Question

A mixture of hydrogen gas and oxygen gas exerts a total pressure of 1.5 atm on the walls of its container. If the partial pressure of hydrogen is 1 atm, find the mole fraction of oxygen in the mixture.

• A. 0.33
• B. 0.5
• C. 0.66
• D. 0.25

Answer 1

The correct option is A 0.33

Given, $P_{hydrogen}$ = 1 atm, $P_{total}$ = 1.5 atm

Applying Dalton’s law formula, $P_{total}=P_{hydrogen}+P_{oxygen}$

Therefore, $P_{oxygen}$ = 0.5 atm

Now, the mole fraction of oxygen, $X_{oxygen}=\frac{P_{oxygen}}{P_{total}}=\frac{0.5}{1.5}=0.33$

Therefore, the mole fraction of oxygen in the mixture is 0.33