Question

A gas mixture contains 79% nitrogen and 21% oxygen. If the total pressure is 1.02 atm, what are the partial pressures of each component?

Answer 1

We know that a gas mixture contains 79% nitrogen and 21% oxygen. We must find the partial pressures if the total pressure is 1.02 atm.

In order to find the partial pressures we must use the next equation

`\bar{P}=x_i\cdot P_(total)`

Where,

`\begin{gathered} x_i\text{ represents the }molar\text{ fraction} \\ P_(total)\text{ represents the total pressure} \end{gathered}`

1. For nitrogen which is in a 79%

`x_i=79\text{ \%}=(79)/(100)=0.79`

Now, replacing in the formula for the partial pressure

`\bar{P_N}=0.79\cdot1.02\text{atm}=0.8058\text{atm}`

2. For oxygen which is in a 21%

`x_i=21\text{ \%}=(21)/(100)=0.21`

Now, replacing in the formula for the partial pressure

`\bar{P}_O=0.21\cdot1.02atm=0.2142atm`

ANSWER:

- The partial pressure of the nitrogen is 0.8058 atm.

- The partial pressure of the oxygen is 0.2142 atm.