1. UNIT 6 SOLUTIONS AND GASES 6.2 What factors affect solubility?
April 8, 2010
AIM: What are the factors that affect solubility?
DO NOW:
List the factors that affect the rate of reaction.
What are the two parts of a solution?
Nature of the reactant Concentration
Surface area Pressure
Catalyst Temperature
SOLUTE and SOLVENT

2. SOLUTION CHECKLIST Homogeneous mixtures
Clear and do not disperse light
Can have color
Do not settle on standing
Pass through a filter

3. DEFINITIONS
Directions: Look up the definitions of the following words:
SOLUBILITY
SOLUBLE
INSOLUBLE

4. WORD DEFINITION SOLUBILITY How much of a solute will
Dissolve in a certain amount
Of solvent
SOLUBLE
Materials with high solubility
INSOLUBLE
Materials with low solubility

5. FACTORS THAT AFFECT SOLUBILITY
EFFECT
(READ: as temp increases, solubility of solids….)
EXCEPTIONS
TEMPERATURE
PRESSURE
POLARITY
Gases react in
Opposite way:
T gases
T solids
No effect on
Solubility of
Solids or liquids
Has an effect
On gases:
P gases
Polar dissolves polar
Nonpolar dissolves
nonpolar

6. A little more on polarity
TYPE
DEFINITION
POLAR
NONPOLAR
Symmetrical molecules
- Due to distribution of charge
Asymmetrical molecules
- Due to distribution of charge

8. TRY THE DEMONSTRATION

9. “LIKE DISSOLVES LIKE” Solute Type Nonpolar solvent Polar Solvent
Soluble
Polar
soluble
nonpolar
insoluble
insoluble
soluble
ionic
insolube

10. EXAMPLE
Greases, which are nonpolar, won’t easily wash off our hands in water, which is polar.
Soaps have one end that is polar, which allows the soap to dissolve in water. The other end of the soap is nonpolar, and grease will dissolve in it.

11. BRAIN STRETCHING
What kind of solvent will dissolve a polar solute? Give examples.
2. What kind of solvent will dissolve a nonpolar solute? Give examples.
3. Waterproof mascara won’t wash off with water, what might be a good substance to use to wash it off your face? Why?
POLAR SOLVENT
Ex. Water
NONPOLAR SOLVENT
Ex. GREASE, any molecule nonpolar
Oil or soap. Because the mascara is NONPOLAR and oil is NONPOLAR

12. 4. What happens to the solubility of solids and gases when the temperature of a solution is increased?
5. What happens to the solubility of solids and gases when the pressure on a solution is increased?
6. What does the phrase “like dissolves like” tell you about when something will dissolve and when it will not?
Temperature increase causes solubility of solids to increase and solubility of gases to decrease.
Pressure increase does not change solubility of solids but it increases the solubility of gases.
Polar will dissolve Polar
Nonpolar will dissolve Nonpolar

13. 7. In terms of distribution of charges, why is it that a polar substance will dissolve in a polar solvent, but not in a nonpolar solvent? You may need to review the definitions of polar and nonpolar to answer this question.
Because the attractive forces between two polar substances will be greater due to the uneven distribution of charge.
Attractive forces between a nonpolar and a plar substance are not strong enough.

14. INDEPENDENT PRACTICE Complete the Independent Practice
PLACE COMPLETED IP IN HOMEWORK BIN