Question

A mixture of $N_2$ and $O_2$ gases in a cylinder contains $7\text{g}$ of $N_2$ and $8\text{g}$ of $O_2$. If the total pressure of the mixture of the gases in the cylinder is $12\text{bar}$, then the partial pressure of $N_2$ is:
[Use atomic masses, $N=14\text{u},O=16\text{u}$]

• A. $12\text{bar}$
• B. $6\text{bar}$
• C. $4\text{bar}$
• D. $9\text{bar}$

Answer 1

The correct option is B $6\text{bar}$

$p_{{}_{N_2}}=\left({\chi }_{N_2}\right)P_{\text{Total}}=\left(\frac{\frac{7}{28}}{\frac{7}{28}+\frac{8}{32}}\right)\times 12$
$=\frac{\frac{1}{4}}{\frac{1}{2}}\times 12=6\text{bar}$