1. Properties of Solutions

2. Classification of Matter
Solutions are homogeneous mixtures

3. Solute Solvent A solute is the dissolved substance in a solution.
Salt in salt water
Sugar in soda drinks
Carbon dioxide in soda drinks
Solvent
A solvent is the dissolving medium in a solution.
Water in salt water
Water in soda

4. Solubility
If less than one gram of the substance will dissolve in 100 grams (or 100 mL) of solvent, the substance is considered insoluble.
If more than ten grams of substance will dissolve in 100 grams (or 100 mL) of solvent, the substance is considered soluble.
If between one and ten grams of a substance will dissolve in 100 grams (or 100 mL) of solvent, the substance is considered moderately soluble.

5. “Like Dissolves Like”
Nonpolar solutes dissolve best in nonpolar solvents
Fats
Benzene
Steroids
Hexane
Waxes
Toluene
Polar and ionic solutes dissolve best in polar solvents
Inorganic Salts
Water
Sugars
Small alcohols
Acetic acid

6. Solubility of Ionic Compounds in Water
The polar charges on water molecules are attracted to the opposite charge on the ions in ionic compounds
If this attraction causes the ions to separate (“dissociate”), then the ionic compound “dissolves”
Ionic compounds that are soluble, always form ions in solution

7. Soluble Ionic Compounds
K2CrO4(aq) + Ba(NO3)2(aq)

8. Solubility of NaCl in Water

9. Electrolytes and Nonelectrolytes
An electrolyte is:
A substance whose aqueous solution conducts an electric current
Ionic compounds form electrolytes when they dissolve, because the ions separate and move around independently
A nonelectrolyte is:
A substance whose aqueous solution does not conduct an electric current
Molecular compounds do not form electrolytes when they dissolve

10. Electrolytes vs. Nonelectrolytes

11. Solubility of Molecular Compounds in Water
•If we are comparing the water solubility of two similar molecules, the one with the higher percentage of the molecule that is polar (hydrophilic) is expected to have higher water solubility.
•We predict that the molecule with the higher percentage of its structure that is nonpolar (hydrophobic) to be less soluble in water.

12. Hydrophobic and Hydrophilic

13. Methamphetamine

14. Triglycerides (Fats and Oils)

15. Tristearin

16. Tristearin –Line Drawing

17. Making Soap

18. Soap and Detergent

19. Cleaning Greasy Dishes

20. Oil Droplets and Soap or Detergent

21. Solubility Trends
The solubility of MOST solids increases with temperature.
The rate at which solids dissolve increases with increasing surface area of the solid.
The solubility of gases decreases with increases in temperature.
The solubility of gases increases with the pressure above the solution.

22. Using Coffee…
Cold Warm Hot Water Water Water

23. Solubility and Temperature
Temperature affects how much solute dissolves (solubility)
Temperature affects how quickly a solute dissolves (rate)
Increasing the temperature not only increases the amount of solute that will dissolve but also increases the rate at which the solute will dissolve

24. Therefore… Solids tend to dissolve best when: Heated Stirred
Ground into small particles
Gases tend to dissolve best when:
The solution is cold
Pressure is high

25. Solubility Chart