High School

Select the correct answer.

A gas mixture containing oxygen, nitrogen, and carbon dioxide has a total pressure of 42.9 kPa. What is the partial pressure of carbon dioxide if the partial pressure of oxygen is 6.6 kPa and the partial pressure of nitrogen is 23.0 kPa?

A. 29.6 kPa
B. 19.9 kPa
C. 13.3 kPa
D. 36.3 kPa
E. 14.3 kPa

Answer :

To find the partial pressure of carbon dioxide in the gas mixture, we can use the concept of partial pressures, which states that the total pressure of a gas mixture is the sum of the partial pressures of each component in the mixture.

1. Start with the total pressure:
We know the total pressure of the gas mixture is 42.9 kPa.

2. Identify the known partial pressures:
The partial pressure of oxygen is 6.6 kPa.
The partial pressure of nitrogen is 23.0 kPa.

3. Determine the partial pressure of carbon dioxide:
According to Dalton's Law of Partial Pressures, the sum of the partial pressures of all gases in the mixture equals the total pressure. Therefore, we can find the partial pressure of carbon dioxide by subtracting the partial pressures of the known gases (oxygen and nitrogen) from the total pressure:

[tex]\[
\text{Partial pressure of carbon dioxide} = \text{Total pressure} - (\text{Partial pressure of oxygen} + \text{Partial pressure of nitrogen})
\][/tex]

Substituting the known values:

[tex]\[
\text{Partial pressure of carbon dioxide} = 42.9 \, \text{kPa} - (6.6 \, \text{kPa} + 23.0 \, \text{kPa})
\][/tex]

[tex]\[
\text{Partial pressure of carbon dioxide} = 42.9 \, \text{kPa} - 29.6 \, \text{kPa}
\][/tex]

[tex]\[
\text{Partial pressure of carbon dioxide} = 13.3 \, \text{kPa}
\][/tex]

Therefore, the partial pressure of carbon dioxide is 13.3 kPa. The correct answer is C. 13.3 kPa.