Question

A compound exists in the gaseous phase both as monomer ($A$) and dimer $\left(A_2\right)$ . The atomic mass of $A$ is 48 and molecular mass of $A_2$ is 96. In an experiment 96 $g$ of the compound was confined in a vessel of volume 33.6 $L$ and heated to ${273}^{\circ }C$. The pressure developed if the compound exists as dimer to the extent of 50% by weight under these conditions will be :

• A. 1 $atm$
• B. 2 $atm$
• C. 1.5 $atm$
• D. 4 $atm$

Answer 1

The correct option is B 2 $atm$

We know, $PV=nRT$

$PV=(n_1+n_2)RT$

$n_1=\frac{48}{96},n_2=\frac{48}{48}$

$P=\frac{(0.5+1)\times 0.082\times 546}{33.6}=1.99atm$

So, the correct option is $B$