1. Unit 6—Interactions of Matter Chapter 22---Solutions
Physical Science
Unit 6—Interactions of Matter
Chapter 22---Solutions
Note: You will not be able to view the videos from the internet version of this presentation. Copyright laws prevent that option.
Introductory Video 1 1

2. 22-1 How Solutions Form
Solution—a mixture that appears the same throughout and is mixed at the molecular level.
Solute --substance being dissolved.
Solvent –substance doing the dissolving. 2

3. 3. Solutions can be liquids, gases, or solids.
4. Alloys are solid solutions.
Video—Alloys :31 3

4. How dissolving happens:
22-1 How Solutions Form
How dissolving happens:
1. Water molecules are polar—they have a positive area and a negative area.
Video—Polar Molecules :45 4

5. Water molecules pull the solid particles into solution.
Water molecules cluster around solid molecules, with their negative ends attracted to the positive ends of the solids.
Water molecules pull the solid particles into solution. 5

6. 22-1 How Solutions Form
The moving water molecules and solid molecules spread out and mix evenly to form a solution.
To mix solids to make an alloy solution, you must melt the solid. 6

7. Rate of dissolving depends on:
22-1 How Solutions Form
Rate of dissolving depends on:
1. Stirring—speeds up dissolving by bringing more fresh solvent into contact with more solute. 7

8. a. Dissolving occurs at the surface of a solid
2. Crystal size
a. Dissolving occurs at the surface of a solid
b. Breaking a solid into pieces or powder increases its surface area, which speeds up dissolving. 8

9. 22-1 How Solutions Form
To make a gas dissolve more quickly in a liquid, cool the liquid solvent and increase the pressure of the gas.
Video Temp., pressure, Other Factors 1.59 9

10. 22-2 Dissolving Without Water
Non-polar materials have no positive or negative area.
They are not attracted to the polar water molecules, so they do not dissolve easily in water.
Video Non-Polar Molecules 1.49 10

11. Example: oils contain hydrocarbons.
Large molecules of carbon and hydrogen
These atoms share electrons in an equal manner, so there is not positive or negative charge. 11

12. 22-2 Dissolving Without Water
Useful non-polar molecules
Non-polar solvents dissolve non-polar solutes.
Many non-polar solvents are toxic—dangerous to touch or inhale.
Soap—used for washing because it has polar and non-polar properties. 12

13. 22-2 Dissolving Without Water
Polarity and Vitamins
B vitamins and vitamin C are polar—dissolve in the water in your body cells.
Vitamin A is non-polar –dissolves in the fat of some body cells. 13

14. 22-3 Solubility and Concentration
Solubility—the amount of a substance that can dissolve in a solvent
Depends on the nature of the substance
The solubility of two substances can be compared by measuring. 14

15. 22-3 Solubility and Concentration
1. A concentrated solution has a large amount of solute in the solvent 15

16. 22-3 Solubility and Concentration
2. A dilute solution has a small amount of solute in the solvent.
3. Concentrations can be expressed as percent by volume of the solute. 15

17. 22-3 Solubility and Concentration
Types of solutions.
Saturated solutions —contains all the solute it can hold at a given temperature. 17

18. 22-3 Solubility and Concentration
As the temperature of a liquid solvent increases, the amount of solid solute that can dissolve in it increases.
Solubility curve—line on a graph used to figure how much solute can dissolve at any temperature on the graph. 18

19. 22-3 Solubility and Concentration
Unsaturated solution —able to dissolve more solute at a given temperature.
Supersaturated solution —contains more solute than a saturated one at the same temperature 19

20. Super-saturated solution is made by raising temperature of a saturated solution, adding more solute, and lowering temperature back without disturbing the solution.
Video-Saturated-Supersaturated 1:22
Video-Temperature, etc. 1:59 20

21. b. Unstable– will crystallize if disturbed. c
b. Unstable– will crystallize if disturbed. c. As it crystallizes, it gives off energy and produces heat. 21

22. 22-4 Particles in Solution
Ions —particles with a charge
Electrolytes—compounds that form charged particles (ions) and conduct electricity in water.
Non-electrolytes—substances that do not ionize in water and cannot conduct electricity
Video—Ions 1.48 22

23. 22-4 Particles in Solution
How ions form
Ionization –molecules break apart in water, causing atoms to become ions by taking on a charge.
Dissociation —an ionic solid separates into its positive and negative ions. 23

24. 22-4 Particles in Solution
Effects of solute particles
All solute particles—polar, non-polar, electrolyte, and non-electrolyte—affect the physical properties of the solvent. 24

25. Adding a solute to a solvent lowers the freezing point because the added solute particles interfere with the formation of the orderly freezing pattern. 25

26. Adding a solute raises the boiling point because fewer solvent molecules can reach the surface and evaporate. 26

27. Review for the Test over Chapter 22
All Homework will be due _______.

28. Sometimes, but not always
REVIEW
Will increasing the temperature increase the solubility of a solute in a solvent?
Sometimes, but not always

29. Will the type of solution depend on the state of the solute?
REVIEW
Will the type of solution depend on the state of the solute? No

30. Are the particles of a a liquid moving?
REVIEW
Are the particles of a a liquid moving?
Yes, constantly.

31. REVIEW
When water dissolves sugar, are the positive ends of the water molecules attracted to the negative ends of the sugar molecules?
No.

32. Which particles move more freely: solid, liquid or gas?
REVIEW
Which particles move more freely: solid, liquid or gas?
Gas. Solids move less freely.

33. REVIEW
True or false: The dissolving process for solid solutions occurs in the solid state.
False

34. Will salad oil dissolve in vinegar?
REVIEW
Will salad oil dissolve in vinegar? No

35. REVIEW
Oil-based paints, nail polish and iodine are examples of _______ solutions.
Non-polar

36. Water can be used to dissolve _______ molecules.
REVIEW
Water can be used to dissolve _______ molecules.
polar

37. Explain why Vitamin C is polar.
REVIEW
Explain why Vitamin C is polar.
Vitamin C has several oxygen-to-hydrogen bonds resembling those found in water.

38. Does a non-polar material have separated positive and negative areas?
REVIEW
Does a non-polar material have separated positive and negative areas? No

39. REVIEW
Describe the sharing of electrons by hydrogen and carbons in hydrocarbons.
They share electrons nearly equally.

40. Explain how to express the concentration of a solution to solute.
REVIEW
Explain how to express the concentration of a solution to solute.
Express in terms of percentage by volume of the solute.

41. REVIEW
If a drink has 10% fruit juice does this mean that it is 100% by volume of the drink?
No, it is only 1/10 fruit juice.

42. REVIEW
What is a solute?
The substance being dissolved.

43. REVIEW
A _______ does not conduct an electric current when it forms a solution.
A non-electrolyte.

44. REVIEW
A soltion that contains all of the solute it can hold at a given temperature is ____.
Saturated

45. REVIEW
The process by which the positive and negative ions of a crystalline solid separate in water is called _______.
dissociation

46. Increasing the surface area of a solid will ____ the rate of solution.
REVIEW
Increasing the surface area of a solid will ____ the rate of solution.
speed

47. REVIEW
When a gas is dissolved in a liquid, the gas dissolves faster if the liquid is _____.
Cooled.

48. REVIEW
The concentration of a solution that contains a large amount of solute in the solvent could be described as ____.
concentrated

49. An alloy is an example of a ____ solution.
REVIEW
An alloy is an example of a ____ solution.
solid

50. Adding more solute to a solvent increases its ______.
REVIEW
Adding more solute to a solvent increases its ______.
Boiling point

51. REVIEW
A molecule that is positively charged on one end and negatively charged on the other end is ____.
Polar.

52. REVIEW
The amount of solute that can be dissolved in a specific amount of solvent at a given temperature is its ______.
solubility.

53. REVIEW
If we increase the pressure and decrease the temperature we would ____ the solubility of a gas in a liquid.
increase

54. REVIEW
Stirring the solution will ____ the speed of dissolving of the solid in water.
increase