1. GAS Laws chapter 10 p303 KMT Kinetic Molecular Theory 1. Gases consist of particles far apart. 2.Collisions between particles are elastic. elastic meaning = no net loss of KE 3.Gas particles are in constant, rapid, random motion 4.No forces of attraction or repulsion between gas particles. 5.Average KE of a gas depends on Temperature of gas.

2. Ideal Gases: an imaginary gas that perfectly fits all assumptions of KMT. (Noble gases) closest thing to it Real Gases: does not behave completely to the laws and theories of the KMT.

3. Need to know 4 items for understanding Gases Volume: liters and milliliters Temperature: Kelvin K K = 273 + o C convert 42 o C = 126 o C= 212 o C= Zero degrees Kelvin = absolute zero coldest temperature never reachable

4. Need to know 4 items for understanding Gases Volume: Temperature: # of moles or molecules avagadro’s number 6.022 x 10 23 molecules per mole 22.4 liters per mole @ STP STP === standard temperature pressure (O o C or 273K( (1atm)

5. P. 310 Pressure: atmatmosphere of pressure 1 atm = 760 mm Hg = 760 torr = 101.3 kpa Show overhead 49 Sea level pressure = 1 atm or 760mm Hg or 101.3 kpa STP === standard temperature pressure (O o C or 273K) (1atm) Average pressure in Denver Colorado is 0.083atm. Express in mm Hg and kpa

6. Boyles Law: keeping temperature same pressure up = volume down pressure down = volume up P 1 V 1 = P 2 V 2 When cap comes off …pressure goes down = volume goes up.

7. Video under pressure

8. Charles Law: keeping pressure same temperature up volume up temperature down volume down Balloon in freezer vs balloon next to heat Car tires in winter vs. tires in summer V 1 = V 2 T 1 T 2 Video wok/baloons

9. Gay-Lussac’s law : keeping volume same Temperature up =pressure up Temperature down =pressure down Throw hair spray can in fire P 1 P 2 T1T2T1T2 video crushing cans

10. What happens to the tire as you add pressure?

11. Why are weather balloons under inflated?

12. P. 321 Combined Gas Laws: all 3 put together P 1 V 1 =P 2 V 2 T1T2T1T2 Worksheet 10.33 1) If I initially have a gas at a pressure of 12 atm, a volume of 23 liters, and a temperature of 200k, and then I raise the pressure to 14 atm and increase the temperature to 300 K, what is the new volume of the gas? 3) A gas that has a volume of 28 liters, a temperature of 45c, and an unknown pressure has its volume increased to 34 liters, and its temperature decreased to 35c. If I measure the pressure after the change to be 2.0 atm, what was the original pressure of the gas?

13. Combined Gas Law P 1 V 1 = P 2 V 2 T 1 T 2

14. Ideal Gas Law Involves P,V,T & …number of moles of gas PV = nRT All units must be : P = atm V = liters T = Kelvin n = #of moles R =.0821 liters x atm moles x K R is a constant …….. Like pi is a constant 3.14 ws.11.21

15. Ws. 11.21 1. If I have 4 moles of a gas at a pressure of 5.6 atm and a volume of 12 L, what is the temperature? 2. If I have an unknown quantity of gas at a pressure of 1.2 atm, a volume of 31 liters, and a temperature of 87c, How many moles of gas do I have?

16. 3. If I contain 3 moles of gas in a container with a volume of 60 liters and at a temperature of 400K, what is the pressure inside the container?

17. Dalton’s Law of Partial Pressure Total pressure of a mixture of gases = sum of partial pressure of the component gases. P total = P 1 + P 2 + P 3 + P 4 … Overhead 48,50 Worksheet 10.38 problems 1,2,3

18. Diffusion & Effusion p. 351 KMT: 4- No significant forces of attraction or repulsion between gas particles So…..gas particles can flow easily past one another 3- Gas particles are in constant, rapid, random motion. They have KE. So…..random motion of gas particles causes the gas particles to evenly mix.

19. Effusion = movement of a material through a tiny opening in a container. “How fast a perfume comes out of a bottle” Diffusion = movement of one material through another material. Overhead 56 “Cooking cookies in the kitchen…others can smell it upstairs in the bedroom.” Rate of Diffusion depends on mass of particles ---Skinny people can run faster than fat people--- ---So can molecules---

20. Lighter molecule diffuse faster than heavy molecules @ STP overhead 54 Of the following molecules which would diffuse faster? l.Oxygen or Neon 2Sulfur dioxide or carbon dioxide 3.Chlorine gas or krypton gas

21. Ch. 11 Gas Lawsp. 333 Stoichiometry of gases 1 mole of oxygen has 6.022 x 10 23 molecules 1 mole of hydrogen has 6.022 x 10 23 molecules 1 mole of oxygen has a mass of 32 grams 1 mole of hydrogen has a mass of 2 grams (because diatomic) Avagadro has a standard molar volume for gases 1 mole of any gas has a volume of 22.4 liters Ws. 11.11

22. 1. A chemical reaction produces 0.068 mol oxygen gas. What volume in liters is occupied by this gas at STP? 2. A sample hydrogen gas occupies 14.1 L at STP. How many moles of the gas are present? 3. At STP a sample of neon gas occupies 550 cm 3. How many moles of neon gas does this represent?

23. Add more stoi problems