1. Ch. 16
Solutions

2. “Like dissolves Like” How to identify the types
IONIC
POLAR COVALENT
NONPOLAR COVALENT
Metal/nonmetal
NM/NM eneg diff >.5
NM/NM eneg diff <.4
Polyatomic ions
COH, alcohol
(methanol, ethanol)
-ene, ane, yne endings - CH
Roman numerals
Sugars -ose
Diatomic molecules
Electrolytes
C2H5OH (ethanol)
Br2
KCl, FePO3
C6H12O6 (sugar)
Toluene, benzene C6H6
Oil, gasoline

3. Solution Formation
3 Factors that affect speed of solution formation for solid solute:
Agitation (stirring): delivers fresh solvent to solute
Temperature increase: increases kinetic energy
Surface area (crushing): increases surface area so more solvent has access to solute

4. Solubility
Solubility: How much solute can be dissolved in a solution at a particular temperature.
Miscible: 2 soluble liquids (alcohol and water)
Immiscible: 2 Insoluble liquids (oil and water)

5. Factors Affecting Solubility
Temperature:
For solid/liquid solute: increase temperature increases solubility.
Hot tea dissolves more sugar than iced tea.
For gases: increase temperature DECREASES solubility
Hot gas moves too fast to be
“captured” by liquid well.

6. (Factors that affect solubility)
Pressure (only affects gases)
Increase pressure increases solubility.

7. Relative concentration:
Unsaturated: contains less solute than possible (at that temp)
Saturated: Contains maximum solute (at that temp.
Supersaturated: Contains more solute than it theoretically can hold (at that temp)

8. Unsaturated Solution Dissolves completely
add a seed crystal and it will dissolve.

9. Saturated Solution: may have a little solute at bottom
Add a seed crystal and it falls to bottom

10. Supersaturated Solution: may look just like saturated until you add a seed crystal then it crystallizes!

11. Solubility Graph and calculation
Solubility is determined in grams of solute
100 g of water
What is the solubility of sodium nitrate at 20oC?
How much ammonium chloride can be dissolved in 200g of water at 30oC?
How does gas solubility change with temp?