Question

$50ml$ of hydrogen diffuses out through a small hole from a vessel in $20$ minutes. Calculate the time (in minutes) needed for $40ml$ of oxygen to diffuse out

Answer 1

Answer: 64

If $40ml{O}_2$ will diffuse in t min. then. $r_{O_2}=\frac{\text{40}}{t}$

$r_{H_2}=\frac{\text{50}}{\text{20}}$

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

$\frac{\text{40}}{t}=\frac{\text{50}}{\text{80}}\therefore t=\frac{\text{40}\times \text{80}}{\text{50}}=\text{64 }min.$