5. can be compressed exert pressure on whatever surrounds them expand into whatever volume is available easily diffuse into one another can be described in terms of temperature, pressure, volume and amount

6. gases exert a pressure on the walls of their container. P F (N) A (m 2 )  SI unit: 1 N/m 2 = 1 Pascal (Pa) pressure is defined as force per unit area:

8. The atmospheric pressure can be measured using a barometer.

9. 760 mm Hg = 1 atm= 101 kPa Standard atmospheric pressure supports a column of mercury about 760 mm high.

11. If the barometer reads 753.3 mm Hg, what is the atmospheric pressure in atm and kPa? = 0.9912 atm 753.3 mm Hg 760 mm Hg 1 atm = 100.1 kPa 101 kPa 753.3 mm Hg 760 mm Hg

12. Lord Kelvin proposed an absolute temperature scale defined by: T (K) = T (C) + 273.15

14. Convert the following temperatures into Kelvin or celcius: 45 o C → 318.15 K 207 o C → 480.15 K - 48 o C → 225.15 K 100 K → - 173.15 o C

15. Pressure Conversions: 1. 0.875 atm to mmHg 2. 745.0 mmHg to atm 3. 0.955 atm to kPa 4. 98.35 kPa to atm 5. 740.0 mmHg to kPa 6. 99.25 kPa to mmHg Temperature Conversions: 1. 250 Kelvin to Celsius 2. 339 Kelvin to Celsius 3. 17 Celsius to Kelvin 4. 55 Celsius to Kelvin 5. -200 Celsius to Kelvin 665 mm Hg 0.9803 atm 96.5 kPa 0.9738 atm 98.34 kPa 746.8 mm Hg

16. In order to compare two gases, we choose a standard temperature and pressure: STP: standard temperature and pressure → 273.15 K and 101.325 (data booklet) → one mole of gas has a volume of 22.4 L SATP: standard ambient temperature and pressure → 298.15 K and 100.00 kPa → one mole of gas has a volume of 24.8 L

18. Graph the following information Pressure (KPa) Volume (L) 1005.00 1104.55 1204.16 1303.85 1403.57 K (VP) 500 500.5 499.2 500.5 499.8 P 1 V 1 = K = P 2 V 2 Is there a relationship between pressure and volume? volume pressure

20. For a given mass of gas at constant temperature, the volume of a gas varies inversely with pressure. P 1 V 1 = P 2 V 2

21. Graph the following data Temperature (K)Volume (L) 298 5.00 323 5.42 348 5.84 373 6.26 398 6.68 K (V/T) 0.0167 0.0168 V 1 /T 1 = K = V 2 /T 2 temperature volume Is there a relationship between pressure and volume?

22. Charles discovered that volume is directly proportional to its Kelvin temperature if a fixed mass remains under constant pressure. V 1 V 2 T 1 T 2 =

24. V versus T for different gases

25. The pressure of a gas is directly proportional to the Kelvin temperature, providing the volume and mass remain constant. P1P1 P2P2 = T1T1 T2T2 Joseph Louis Gay-Lussac and Jean-Baptistse Biot in their balloon on 24 August 1804

26. V 1 P 1 = V 2 P 2 T 1 T 2

27. In 1811, Avogadro proposed that equal volumes of gases at the same temperature and pressure contain equal numbers of molecules. It follows that the volume of a gas at constant temperature and pressure is proportional to number of moles. V 1 V 2 n 1 n 2 =

28. The relationship between volume V and number of moles n.

29. The Ideal Gas Equation Combining the gas laws gives: atm R L molK    008206. where R is called the Gas constant: PV = nRT

30. In order to compare two gases, we choose a standard temperature and pressure: STP: 0  C and 1 atm What is the volume of a mole of gas at STP? 1 mol  273.15 K 1 atm = = 22.4 L

32. If 6.45 grams of water are decomposed, how many liters of oxygen will be produced at STP? 2 H 2 O (g)  2 H 2(g) + O 2(g) 6.45 g H 2 O 18.02 g H 2 O 1 mol H 2 O 2 mol H 2 O 1 mol O 2 22.4 L O 2

33. How many liters of CH 4 at STP are required to completely react with 17.5 L of O 2 ? CH 4(g) + 2 O 2(g)  CO 2(g) + 2 H 2 O (g) 17.5 L O 2 22.4 L O 2 1 mol O 2 2 mol O 2 1 mol CH 4 22.4 L CH 4 = 8.75 L CH 4 22.4 L O 2 1 mol O 2 1 mol CH 4 22.4 L CH 4

34. Equal volumes of gas, at the same temperature and pressure contain the same number of particles. Moles are numbers of particles You can treat reactions as if they happen liters at a time, as long as you keep the temperature and pressure the same.

35. How many liters of H 2 O at STP are produced by completely burning 17.5 L of CH 4 ? CH 4(g) + 2 O 2(g)  CO 2(g) + 2 H 2 O (g) 17.5 L CH 4 1 mol CH 4 2 mol H 2 O = 35.0 L H 2 O

37. 2 NaN 3(s)  2Na (s) + 3N 2(g) Secondary reaction: 10 Na + 2 KNO 3  K 2 O + 5 Na 2 O + N 2(g)

38. To measure the amount of gas produced in a reaction, it is often collected over water. MgO (s)  Mg (s) + O 2(g)