Question

$50ml$ of $H_2$ takes $10$ minute to diffuse out of a vessel. The time taken to diffuse $40ml{O}_2$ under the similar conditions would be:

• A. $32$ minute
• B. $30$ minute
• C. $35$ minute
• D. $28$ minute

Answer 1

Answer: (A)

$32$ minute

By grahams law,

The rate of diffusion of gases is inversly proportional to square root of molar mass.

$\frac{R_{H_2}}{R_{O_2}}=\frac{\frac{V_{H_2}}{t_{H_2}}}{\frac{V_{O_2}}{t_{O_2}}}=\sqrt{\frac{M_{O_2}}{M_{H_2}}}$

$\Rightarrow \frac{\frac{50}{10}}{\frac{40}{x}}=\sqrt{\frac{32}{2}}$

$\Rightarrow \frac{5x}{40}=4$

$\Rightarrow x=160/5=32$ minutes

$\therefore$ Ans :- Option A.