At identical temperature and pressure the rate of diffusion of hydrogen gas is `3sqrt3` times that of a hydrocarbon having molecular formula `C_(n)H_(2n-n)` What is the value of n ? .

Answer

4

Explanation

Given `r_(1) =3sqrt3`
`(r_(1))/(r_(2)) =sqrt((M_(2))/(M_(1))) :. (r_(1))/(r_(2))=sqrt((M_(2))/(M_(1))) =3sqrt3`
`or 3sqrt3=sqrt((M_(2))/(2)):. 27 = (M_(2))/(2)`
`:. M_(2) =54`
Now `12 xx n + 2 xx n-2 =54`
`n =4` .