Question

A closed vessel contains $8g$ of oxygen and $7g$ of $N_2$ Total pressure is 10 atm at a given temperature. If now oxygen is absorbed by introducing a suitable absorbent, the pressure of the remaining gas will be

• A. 2
• B. 10
• C. 4
• D. 5

Answer 1

Answer: (D)

$P_{\text{mix }}=P_1+P_2$
$P_{\text{mix }}=\frac{n_{1}RT}{V}+\frac{n_{2}RT}{V}$
$10=\frac{8RT}{32V}+\frac{7RT}{28V}$
$\Rightarrow 10=\frac{RT}{2V}$
$\Rightarrow \frac{RT}{V}=20$
If $O_2$ absorbed pressure by $N_2$
$P_{N_2}=\frac{7}{28}\frac{RT}{V}\left(\frac{2}{2}\right)$
$=\frac{10}{2}=5$ atm