Question

Gas $A$ diffuses twice as quickly as the gas $B$. If the molecular weight of $B$ is 32, the molecular weight of $A$ is:

• A. 32
• B. 16
• C. 4
• D. 8

Answer 1

The correct option is D 8

$\frac{r_A}{r_B}=\sqrt{\frac{M_B}{M_A}}$

$\frac{2r_B}{r_B}=\sqrt{\frac{32}{M_A}}$

$M_A=8$

Hence, the correct answer is option $\text{D}$.