1. the maximum amount of a substance that can be dissolved
Solubility
the maximum amount of a substance that can be dissolved

2. Solubility Solubility is a physical property.
Dissolving is a physical change.

3. Solvent The solvent does the dissolving:
Water dissolves many substances so we call it the universal solvent.
When alcohol is used as the solvent, the resulting solution is called a tincture.

4. Solute The solute is what dissolves Solvent + Solute = Solution
Example: If you want to make iced tea, you need the sugar and water.
Sugar = SOLUTE
Water = SOLVENT
Solvent + Solute = Solution

5. Making a solution
The solute enters the solvent and slowly breaks into pieces.
The molecules of the solvent move out of the way to make room for the solute.
The solute and solvent mix until the concentration is equal throughout the solution.

6. Solvent + Solute = Solution
Types of Solutions:
Solid Solvent + Solid Solute (gold jewelry)
Solid Solvent + Liquid Solute (dental filling)
Solid Solvent + Gas Solute (gas mask filter)

7. Solvent + Solute = Solution
Liquid Solvent + Solid Solute (salt water)
Liquid Solvent + Liquid Solute (rubbing alcohol)
Liquid Solvent + Gas Solute (soda)

8. Solvent + Solute = Solution
Gas Solvent + Solid Solute (smoke, air freshener)
Gas Solvent + Liquid Solute (fog, humidity)
Gas Solvent + Gas Solute (air)

9. Checkpoint Which of the following would be considered a solution?
A. 14k gold
B. Salt water
C. Carbonated water
D. All of the above

10. Checkpoint Which of the following would be considered a solution?
A. 14k gold
B. Salt water
C. Carbonated water
D. All of the above
Answer: D. all of the above

11. Factors Affecting Solubility
The nature of the solute and solvent
200 grams of zinc chloride can dissolve in 100 grams of water
but only
1 gram of lead chloride can dissolve in 100 grams of water

12. Examine the graph

13. Which is salt? Which is sugar?

14. Sugar Salt

15. Factors Affecting Solubility
2. Temperature
An increase in temperature increases the solubility of a solid solute.

16. Factors Affecting Solubility
2. Temperature
For all gases, solubility decreases as the temperature rises. Why?

17. Factors Affecting Solubility
2. Temperature
More heat = more kinetic energy (bouncing off each other)

18. Its easier to dissolve sugar in hot tea!

19. Factors Affecting Solubility
3. Pressure
Changes in pressure have no effect on the solubility of solids and liquids.
For gases, an increase in pressure increases solubility and a decrease in pressure decreases solubility.

21. Does pressure alter the solubility of solids or liquids? No!

22. Solubility of Gases
When the cap on a bottle of soda pop is removed, pressure is released, and the gas solute bubbles out. This escape of a gas from solution is called effervescence.

23. Checkpoint
Why does soda go flat if you leave it out without a cap?

24. Checkpoint Why does soda go flat if you leave it out without a cap?
Leaving the soda out without a cap means that there is less pressure in the system. Less pressure makes gases LESS soluble in a liquid.

25. How fast dissolving occurs depends on:
1. The size of the particles:
Dissolving only takes place at the surface of each particle.
When the total surface area is increased, the solute dissolves more rapidly.
Breaking a solute into smaller pieces increases its surface area and its rate of solution.

26. How fast dissolving occurs depends on:
2. Stirring brings fresh portions of the solvent in contact with the solute, thereby increasing the rate of solubility. For gases, stirring increases solubility ONLY if there is no pressure.

27. How fast dissolving occurs depends on:
3. The amount of solute already dissolved
When there is little solute already in solution, dissolving takes place rapidly.
As the solution approaches the point where no more can be dissolved, dissolving takes place more slowly.

28. How fast dissolving occurs depends on:
4. Temperature
For liquids and solid, increasing the temperature increases the rate at which the solute will dissolve.
For gases, the reverse is true. An increase in temperature decreases how fast dissolving occurs.

29. Interpreting graphs

30. At 80C, if we have 350 g of sugar in 100 ml of water is this saturated, supersaturated or unsaturated?

31. At 80C, if we have 350g of sugar in 100 ml of water is this….saturated. We can’t dissolve more sugar in the water.

32. There is undissolved solute in a
Saturated Solution

33. At 80C, if we have 100 g of sugar in 100 ml of water is this saturated, supersaturated or unsaturated?

34. At 80C, if we have 100 g of sugar in 100 ml of water is this…
At 80C, if we have 100 g of sugar in 100 ml of water is this….unsaturated. We can dissolve more sugar in the water.

35. At 80C, if we have 500 g of sugar in 100 ml of water is this saturated, supersaturated or unsaturated?

36. At 80C, if we have 500 g of sugar in 100 ml of water is this….
supersaturated.
We can’t dissolve more sugar in the water.

37. Unsaturated and supersaturated solutions look the same

38. But IF we try to add 1 more crystal of solute to a supersaturated solution

39. We get rapid crystallization. All the other solute starts to fall out!

40. Insoluble cannot dissolve in that solvent so…we don’t get solutions we get suspensions