Question

Air is about 78.0% nitrogen molecules and 21.0% oxygen molecules. Several other gases make up the remaining 1% of air molecules.

Part A
What is the partial pressure of nitrogen in air at atmospheric pressure (1 atm)? Assume ideal behavior.
Express your answer to three significant figures and include the appropriate units.
Part B
This part will be visible after you complete previous part(s).
Part C
What is the partial pressure of oxygen in air at atmospheric pressure (1 atm)? Assume ideal behavior.
Express your answer to two decimal places and include the appropriate units.

Answer 1

For A: The partial pressure of nitrogen in air is 0.780 atm

For C: The partial pressure of oxygen in air is 0.210 atm

Step-by-step explanation:

Raoult's law is the law that is used to calculate the partial pressure of the individual gases present in the mixture.

The equation for Raoult's law is given as:

`p_A=\chi_A* p_T` .....(1)

where,

`p_A` = partial pressure of component A in the mixture

`p_T` = total partial pressure of the mixture

`\chi_A` = mole fraction of A

• For A:

We are given:

% composition of nitrogen in air = 78.0 %

`\chi_(N_2)=0.780\\\\p_T=1atm`

Putting values in equation 1, we get:

`p_(N_2)=0.780* 1atm\\\\p_(N_2)=0.780atm`

Hence, the partial pressure of nitrogen in air is 0.780 atm

• For C:

We are given:

% composition of oxygen in air = 21.0 %

`\chi_(O_2)=0.210\\\\p_T=1atm`

Putting values in equation 1, we get:

`p_(O_2)=0.210* 1atm\\\\p_(O_2)=0.210atm`

Hence, the partial pressure of oxygen in air is 0.210 atm