1. Gas Laws
Chapter 14

2. Kinetic Molecular Theory of Gases
No attraction/repulsion
Volume of particles is 0
Constant motion
Elastic collisions
Equal kinetic energy

3. Boyle’s Law
At constant temperature, pressure and volume are indirectly related.
P1V1 = P2V2
A gas system has an initial volume of 2.36L with the pressure unknown. When the volume changes to 2290mL the pressure is found to be 6390torr What was the initial pressure in atm?

4. Practice

5. Charles’s Law
At constant pressure, volume and temperature are directly related.
V1/T1 = V2/T2

6. What About Pressure and Temperature?
At constant volume, pressure and temperature are directly related
P1/T1 = P2/T2

7. Combined Gas Law P1V1/n1T1 = P2V2/n2T2
A closed gas system initially has pressure and temperature of 1.56atm and 629K with the volume unknown. If the same closed system has values of 195torr, 9940mL and 523K, what was the initial volume in L?

8. ASSIGNMENT
Practice Problems:
# 17-14

9. IDEAL GAS LAW PV=nRT R= 0.0821 L*atm/mol*K
Calculate the pressure in a 212 Liter tank containing 23.3 kg of argon gas at
25°C?

10. Ideal v. Real Gases They’re the same except at EXTREMELY LOW T
EXTREMELY HIGH P

11. Assignment
Section Assessment
# 25-30

12. Ideal Gas Law and Molar Mass
M=mRT/PV
How many grams of gas are present in a sample that has a molar mass of 70 g/mol and occupies a 2.00 L container at 117kPa and 35.1 oC?

13. Ideal Gas Law and Density
D=MP/RT
What is the density of a gas at STP that has a molar mass of 44.0 g/mol?

14. Dalton’s Law of Partial Pressure
Pressure and moles of gas are directly proportional.
Ptotal= P1 + P2 + P3 + …

15. Remember?
Gas Stoichiometry

16. Avogadro’s Principle
Equal volumes of gas at the same temperature and pressure have equal numbers of particles.
Translation:
1 mole = 22.4 L = 6.02 x 1023 gas particles
What is a mole? In Chemistry a mole is NOT an animal!!                               

17. Diffusion/Effusion
Diffusion- gases move toward areas of lower concentration
Effusion- gas escaping through tiny holes in container

18. Graham’s Law of Gaseous Effusion

19. TEST
30 MC Questions
5 problems requiring elegant solutions