Question

You collect a sample of gases from an indoor pool area. The sample contains air and water vapor. The total pressure is 100.18 kilopascals, and the partial pressure of the water vapor is 3.36 kilopascals. What is the partial pressure of the air in the sample?
A. 29.8 kPa
B. 51.77 kPa
C. 96.82 kPa
D. 103.54 kPa
E. 337 kPa

Answer 1

C. 96.82 kPa because to find the amount of pressure the air is causing you need to subtract the amount of pressure the water vapor is causing because the only two gasses making up the air in the pool area are air and water vapor.

Answer 2

Answer: C. 96.82 kPa

Explanation: According to Dalton's law, the total pressure of a mixture of gases is the sum of individual pressures exerted by the constituent gases.

$p_{total}=p_A+p_B$

Thus $p_{total}=p_{/text {water vapor}}+p_{air}$

Given: $p_{total}=100.18 kPa$

$p_{/text {water vapor}}=3.36kPa$

$p_{air}= ?kPa$

Thus $100.18kPa=3.36kPa+p_{air}$

$p_{air}=96.82kPa$