Question

A mixture of argon, oxygen, and nitrogen has a total pressure of 725 mmHg. Thepartial pressure of nitrogen is 148 mmHg. The partial pressure of argon is 218mmHg. What is the partial pressure of oxygen in atm?

Answer 1

The partial pressure of oxygen in atm = 0.472 atm

Step-by-step explanation

Dalton’s Law of Partial Pressure states that the total pressure exerted by a mixture of gases is equal to the sum of the partial pressure of the individual gases present in the container.

`P_t=P_1+P_2+P_3+....+P_n`

Given:

The total pressure, Pt = 725 mmHg,

the partial pressure of nitrogen, P₁ = 148 mmHg, and

the partial pressure of argon, P₂ = 218 mmHg

What to find:

The partial pressure of oxygen, P₃ in atm.

Step-by-step solution:

`\begin{gathered} \begin{equation*} P_t=P_1+P_2+P_3 \end{equation*} \\ \\ 725mmHg=148mmHg+218mmHg+P_3 \\ \\ 725mmHg=366mmHg+P_3 \\ \\ P_3=725mmHg-366mmHg \\ \\ P_3=359\text{ }mmHg \end{gathered}`

The final step is to convert the partial pressure of 359 mmHg oxygen to atm.

So 359 mmHg will be (359 mmHg x 1 atm)/(760 mmHg) = 0.472 atm

Hence, the partial pressure of oxygen in atm = 0.472 atm