Question

The relative rate of diffusion of a gas (mol. wt. = 98) as compared to hydrogen will be :

• A. $1/7$
• B. $1/5$
• C. $1/4$
• D. $1$

Answer 1

The correct option is A $1/7$

The relative rate of diffusion of a gas (mol wt. = 98) as compared to hydrogen will be $1/7$.
The rate of diffusion is inversely proportional to the square root of molar mass.
$\frac{r}{r^{\prime }}=\sqrt{\frac{M^{\prime }}{M}}$
here, $r$ and $r^{\prime }$ are the rates of diffusion and $M$ and $M^{\prime }$ are the molar masses of gases $A$ and $B$ respectively.
$\frac{r}{r^{\prime }}=\sqrt{\frac{2}{98}}=\frac{1}{7}$