1. Gas Variables

2. Pressure 1. Caused by collisions between molecules and the walls of container. 2. Force per unit area; changing force of collisions or area changes pressure. 3. Units: 1 atm = 101.3 kPa = 760 mm Hg (torr) = 14.7 lbs/in 2 (psi)

3. Volume 1. Determined by space between molecules. Molecules themselves are assumed to have no volume. 2. As molecules bounce more vigorously, spacing widens. 3. Units: mL, liters

4. Temperature 1. Directly proportional to average kinetic energy of molecules: 12mv 2 = cT 2. Must be Kelvin for gas law calculations.

5. Amount 1. Perhaps surprisingly, number, not mass, of molecules determines gas properties. 2. Moles.

6. Avogadros Law: Volume and Number of moles are directly proportional. Minor Gas Laws

7. Avogadros Law: Volume and Number of moles are directly proportional. Minor Gas Laws

8. Avogadros Law: Volume and Number of moles are directly proportional. Minor Gas Laws

9. Boyles Law: Pressure and Volume are inversely proportional. Minor Gas Laws

10. Boyles Law: Pressure and Volume are inversely proportional. Minor Gas Laws

11. Charles Law: Volume and Temperature are directly proportional. Minor Gas Laws

12. Charles Law: Volume and Temperature are directly proportional. Minor Gas Laws

13. Daltons Law: Pressure and Number of moles are directly proportional. Minor Gas Laws

14. Gay-Lussacs Law: Pressure and Temperature are directly proportional. Minor Gas Laws

15. In summary… Minor Gas Laws

16. The five minor gas laws can be combined by focusing on the one law that is different… Combining the Gas Laws Boyles Law P1V1=P 2 V2 Avogadros Law Charles Law Daltons Law Gay- Lussacs Law

17. This is called the COMBINED GAS LAW. Combining the Gas Laws

18. OR, if only one set of data exists, a single useful equation results… The Ideal Gas Laws

19. When the five minor gas laws are combined, a single useful equation results… The Ideal Gas Laws In this equation, P should be in atm V should be in liters n should be in moles T should be in Kelvin R is the gas constant… 0.0821

20. The Ideal Gas Laws