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

Answer

70 g/mol

Explanation

Density (d) of the substance at temperature (T) can be given by the expression,
d= `(Mp)/(RT)`
Now, density of oxide `(d_(1))` is given by,
`d_(1)=(M_(1)p_(1))/(RT)`
Whwew, `M_(1)` and `p_(1)` are the mass and pressure of the oxide respectively. Density of dinitrogen gas `(d_(2))` is given by,
`d_(2)=(M_(2)p_(2))/(RT)`
Where, `M_(2)` and `p_(2)` are the mass and pressure of the oxide respectively. According to the given question,
`d_(1)=d_(2)`
`therefore M_(1)p_(1)=M_(2)p_(2)`
`p_(1)` = 2 bar
`p_(2)` = 5 bar
Molecular mass of nitrogee, `M_(2)=28g//mol`
`Now,M_(1)=(M_(2)p_(2))/p_(1)`
`=(28xx5)/2`
= 70 g/mol
Hence, the moleculare mass of the oxide is 70 g/mol.