The density of an unknown gas at `98^(@)C` and `0.974atm` is `2.5 xx10^(-3) g //ml`. What is the mol.wt. of gas ?

Explanation

Density `=2.5 xx 10^(-3) g //ml = 2.5 g//L`
`:. P M = rho R T `
`0.974 xx M = 2.5 xx 0.0821 xx371`
`rArr M = 78.18`