A mixture of `N_(2)` and Ar gases in a cylinder contains 7 g of `N_(2)` and 8 g of Ar. If the total pressure of the mixture of the gases in the cylinder is 27 bar, the partial pressure of `N_(2)` is
[Use atomic masses (in g `mol^(-1)`) : N = 14, Ar = 40]

Options

A. 9 bar
B. 12 bar
C. 15 bar
D. 18 bar

Answer

C

Explanation

Number of moles of `N_(2)=7/28=0.25` mol
Number of moles of Ar =`8/40=0.2` mol
Mole fraction of `N_(2)=(0.25)/(0.25+0.2)=(0.25)/(0.45)=0.55`
Partial pressure of `N_(2)` gas = mole fraction `times` total pressure
`" "=0.55 times 27=14.85 approx 15` bar