1. Slide 1 of 39 Chemistry 16.1

2. © Copyright Pearson Prentice Hall Properties of Solutions > Slide 2 of 39 Solution Formation What factors determine the rate at which a substance dissolves? 16.1

3. Slide 3 of 39 © Copyright Pearson Prentice Hall Properties of Solutions > Solution Formation The compositions of the solvent and the solute determine whether a substance will dissolve. The factors that determine how fast a substance dissolves are stirring (agitation) temperature the surface area of the dissolving particles 16.1

4. Slide 4 of 39 © Copyright Pearson Prentice Hall Properties of Solutions > Solution Formation A cube of sugar in cold tea dissolves slowly. 16.1

5. Slide 5 of 39 © Copyright Pearson Prentice Hall Properties of Solutions > Solution Formation Granulated sugar dissolves in cold water more quickly than a sugar cube, especially with stirring. 16.1

6. Slide 6 of 39 © Copyright Pearson Prentice Hall Properties of Solutions > Solution Formation Granulated sugar dissolves very quickly in hot tea. 16.1

7. Slide 7 of 39 © Copyright Pearson Prentice Hall Properties of Solutions > Solution Formation Stirring and Solution Formation Stirring speeds up the dissolving process because fresh solvent (the water in tea) is continually brought into contact with the surface of the solute (sugar). 16.1

8. Slide 8 of 39 © Copyright Pearson Prentice Hall Properties of Solutions > Solution Formation Temperature and Solution Formation At higher temperatures, the kinetic energy of water molecules is greater than at lower temperatures, so they move faster. As a result, the solvent molecules collide with the surface of the sugar crystals more frequently and with more force. 16.1

9. Slide 9 of 39 © Copyright Pearson Prentice Hall Properties of Solutions > Solution Formation Particle Size and Solution Formation A spoonful of granulated sugar dissolves more quickly than a sugar cube because the smaller particles in granulated sugar expose a much greater surface area to the colliding water molecules. 16.1

10. © Copyright Pearson Prentice Hall Properties of Solutions > Slide 10 of 39 Solubility How is solubility usually expressed? 16.1

11. Slide 11 of 39 © Copyright Pearson Prentice Hall Properties of Solutions > Solubility A saturated solution contains the maximum amount of solute for a given quantity of solvent at a given temperature and pressure. An unsaturated solution contains less solute than a saturated solution at a given temperature and pressure. 16.1

12. Slide 12 of 39 © Copyright Pearson Prentice Hall Properties of Solutions > Solubility In a saturated solution, the rate of dissolving equals the rate of crystallization, so the total amount of dissolved solute remains constant. 16.1

13. Slide 13 of 39 © Copyright Pearson Prentice Hall Properties of Solutions > Solubility The solubility of a substance is the amount of solute that dissolves in a given quantity of a solvent at a specified temperature and pressure to produce a saturated solution. Solubility is often expressed in grams of solute per 100 g of solvent. 16.1

14. Slide 14 of 39 © Copyright Pearson Prentice Hall Properties of Solutions > Solubility Some liquids combine in all proportions, while others don’t mix at all. Two liquids are miscible if they dissolve in each other in all proportions. Two liquids are immiscible if they are insoluble in each other. 16.1

15. Slide 15 of 39 © Copyright Pearson Prentice Hall Properties of Solutions > Solubility Oil and water are immiscible. 16.1

16. © Copyright Pearson Prentice Hall Properties of Solutions > Slide 16 of 39 Factors Affecting Solubility What conditions determine the amount of solute that will dissolve in a given solvent? 16.1

17. © Copyright Pearson Prentice Hall Properties of Solutions > Slide 17 of 39 Factors Affecting Solubility Temperature affects the solubility of solid, liquid, and gaseous solutes in a solvent; both temperature and pressure affect the solubility of gaseous solutes. 16.1

18. Slide 18 of 39 © Copyright Pearson Prentice Hall Properties of Solutions > Factors Affecting Solubility Temperature The solubility of most solid substances increases as the temperature of the solvent increases. The solubilities of most gases are greater in cold water than in hot. 16.1

19. Slide 19 of 39 © Copyright Pearson Prentice Hall Properties of Solutions > Factors Affecting Solubility 16.1

20. Slide 20 of 39 © Copyright Pearson Prentice Hall Properties of Solutions > Factors Affecting Solubility A supersaturated solution contains more solute than it can theoretically hold at a given temperature. The crystallization of a supersaturated solution can be initiated if a very small crystal, called a seed crystal, of the solute is added. 16.1

21. Slide 21 of 39 © Copyright Pearson Prentice Hall Properties of Solutions > Factors Affecting Solubility A supersaturated solution is clear before a seed crystal is added. 16.1

22. Slide 22 of 39 © Copyright Pearson Prentice Hall Properties of Solutions > Factors Affecting Solubility Crystals begin to form in the solution immediately after the addition of a seed crystal. 16.1

23. Slide 23 of 39 © Copyright Pearson Prentice Hall Properties of Solutions > Factors Affecting Solubility Excess solute crystallizes rapidly. 16.1

24. Slide 24 of 39 © Copyright Pearson Prentice Hall Properties of Solutions > Factors Affecting Solubility 16.1

25. Slide 25 of 39 © Copyright Pearson Prentice Hall Properties of Solutions > Factors Affecting Solubility Pressure Changes in pressure have little effect on the solubility of solids and liquids, but pressure strongly influences the solubility of gases. Gas solubility increases as the partial pressure of the gas above the solution increases. 16.1

26. © Copyright Pearson Prentice Hall Slide 26 of 39 16.1 Section Quiz. 1. For a given substance, which of the following will NOT influence how fast it dissolves? a.temperature b.amount of agitation c.molar mass d.size of the crystals

27. © Copyright Pearson Prentice Hall Slide 27 of 39 16.1 Section Quiz. 2. The solubility of a substance is often expressed as the number of grams of solute per a.100 liters of solvent. b.1 cm 3 of solvent. c.100 grams of solution. d.100 grams of solvent.

28. © Copyright Pearson Prentice Hall Slide 28 of 39 16.1 Section Quiz. 3. The solubility of a gas in a solvent is affected by a.both temperature and pressure. b.only pressure. c.only temperature. d.both pressure and agitation.

29. © Copyright Pearson Prentice Hall Slide 29 of 39 16.2 Molarity How do you calculate the molarity of a solution?

30. © Copyright Pearson Prentice Hall Slide 30 of 39 Molarity a.The concentration of a solution is a measure of the amount of solute that is dissolved in a given quantity of solvent. A dilute solution is one that contains a small amount of solute. A concentrated solution contains a large amount of solute. 16.2

31. © Copyright Pearson Prentice Hall Slide 31 of 39 Molarity a.Molarity (M) is the number of moles of solute dissolved in one liter of solution. b.To calculate the molarity of a solution, divide the moles of solute by the volume of the solution. 16.2

32. © Copyright Pearson Prentice Hall Slide 32 of 39 Molarity a.To make a 0.5-molar (0.5M) solution, first add 0.5 mol of solute to a 1-L volumetric flask half filled with distilled water. 16.2

33. © Copyright Pearson Prentice Hall Slide 33 of 39 Molarity a.Swirl the flask carefully to dissolve the solute. 16.2

34. © Copyright Pearson Prentice Hall Slide 34 of 39 Molarity a.Fill the flask with water exactly to the 1-L mark. 16.2

35. © Copyright Pearson Prentice Hall Slide 35 of 39 16.2

36. © Copyright Pearson Prentice Hall Slide 36 of 39 16.2

37. © Copyright Pearson Prentice Hall Slide 37 of 39 16.2

38. © Copyright Pearson Prentice Hall Slide 38 of 39 16.2

39. © Copyright Pearson Prentice Hall Slide 39 of 39 Problem Solving 16.8 Solve Problem 8 with the help of an interactive guided tutorial. for Sample Problem 16.2

40. © Copyright Pearson Prentice Hall Slide 40 of 39 16.3

41. © Copyright Pearson Prentice Hall Slide 41 of 39 Sample Problem 16.3 16.3

42. © Copyright Pearson Prentice Hall Slide 42 of 39 Sample Problem 16.3 16.3

43. © Copyright Pearson Prentice Hall Slide 43 of 39 Sample Problem 16.3 16.3

44. © Copyright Pearson Prentice Hall Slide 44 of 39 for Sample Problem 16.3

45. © Copyright Pearson Prentice Hall Slide 45 of 39 16.2 Making Dilutions What effect does dilution have on the total moles of solute in a solution?

46. © Copyright Pearson Prentice Hall Slide 46 of 39 Making Dilutions Diluting a solution reduces the number of moles of solute per unit volume, but the total number of moles of solute in solution does not change. 16.2

47. © Copyright Pearson Prentice Hall Slide 47 of 39 Making Dilutions a.The total number of moles of solute remains unchanged upon dilution, so you can write this equation. a.M 1 and V 1 are the molarity and volume of the initial solution, and M 2 and V 2 are the molarity and volume of the diluted solution. 16.2

48. © Copyright Pearson Prentice Hall Slide 48 of 39 Making Dilutions a.Making a Dilute Solution 16.2

49. © Copyright Pearson Prentice Hall Slide 49 of 39 Making Dilutions a.To prepare 100 ml of 0.40M MgSO 4 from a stock solution of 2.0M MgSO 4, a student first measures 20 mL of the stock solution with a 20-mL pipet. 16.2

50. © Copyright Pearson Prentice Hall Slide 50 of 39 Making Dilutions a.She then transfers the 20 mL to a 100-mL volumetric flask. 16.2

51. © Copyright Pearson Prentice Hall Slide 51 of 39 Making Dilutions a.Finally she carefully adds water to the mark to make 100 mL of solution. 16.2

52. © Copyright Pearson Prentice Hall Slide 52 of 39 Making Dilutions a.Volume-Measuring Devices 16.2

53. © Copyright Pearson Prentice Hall Slide 53 of 39 16.4

54. © Copyright Pearson Prentice Hall Slide 54 of 39 16.4

55. © Copyright Pearson Prentice Hall Slide 55 of 39 16.4

56. © Copyright Pearson Prentice Hall Slide 56 of 39 16.4

57. © Copyright Pearson Prentice Hall Slide 57 of 39 for Sample Problem 16.4 `

58. © Copyright Pearson Prentice Hall Slide 58 of 39 Percent Solutions What are two ways to express the percent concentration of a solution? 16.2

59. © Copyright Pearson Prentice Hall Slide 59 of 39 Percent Solutions The concentration of a solution in percent can be expressed in two ways: as the ratio of the volume of the solute to the volume of the solution or as the ratio of the mass of the solute to the mass of the solution. 16.2

60. © Copyright Pearson Prentice Hall Slide 60 of 39 Percent Solutions Concentration in Percent (Volume/Volume) 16.2

61. © Copyright Pearson Prentice Hall Slide 61 of 39 Percent Solutions a.Isopropyl alcohol (2-propanol) is sold as a 91% solution. This solution consist of 91 mL of isopropyl alcohol mixed with enough water to make 100 mL of solution. 16.2

62. © Copyright Pearson Prentice Hall Slide 62 of 39 16.5

63. © Copyright Pearson Prentice Hall Slide 63 of 39 16.5

64. © Copyright Pearson Prentice Hall Slide 64 of 39 16.5

65. © Copyright Pearson Prentice Hall Slide 65 of 39 16.5

66. © Copyright Pearson Prentice Hall Slide 66 of 39 Practice Problems For Sample Problem 16.5 Problem-Solving 16.15 Solve Problem 15 with the help of an interactive guided tutorial. for Sample Problem 16.5

67. © Copyright Pearson Prentice Hall Slide 67 of 39 Percent Solutions Concentration in Percent (Mass/Mass) 16.2

68. © Copyright Pearson Prentice Hall Slide 68 of 39 16.2 Section Quiz. 16.2.

69. © Copyright Pearson Prentice Hall Slide 69 of 39 16.2 Section Quiz. 1. To make a 1.00M aqueous solution of NaCl, 58.4 g of NaCl are dissolved in a.1.00 liter of water. b.enough water to make 1.00 liter of solution c.1.00 kg of water. d.100 mL of water.

70. © Copyright Pearson Prentice Hall Slide 70 of 39 16.2 Section Quiz. 2. What mass of sodium iodide (NaI) is contained in 250 mL of a 0.500M solution? a.150 g b.75.0 g c.18.7 g d.0.50 g

71. © Copyright Pearson Prentice Hall Slide 71 of 39 16.2 Section Quiz. 3. Diluting a solution does NOT change which of the following? a.concentration b.volume c.milliliters of solvent d.moles of solute

72. © Copyright Pearson Prentice Hall Slide 72 of 39 16.2 Section Quiz. 4. In a 2000 g solution of glucose that is labeled 5.0% (m/m), the mass of water is a.2000 g. b.100 g. c.1995 g. d.1900 g.