Question

50 ml of hydrogen diffuses out through a small hole from a vessel in 20 minutes, 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

Correct option is (b) 64 min

Rate of diffusion of gases is:

\(\frac{Rate_1}{Rate_2} = \frac{\sqrt{M_2}}{\sqrt{M_1}}\)

Rate of H₂ = \(\frac{50}{20} = 2.5\)

Rate of O₂ = \(\frac{40}{t}\)

\(\mathrm{\frac{Rate\ of\ H_2}{Rate \ of \ O_2}} = \frac{2.5}{40/t}= \sqrt{\frac{MO_2}{MH_2} } = \sqrt{\frac{32}2} = \sqrt {16} = 4\)

∴ 2.5t = 160

∴ t = \(\frac{160}{2.5}\) = 64 mins