40 mL of a mixture of hydrogen, `CH_(4)andN_(2)` was exploded with 10 mL of oxygen On cooling, the gases occupied 36.5 mL. After treatment with KOH, the volume reduced by 3 mL and again on treatment with alkaline pyrogallol, the volume further decreaed by 1.5 mL. Determine the composition of the mixture.

Explanation

`H_(2):12.50%,CH_(4):7.50%,N_(2):80%`