1. 7.1 – NOTES Solubility of Solids

2. C.1 Solubility of Solids in Water
When you add a solute like salt or Kool-Aid powder to water, the solute will eventually dissolve with enough stirring. But then you keep adding more until the solute will not dissolve no matter how much you stir. What is happening?

3. Solubility Curve

4. Solubility-
The maximum amount of a substance that can dissolve in a certain amount of solvent (usually water) at a certain temperature.
Solids- solubility will increase if you increase temperature
Expressed as grams of solute per grams of solvent
(ie X g of KNO3 per 100 g H2O)

5. Solubility curves show - the relationship between the solvent, temperature, and the amount of solute dissolved at the temperature

6. Saturated solution Unsaturated solution
Holds maximum amount of solute at that temperature
Show on line on solubility curve
Unsaturated solution
Holds less solute than the max amount at that temperature – can add more solute
Under curve on solubility chart

8. Supersaturated solution
Holds more solute than you typically can at that temperature
These are made by heating the solvent and dissolving a large amount of solute then allowing the solution to cool
Located in area above the curve on solubility chart
Agitating one of these solutions just a little can cause the solute to come out of solution.
They are very fragile and can easily come out of solution. 
Examples include rock candy and mineral deposits around a hot spring.

10. Complete the Activity

11. Using the graph above, answer the following examples
At 50°C, how much KNO3 can dissolve in 100 g of water?
80g KNO3
What type of solution is created when 80 g of KNO3 is dissolved in 100 g of water at 60°C?
unsaturated
What would happen if you cooled the previous solution to 40°C?
Become supersaturated
At what temperature will the solubility of KNO3 be 25 g per 100 g of water?
18 degrees C
How much KNO3 will dissolve in 150 g of water at 40°C?
At 40 degree C, we can dissolve 60 grams KNO3 in 100 g of H2O
60 g KNO3 = x g KNO3
100 g H2O g H2O x = 90 g KNO3