1. KMT and Graham’s Law

2. Molecular Speed Of A Gas Depends on the mass of the gas molecules and the temperature they are at R is in different units and has a different value ( R=8.3145) M is molar mass in kg/mole

3. Example Find the speed of hydrogen gas at 25 o C. Find the speed of oxygen gas at 25 o C.

4. Effusion Gas escapes through tiny holes when a pressure difference is present

5. Diffusion Gases will mix uniformly

6. Graham’s Law Rate of both effusion and diffusion is inversely related to the square root of their weights Shows the relationship between rate and molecular weight

7. Example If an unknown gas effuses at a rate that is only.468 times that of oxygen at the same temperature, what is its molecular weight?

8. Ideal vs. Real Gas Behavior Ideal gases follow all of the gas laws outlined No gas is totally ideal, but at low pressures and/or high temperatures most come close Gases will deviate significantly from ideal at high pressures and/or low temperatures - particles become closer together and intermolecular forces between significant