Question

A vessel of volume $2000 cm ^{3}$ contains 0.1 mol of oxygen and 0.2 mol of carbon dioxide. If the temperature of the mixture is 300 K, find its pressure.

Answer 1

SOLUTION : We have $p=\frac{n R T}{V}$.

The pressure due to oxygen is $p_{1}=\frac{(0 \cdot 1 mol )\left(8.3 J K ^{-1} mol ^{-1}\right)(300 K )}{\left(2000 \times 10^{-6} m ^{-3}\right)}=1.25 \times 10^{5} Pa .$

Similarly, the pressure due to carbon dioxide is

$p_{2}=2.50 \times 10{ }^{5} Pa \text {. }$

The total pressure in the vessel is

$p =p_{1}+p_{2}$

$=(1 \cdot 25+2 \cdot 50) \times 10{ }^{5} Pa =3.75 \times 10{ }^{5} Pa .$