Question

50 ml of hydrogen diffuses out through a small hole from a vessel in 20 minutes. The time needed for 40 ml of oxygen to diffuse out is........

• A. 12 min
• B. 64 min
• C. 8 min
• D. 32 min

Answer 1

The correct option is B

64 min

If 40 ml $O_2$ will diffuse in t min, then, $r_{O_2}$= $\frac{40}{t}$

$r_{H_2}$= $\frac{50}{20}$ $\Rightarrow$ $r_{O_2}$ = $r_{H_2}$ $\sqrt{\frac{M_{O_2}}{M_{H_2}}}$ $\Rightarrow$ $\frac{50}{20}$ $\sqrt{\frac{2}{32}}$ = $\frac{50}{20}\times \frac{1}{4}$

$\frac{40}{t}$= $\frac{50}{20}$ $\Rightarrow$ t =$\frac{40\times 80}{50}$ (40*80)/50 $\Rightarrow$ 64 min.