High School

Suppose a balloon contains a mixture of helium, nitrogen, and oxygen gases. The pressure exerted by the mixture is 101.2 kPa. The partial pressure of helium is 80.1 kPa, and the partial pressure of nitrogen is 16.2 kPa.

What is the partial pressure of oxygen in the balloon?

Answer :

Answer:

4.9 kPa

Explanation:

Dalton's law of partial pressures states that the total pressure of a mixture of gases is the sum of the partial pressures of the individual gases.

In other words:
[tex]\displaystyle P_T = P_\text{O$_2$} + P_\text{N$_2$} + P_\text{He}[/tex]

The total pressure is 101.1 kPa. The partial pressure of He is 80.1 kPa. The partial pressure of N₂ is 16.2 kPa. Substitute and solve for O₂:


[tex]\displaystyle \begin{aligned} (101.2\text{ kPa}) & = P_\text{O$_2$} + (16.2\text{ kPa}) + (80.1\text{ kPa}) \\ \\ P_\text{O$_2$} & = 4.9\text{ kPa}\end{aligned}[/tex]

In conclusion, the partial pressure of oxygen in the balloon is 4.9 kPa.