The molar mass of unknown gas is 63.5 g/mol
calculation
let the unknown gas be represent by letter Y
The rate of effusion of a gas varies inversely with square root of molar mass
that is R(CH4)/ R(Y)= √[(M(Y)/M(CH4)]
= 47.8 ml/min/24.0ml/min= √[(Y/16g/mol)]
square both side to remove square root sign
=47.8²ml/min /24²ml/min= Y/16 g/mol
=2284.84ml/min/576ml/min=Y/16g/mol
multiply both side by 16
y =63.5 g/mol
