A 4 : 1 molar mixture of `He` and `CH_(4)` is contained in vessel at 20 per pressure. Due to a hole in the vessel the gas mixture leakes out. What is the compostion of mixture effusing out initially.

Answer

`8 : 1`

Explanation

Partial pressure ratio of `He " and " CH_(4) " is " 16 : 4`
For diffusion `(r_(He))/(r_(CH_(4))) = sqrt((M_(CH_(4)))/(M_(He))) xx (p_(He))/(p_(CH_(4)))`
`(n_(He))/(n_(CH_(4))) = sqrt((16)/(4)) xx (16)/(4) = 8`
i.e., mole ratio of diffusion for He and `CH_(4) " is " 8 : 1`