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

Explanation

Equation expressing the relation between density (d), pressure (P), absolute temperature (T) and molar mass (M) of a gas is `d=(PV)/(RT)`
Density of the oxide of the gas, `d_(1)=(2xxM)/(Rx273)` [M=molecular mass of the oxide]
Density of `N_(2)` gas, `d_(2)=(5xx28)/(Rxx273)` [molecular mass of `N_(2)=28g*mol^(-1)`]
It is mentioned that under the given conditions, `d_(1)=d_(2)`
`therefore (2xxM)/(Rxx273)=(5xx28)/(Rxx273) or, M=70`
Therefore, the molecular mass of the oxide is `70g*mol^(-1)`.