1. Solubility
Chapter 15.1 B

2. Vocabulary Word
Solubility: the maximum amount of solute that dissolves in a given amount of solvent at a specific temperature and pressure

3. Solubility
Every solute has a characteristic solubility

4. Solvation
Particles of solvent collide with particles of solute  dissolving
As more and more solute dissolves, some of the dissolved solute particles collide with the remaining crystalline solute  crystallization

5. Solvation
As long as dissolving rate > crystallization rate more solute will continue to dissolve (unsaturated solution)
Eventually dissolving rate = crystallization rate (dynamic equilibrium: saturated solution)

6. Factors Affecting Solubility
Solubility is how much solute will dissolve (NOT how fast it dissolves)
Temperature
Pressure

7. Temperature Effects
Many substances are more soluble at higher temperature
More sugar or salt will dissolve in hot liquid than in cold liquid

8. Temperature Effects Gases are less soluble at higher temperatures
As the temperature increases the kinetic energy increases. This allows gas particles to escape to the atmosphere

9. Temperature Effects

10. Supersaturated Solutions
Since solubility of some solids increases with temperature:
Allows the formation of supersaturated solutions
Make a saturated solution at an elevated temperature
Cool slowly

11. Vocabulary Word
Supersaturated solution: a solution that contains more dissolved solute than a saturated solution at the same temperature.

12. Supersaturated Solutions
Are unstable
Add a seed of solute  crystallization

13. Supersaturated Solutions
Are unstable
Will crystallize on scratches of the container
Will crystallize if tapped or stirred

14. Examples of Supersaturated solutions
Cloud seeding: silver iodine is spread in the atmosphere to cause water particles in supersaturated air to condense and rain to fall

15. Examples of Supersaturated solutions
Mineral springs have salt crystals along the edge

16. Examples of Supersaturated solutions
Rock candy is made using a supersaturated solution of sugar water

17. Pressure Effects on Solubility
Solubility of gaseous solutes increase with increasing pressure (the soft drink won’t go flat as quickly if the lid is kept on)

18. Pressure Effects on Solubility
Soft drinks are carbonated at high pressure
When the cap is unscrewed, gas escapes

19. Spangler Video Clip supersaturated solutions:

20. Vocabulary Word
Henry’s law: the solubility of a gas in a liquid is proportional to the pressure of the gas above the liquid
S1 = S2 solubility at pressure 1
P1 P2 solubility at pressure 2

21. Henry’s Law
Is used to determine the solubility at different pressures