2. May 7, 2012 HONORS CHEMISTRY

3. Brain Teaser Turn in Titration Lab Describe the characteristics or properties of solid, liquid and gases

4. Agenda Brain Teaser Unit 9 Acid/Base Test Result Notes: Introduction to Gases and Gas Laws Homework  Charles and Boyles Law Worksheet

5. Introduction to Gases Earth is surrounded by a layer of gaseous molecules - the atmosphere - extending out to about 50 km.

6. Characteristics of Gases Gases  low density; compressible  volume = shape of container  expand when heated  large distance between particles Model of a gas:  rapidly moving particles: vol. & shape of container  no attraction between particles  moving about freely  large space between particles: low density & high compressibility 12m05vd1

7. Liquids and Solids Liquids  higher density, lower compressibility  characteristic volume; shape of container  particles closer together; moving about; experience attractive forces Solids  high density; low compressibility  particles are close together; little empty space; strong attractive forces  characteristic volume and shape

8. Atomic View of the States of Matter Note distance between particles and order of arrangement of particles Figure 9.1 01m07an1

9. States of Matter

10. Pressure Pressure = force/area Units: lb/ft 2 Pa = N/m 2 = kg/ms 2 torr = mm Hg atm 1 atm = 760 torr= 760 mm Hg 1 atm = 29.9 in Hg = 14.7 lb/in 2 1 atm = 101.3 kPa Measure pressure with barometer or U- tube or manometer

11. Charles’ Law- Relationship between: _________ and __________ Variables/Units Held Constant Relationship (direct or inverse) In words T = K V = L P = atm n = moles Direct As temperature increases, volume increases

12. Charles’ Law Graph of Relationship

13. Charles’ Law Charles’ Law Formula How to convert C to K F to C to K V/T = m m= constant V 1 /T 1 = V 2 /T 2 K = C + 273 C = 5/9(F-32) K = C + 273

14. Charles’ Law Temperature Conversion Practice Practice Problem Convert 212 degrees F to K Convert 50 degrees C to K The volume of a sample of gas is 2.50L at 45K. What is the volume when it is heated to 125K at a constant pressure.

15. Pressure Why does a pin hurt? Why don’t snowshoes sink?

16. Boyle’s Law: The relationship between _______ & ________ Variables/Units Held Constant Volume (L) Pressure (atm) Temperature (K) Moles (n)

17. Boyle’s Law: Relationship (direct or inverse) Relationship in words Inverse As pressure increases volume decreases.

18. Boyle’s Law Sketch Graph Pressure vs. Volume

19. Boyle’s Law Sketch Graph Pressure vs. 1/ V

20. Boyle’s Law Formula Pressure Units PV = m m = constant P 1 V 1 = P 2 V 2 atm = atmospheres mmHg = millimeters of mercury torr Pa = Pascals psi = pounds per square inch 1 atm = 101,325Pa = 760 mmHg = 760 torr = 14.70psi

21. Boyle’s Law Formula Pressure Unit Conversions 1 atm = 101,325Pa = 760 mmHg = 760 torr = 14.70psi

22. Boyle’s Law How to convert from pressure units to atm (use dimensional analysis) Convert 458mmHg to atm Convert 96.5 psi to atm Convert 485kPa to atm

23. Boyle’s Law Boyle’s Law Practice Problem The pressure on 2.5L of anesthetic gas is changed from 760mmHg to 304mmHg. What will be the new volume of the gas?

24. STP: Standard Temperature and Pressure 0 o C (273 K), 1 atm

25. HONORS CHEMISTRY (5/6)

26. Open Note Quiz (5/6) Place Homework on your desk  Textbook Notes  Charles and Boyles’ Laws Worksheet Time – 10 minutes

27. Unit Conversion for Gas Laws Calculations Convert to the following units P = atm V = Liters T = Kelvin ( o C + 273)

28. Agenda Open Note Quiz Grade Homework  Charles & Boyles’ Laws Worksheet Exploring Gas Behavior

29. Exploring Gas Behavior Activity Refer to Handout

30. HONORS CHEMISTRY May 11, 2012

31. Brain Teaser The pressure on 5.5 L gas is changed from 3 atm to 5 atm. What will be the new volume of the gas? The volume of a sample of gas is 4 mL at 40 o C. What is the volume when it is heated to 60 o C at a constant pressure?

32. Agenda Brain Teaser Grade Worksheet: Charles and Boyles’ Law Worksheet Notes: Combined Gas law, Avogadro’s Law and Ideal Gas Law Homework  Ideal Gas Law and Combined Gas Law Worksheet

33. Combined Gas Law Boyle’s Law Charles’s Combined

34. Avogadro’s Law How can we change the volume of a gas in a balloon?

35. Avogadro’s Law Why did the blimp deflate?

36. Avogadro’s Law If the pressure and temperature are held constant, the volume of a gas is directly proportional to the number of moles (n). V n

37. Gas Laws Part 2: Work on Gas Notes Sheet instead of Brain Teaser Avogadro’s Law O 2  O 3 Suppose we have a 12.2 L sample containing 0.50 mol oxygen gas at a pressure of 1 atm and a temperature of 25 º C. 1) Balance the equation 2) If all this oxygen is converted to ozone at the same temperature and pressure, what would be the volume of the ozone?

38. The total pressure is the sum of the partial pressures. Ptotal = P1 + P2 + P3 + …..

39. Dalton’s Law Practice A mixture of oxygen, carbon dioxide, and nitrogen has a total pressure of 0.97atm. What is the partial pressure of Oxygen, if the partial pressure of carbon dioxide is 0.70atm and the partial pressure of nitrogen is 0.12atm?

40. The Gas Laws Variables: V, P, T, n (or m and MM or d) Ideal Gas: properties are independent of the identity of the gas What is the relationship between the variables for an ideal gas? BasketballBike Tire

41. 5.3 Ideal Gas Law PV = nRT P= pressure V = volume n = number of moles R = ideal gas constant  0.08206 L·atm/mol·K T = temperature

42. STP Standard Temperature and Pressure  0 º C and 1 atm Use the Ideal Gas Law to calculate the volume of 1.00 mol of gas at STP

43. Molar Volume at STP We can show that 22.414 L of any gas at 0  C and 1 atm contain 6.02  10 23 gas molecules.

44. Example A sample of Hydrogen gas has a volume of 8.56 L at 0 ºC and a pressure of 1.5 atm. Calculate the moles H 2 molecules present in this gas sample.

45. Practice Problem The volume of an oxygen cylinder is 1.85 L. What mass of oxygen gas remains in the cylinder when it is “empty” if the pressure is 755 torr and the temperature is 18.1 o C? Answer: 2.46 g

47. Gas Law Stoichiometry Quicklime (CaO) is produced by the thermal decomposition of calcium carbonate. Calculate the volume of CO 2 at STP produced from the decomposition of 152 g of CaCO 3 by the reaction CaCO 3 (s)  CaO (s) + CO 2 (g)

48. Molar Mass and the Ideal Gas Law If 0.126 g of a gas are contained in a 25mL tank at 25 ºC and 3.25 atm, what is the molar mass of the gas? What is the gas?

49. Kinetic Molecular Theory A model that attempts to explain the behavior of an ideal gas. The particles are so small that compared with the distances between them that the volume of the individual particles can be assumed to be negligible (zero). The particles are in constant motion. The collisions of the particles with the walls of the container are the cause of the pressure exerted by the gas.

50. Kinetic Molecular Theory The particles are assumed to exert no forces on each other; they are assumed to neither attract nor repel each other. The average kinetic energy of a collection of gas particles is assumed to be directly proportional to the Kelvin temperature of the gas.

51. When does the Kinetic Molecular Theory break down? What conditions would cause our assumptions to become in valid?

52. Derivations from the Ideal gas law: Derivations occur in non-ideal conditions such as low temperature or high pressure: At high density the volume of the particles themselves become important. Gas particles do attract each other when they are close together.

53. Barometer What is in a vacuum? What is the weight of the atmosphere? Figure 9.3

54. Pressure Lab: soft drink can

55. Charles’ Law As x increases, y stays the same, no relationship. y = b y is constant As x increases, y increases Y = mx + b As x increases, y decreases Y = m(1/x) + b

56. Team A sample of nitrogen occupies a volume of 250 mL at 25 ºC. What volume will it occupy at 95ºC. Fluorine gas at 300 K occupies a volume of 500 mL. To what temperature should it be lowered to bring the volume to 300 mL?

57. Boyle’s Law by the Book Lab investigation

58. Pop Quiz: Boyle’s Law Sulfur dioxide, a gas that plays a central role in the formation of acid rain, is found in the exhaust of automobiles and power plants. Consider a 1.53 L sample of gaseous sulfur dioxide at a pressure of 5.6 x 10 3 Pa. If the pressure changed to 0.148 atm at a constant temperature, what will be the new volume of gas?

59. GROUP WORK Charles and Boyle’s Law Worksheet