Question

The density of a gas $A$ is twice that of a gas $B$ at the same temperature. The molecular mass of gas $B$ is thrice that of $A$. The ratio of the pressures acting on $A$ and $B$ will be

• A. $6:1$
• B. $7:8$
• C. $2:5$
• D. $1:4$

Answer 1

The correct option is A $6:1$

$Pm=dRT$
$\frac{P_A{m}_A}{P_B{m}_B}=\frac{d_{A}RT}{d_{B}RT}$
$\frac{P_A}{P_B}\times \frac{1}{3}=2$
$P_A:P_B=6:1$