Homework Check (The Ideal Gas Law)

1. If I contain 3 moles of gas in a container with a volume of 60 L at a temperature of 400 K, what is the pressure inside the container?

2. If I have 7.7 moles of gas at a pressure of 0.09 atm and a temperature of 56 ⁰C, what is the volume of the container that the gas is in?

3. If I have 17 moles of gas at a temperature of 67 ⁰C, and a volume of 88.89 L, what is the pressure of the gas?

Dalton’s Law of Partial PressuresFor Mixture of Gases

PH2 = 2.4 atm PHe = 6.0 atm Ptotal = 2.4 + 6.0 = 8.4 atm

Dalton’s Law of Partial Pressures

Total pressure of a mixture of gases is the sum of the partial pressures of each of the gases in the mixture. The partial pressure of a gas depends on the number of moles of gas (n), the size of the container (V), and the temperature of the mixture (T). It does not depend on the identity of the gas.

What is the pressure of Argon gas in the second container?

2 atm + ? atm + 3 atm = 6 atm

N2Ar O2 Air

Barometer

Example1. What is the partial pressure of water vapor (H2O gas) in

an air sample when the total pressure is 1.00 atm, the partial pressure of Nitrogen (N2) is 0.79 atm, the partial pressure of Oxygen (O2) is 0.20 atm, and the partial pressure of all other gases in air is 0.0044 atm?

Practice! (on a separate piece of paper)

1. What is the total gas pressure in a sealed flask that contains Oxygen gas (O2) at a partial pressure of 0.41 atm and water vapor (H2O gas) at a partial pressure of 0.58 atm?

2. A mixture of Oxygen (O2), Carbon Dioxide (CO2), and Nitrogen (N2) has a total pressure of 0.97 atm. What is the partial pressure of O2 if the partial pressure of CO2 is 0.70 atm and the partial pressure of N2 is 0.12 atm?