2. Solutions and Colloids

3. Solutions definition

4. Solutions

5. 9 (actually 7 or 5) types of solutions

6. Solution is a dynamic equilibrium process as a balance of dissolving and precipitating

7. Why do substances dissolve? (potential solutes)

9. Thermodynamic parts of the dissolving process

10. Energy diagram for dissolving

11. Change in solubility with Temperature for gaseous solutes for solid (ionic) solutes Heat to “de-gas” solutions A beaker of cold tap water develops air bubbles as it warms to room temperature. Most ionic solutes increase in solubility as temperature increases

12. Effects of pressure of solubility of gases

13. A sample problem & applications of Henry’s Law

14. Some reasons to learn about solubilities (Uses and Applications of Solubility)

15. Miscible and Immiscible Water and alcohol are miscible. Oil-and-water is an immiscible system.

16. Classification of solvents

17. As the organic alcohol part of the molecule is shortened, the solubility in water increases and the solubility of NaCl in the alcohol increases (see below).

18. Ionic solids dissolve in water because they become hydrated by water

19. Hydration of ions provides the energy of hydration which is the main exothermic part of the energy of dissolving

20. Colloidal Dispersions Suspension or under microscope beyond microscope

21. Eight types of Colloids (out of a possible 9) with names

22. Properties of Colloids

23. Tyndall effect Projector’s Light off Projector’s White light on Light beam is invisible in a true solution, but the beam is seen when it passes through any colloidal dispersion because the light is scattered by the colloidal-sized “micro-droplets” (Rayleigh scattering). Whenever you can see a beam of light (like the headlight beam of a car) it is due to the Tyndall effect through fog, mist, smoke or other colloid . Laser beam visible in a colloidal dispersion.

27. Colloidal silver: an alleged antibiotic

30. Salt-in-water solutions of different concentrations Dilute 0.01 molar = 0.01 M = 0.01 moles/Liter Not so dilute 0.1 molar = 0.1 M Concentrated 0.6 molar = 0.6 M (seawater) = 3.5 % = 3.5 grams/Liter

32. Unsaturated, Saturated, and Supersaturated

33. Pictures taken seconds apart after a seed crystal of Na 2 SO 4 is dropped into a supersaturated solution of Na 2 SO 4

34. Supercooled glacial acetic acid

35. Four aspects of concentration units

37. Higher concentration does not always give a stronger effect

38. Part-per-Whole Ratio

39. Percentage calculations

40. Mole fraction

42. Definitions of the main concentration units used in chemistry

43. What to write, say, and think

45. Advantages and Disadvantages of each of the main concentration units

46. Some reasons to learn about concentration units (and their calculations)

47. Steps to prepare a solution

48. Preparation of a solution of known concentration

49. Problem on How to Prepare a Solution

50. Labeling a solution

51. Bottle labels usually do not list the full ionic composition

52. How to convert concentration units

53. Converting concentration units (continued)

54. Converting concentration units

55. Calculations for dilution of solutions

56. Before dilution After dilution

57. Calculations for mixing of solutions

58. Ten-fold serial dilution of potassium permanganate

60. Solution Stoichiometry

61. Titration stoichiometry Here A is for acid, and B is for base.

62. Limiting Reactant using solutions

63. More solution stoichiometry Q: If 37 mL of 0.52 M dichromate react with excess methanol, CH 3 OH, how many moles of formaldehyde will be formed if the dichromate is completely used up?

64. Highest & Lowest Possible Concentrations

65. Solution terminology

66. Solutions outline