Question

If rate of diffusion of $A$ is 5 times that of $B$, what will be the density ratio of $A$ and $B$?

• A. $\frac{1}{25}$
• B. $\frac{1}{5}$
• C. $25$
• D. $5$

Answer 1

The correct option is A $\frac{1}{25}$

The rate of diffusion of a gas is inversely proportional to the square root of its density.
$\frac{r_A}{r_B}=\sqrt{\frac{d_B}{d_A}}$
The rate of diffusion of A is 5 times that of B.
${\left(\frac{5r}{r}\right)}^2=\frac{d_B}{d_A}$
The density ratio of $A$ and $B$
$\frac{d_A}{d_B}=\frac{1}{25}$