Question

$50ml$ of hydrogen diffuses out through a small hole from a vessel in $20$ minutes, the time needed for $40ml$ of oxygen to diffuse out is:

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

Answer 1

The correct option is B $64min$

$Rate\left(H_2\right)=\frac{50}{20}=2.5$

${Rate(O}_2)=\frac{40}{t}$

$\frac{r_{H_2}}{r_{O_2}}=\frac{2.5t}{40}=\sqrt{\frac{M{O}_2}{M{H}_2}}=\sqrt{\frac{32}{2}}=4$

$\Rightarrow 2.5t=160$

$t=64min$