At `0^@C` the density of a certain oxide of a gas at 2bar is same as that of dinitrogen at 5 bar, What is the molecular mass of the oxide?

Explanation

Calculation of density of `N_2` at 5 bar and `0^@C`
`d=(pM)/(RT)=(5b ar times28g mol^-1)/(0.0831 L b ar k^-1 mol^-1times273.15k)`
calculation of molar mass of gaseous oxide
`M=(dRT)/P`
`=(6.188gL^-1times0.0831L ba r k^-1mol^-1times273.15k)/2`
=`70.0g mol^-1`