A `4 : 1` mixture of helium and methane contained in a vessel at 10 bar pressure. During a hole in the vessel, the gas mixture leaks out. The composition of the mixture effusing out initially is

Options

A. `8:1`
B. `1:8`
C. `1:4`
D. `4:1`

Answer

A

Explanation

Molar ratio of He and `CH_4=4:1`
`:.` partial pressure `P_(He)=4/5xx20=16` bar
partial pressure `P_(CH_4)=1/5xx20=4`
`:. P_(He):P_(CH_4)=16:4`
`because` time of diffusion is same base
`r_(He)/r_(CH_4)=n_(He)/n_(CH_4)=p_(He)/p_(CH_4)xxsqrt(M_(CH_4)/M_(He))=16/4xxsqrt(16/4)=4xx2=8:1`