Question

A gas A diffuses 5 times faster than gas B. Density of A compared with B is

(a) 5

(b) 25

(c) 1/5

(d) 1/25

Answer 1

Correct option is (d) 1/25

r_A = 5r_B, the rate of diffusion of a gas is inversely proportional to the square root of its' density.

\(\frac{r_A}{r_B} = \sqrt{\frac{d_B}{d_A}}\)

\(\frac{5r_B}{r_B}=\sqrt{\frac{d_B}{d_A}}\)

\(\Rightarrow \frac{d_B}{d_A} = \frac{25}1\)

\(\Rightarrow \frac{d_A}{d_B} = \frac1{25}\)