Question

A certain gas diffuses four times as quickly as oxygen. The molecular weight of the gas is

• A. 2
• B. 1
• C. 16
• D. 1 .5.

Answer 1

Answer: (A)

rate of diffusion $\propto \frac{1}{\sqrt{M}}$
M = Molecular mass
$\Rightarrow \frac{r_x}{r_{o_2}}=4=\sqrt{\frac{M_{o_2}}{M_x}}$
$r_x$ =rate of diffusion of x (gas)
$M_x$ =Molecular mass of x
$\Rightarrow \frac{r_x}{r_{o_2}}=4=\sqrt{\frac{M{O}_2}{M_x}}$
$\Rightarrow 16=\frac{32}{M_x}$
$\Rightarrow M_x=2$