Question

At `0^(@)C` , the density of a gaseous oxide at `2` bar is the same as that of dinitrogen at `5` bar. The molar mass of the oxide is
A. `60 g mol^(-1)`
B. `50 g mol^(-1)`
C. `70 g mol^(-1)`
D. `30 g mol^(-1)`

Answer 1

Correct Answer - C
According to the ideal gas law,
`pM = dRT`
At the same temperature `(T)` and for the same density `(d) ,pM` becomes a constant. Thus,
`p_(o x i de)M_(o x i de) = p_(N_(2))M_(N_(2))`
or `M_(Ox i de) = p_(N_(2)) M_(N_(2))//p_(o x ide)`
`= ((5 ba r) (28 g mol^(-1)))/((2 ba r))`
`= 70 g mol^(-1)`