Question

A cylinder is filled with a gaseous mixture containing equal masses of $CO$ and $N_2$. The ratio of their partial pressure is:

• A. $P_{N_2}=P_{CO}$
• B. $P_{CO}=0.875P_{N_2}$
• C. $P_{CO}=2P_{N_2}$
• D. $P_{CO}=\frac{1}{2}{P}_{N_2}$

Answer 1

Answer: (A)

$P_{N_2}=P_{CO}$

Given : Equal masses of $CO$ and $N_2$.

We know that

$Partialpressure=\text{Mole fraction}\times \text{Total pressure}$

Since masses are equal and molar masses are also equal

$X_{CO}=\frac{1}{2}$ and $X_{N_2}=\frac{1}{2}$

$\frac{P_{N_2}}{P_{CO}}=\frac{X_{N_2}\times P}{X_{CO}\times P}=\frac{\frac{1}{2}}{\frac{1}{2}}=1$

Hence , $P_{N_2}=P_{CO}$