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 pressure acting on $A$ and $B$ will be

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

Answer 1

Answer: (A)

6 : 1

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