Question

Under similar conditions which of the following gases to diffuse four times as quickly as oxygen?

• A. $He$
• B. $H_2$
• C. $N_2$
• D. $D_2$

Answer 1

Answer: (B)

$H_2$

Using graham's law of diffusion :

$\frac{r_{gas}}{r_{O_2}}=\sqrt{\frac{M_{O_2}}{M_{gas}}}$

$4=\sqrt{\frac{32}{M_{gas}}}$ or $16=\frac{32}{M_{gas}}$

or $M_{gas}=\frac{32}{16}=2$, i.e., $H_2$

Hence, the correct option is B.