Question

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]

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

Answer 1

The correct option is A 15 bar

According to Dalton’s law
$P_{N_2}={\chi }_{N_2}{P}_{\text{total}}$
$P_{N_2}=\frac{\frac{7}{28}}{(\frac{8}{40}+\frac{7}{28})}\times 27$
$P_{N_2}=(\frac{0.25}{0.2+0.25}\times 27)$
$P_{N_2}=15\text{bar}$