$ ie; $\alpha=0.87$\ % dissociated = 87%