Question

Certain volume of $He$ gas takes $10$ sec for its diffusion, how much time will be taken by $C{H}_4$ gas to disffuse its same volume under identical conditions ?

• A. $5$ sec
• B. $10$ sec
• C. $20$ sec
• D. $40$ sec

Answer 1

Answer: (A)

$5$ sec

$Timetakenfordiffusion\propto \frac{1}{\sqrt{\text{Molecular wt.}}}$

$\therefore \frac{10}{t_{C{H}_4}}=\sqrt{\frac{16}{4}}$

$\therefore t_{C{H}_4}=\frac{10}{2}=5sec$