Question

At $298$ K, equal volumes of $S{O}_2,C{H}_4$ and $O_2$ are mixed in empty container. The total pressure exerted is $2.1$ atm. The partial pressure of $C{H}_4$ in mixture is :

• A. $0.6atm$
• B. $1.2atm$
• C. $2.4atm$
• D. $3.6atm$

Answer 1

The correct option is B $1.2atm$

Let the wt. of each gas mixed $=xg$

$\therefore$ moles of $S{O}_2=\frac{x}{64}$

Moles of $C{H}_4=\frac{x}{16}$

Moles of $O_2=\frac{x}{32}$

Total number of moles of the three gases
$\frac{x}{64}+\frac{x}{16}+\frac{x}{32}=\frac{7x}{64}$.

Partial pressure exerted by a gas in the mixture of non-reacting gases $\left(p\right)$ is given by

$p=\frac{\text{moles of that gas}}{\text{total moles}}\times \text{Total pressure}$

$\therefore p_{C{H}_4}=\frac{x}{16}\times \frac{64}{7x}\times 2.1=1.2atm$