1. Solubility

2. Solubility
Ability of one substance to dissolve in another at a given temp and pressure
Usually measured as mass (g) of solute in 100g H2O at a given temp

3. Saturated- max amount of solute at a given temp
If more solute is added, it will not dissolve
Unsaturated- less than max amount of solute at a given temp
If more solute is added it will dissolve up to the point of saturation
Supersaturated – more than max amount of solute at a given temp
Saturated solution made at a higher temp then cooled. The solute remains dissolved in the solution.
Example: Sweet Tea

4. Supersaturated Solutions
Saturated solution made at a higher temp then cooled. The solute remains dissolved in the solution.
Often if disturbed or if additional crystals (seed crystals) are added recrystallization of solute will occur
The amount of solute that recrystallizes is the amount above the saturation point for the new temp
Example: rock candy
When cooled recrystallization occurs as the solution cools
Not all solutions can become supersaturated

5. Solubility Curves
Lines show saturation for that substance in 100g H2O at various temps
Points above line supersaturated
Points below line unsaturated

6. Go to temperature, trace up to the solubility curve of the compound you are interested in, trace across to the g/100g water.
If you are reducing temperature, subtract higher temperature amount from lower temperature amount. That will tell you how much will precipitate out.

7. If a saturated solution of KNO3 at 80 ⁰C was cooled to 20 ⁰C, what mass of crystals would form?
170g – 30g = 140g
How many g NaCl would be dissolved 100g of a saturated solution of water at 60 ⁰C?
40g
What is the solubility of NaClO3 at 40⁰C? 130g If a solution at 60 ⁰C contains 110g KBr is it US, S, or SS? S

8. For the homework ammonia- NH3 sodium nitrate – NaNO3
potassium chloride- KCl
potassium chlorate- KClO3
potassium nitrate – KNO3