Question

Two seperate bulbs contain ideal gases $P$ and $Q$, respectively maintained at the same temperature. The density of gas $P$ is twice of that of the $Q$, and the molecular weight of the gas $P$ is half of that of the gas $Q$. The ratio of the pressure of gas $P$ to that of gas $Q$ is

• A. $2$
• B. $1/2$
• C. $4$
• D. $1/4$

Answer 1

The correct option is C $4$

$p=\frac{dRT}{M}$
As given in the question,
The density of gas $P$ is twice of that of the $Q$, and the molecular weight of the gas $P$ is half of that of the gas $Q$.
On substituting the values, in the above formula, we get
$\therefore \frac{p_P}{p_Q}=\frac{d_P}{d_Q}\times \frac{M_Q}{M_P}=2\times \frac{1}{\frac{1}{2}}=4$