1. Graham’s Law

2. Diffusion and Effusion
Diffusion – the gradual mixing of 2 or more gases due to their spontaneous, random motion
Effusion – molecules of gas confined in a container randomly pass through a tiny opening in the container

3. The rates of diffusion and effusion depend on the velocities of the gas molecules.
Velocity is determined by the equation
KE = ½mv2

4. Kinetic energy is dependent on temperature, meaning two different gases will have the same kinetic energy at the same temperature
½m1v12 = ½m2v22

5. Graham’s Law of Diffusion:
Rates of diffusion of gases at the same temp and pressure are inversely proportional to the square roots of their molar masses.
Rate means velocity
velocity = distance/time
Units = m/s

6. Compare the rates of diffusion of hydrogen and oxygen at the same temperature and pressure.
rateH2 √MO √32.00g/mol
rateO2 √MH √2.02g/mol
Hydrogen diffuses 3.98 times faster than oxygen
3.98

7. Lighter gases travel faster
Heavier gases travel slower
…therefore, lighter gases travel farther in the same amount of time.

8. Make a kids book about gas laws!
For each Gas Law (all 8 now)
- Name of law - Formula - Explain what law means (in words) - Way to remember law - Example of law (using real life examples) - Drawing