Question

Equal moles of hydrogen and oxygen gases are placed in a container with a pin-hole through which both can escape. What fraction of the oxygen escapes in the time required for one-half of the hydrogen to escape ?

• A. 44565
• B. 44628
• C. 44563
• D. 44569

Answer 1

Answer: (D)

44569

Answer 2

$\frac{r_{O_2}}{r_{H_2}} = \sqrt{\frac{M_{H_2}}{M_{O_2}}}$
$\frac{\frac{n_{O_2}}{t}}{\frac{n_{H_2}}{t}} = \sqrt{\frac{2}{32}} = \sqrt{\frac{1}{16}} = \frac{1}{4}$
$\therefore \frac{n_{O_2}}{n_{H_2}} = \frac{1}{4}$
as $\frac{1}{2}$ moles of $H_2$ are diffused, moles of $O_2$ diffused in same time. $\frac{n_{O_2}}{1/2} = \frac{1}{4} \Rightarrow n_{O_2} = \frac{1}{8}$