1. -Diffusion -Graham’s Law of Effusion -Dalton’s Law of Partial Pressures
Chemistry
Mrs. Coyle

2. Diffusion

3. Diffusion
The process in which particles of matter move from areas of high concentration to areas of low concentration.

4. Effusion
The passage of gases through a small hole or pores of a membrane.

5. Note
Gases of lower molar mass diffuse and effuse faster than gases of higher molar mass.

6. Graham’s Law of Effusion
________
va= √ (MMb ) vb MMa
v = rate of effusion MM= molar mass
-The rate of effusion of a gas is inversely proportional to the square root of its molar mass.

7. Example
Compare the rates of effusion of CO2 to oxygen gas.

8. Dalton’s Law of Partial Pressures

9. Dalton’s Law of Partial Pressures:
The total pressure in a gas mixture is the sum of the partial pressures of each individual gas.
Ptotal = Pgas 1 + Pgas 2 + Pgas 3 + …

10. Partial Pressure of a Gas:
The pressure that the gas would exert if it were the only gas present in the container.