1. SOLUTIONS & SOLUBILITIES

2. Goals for this lessons Identify te solute and te solvent in a solution
Define the terms «saturated», «unsaturated», «diluite» and «concentrated»
Use a solubility charte to determine maximum rations of solute to solvent
Identify factors influencing solubility

3. Revision What is a MIXTURE?
Two or more materials that can be physically separated

4. Definition
a mixture is a material system made up of two or more different substances which are mixed but are not combined chemically.
A mixture refers to the physical combination of two or more substances.

5. MIXTURE Heterogeneous Homogeneous
the composition is uniform and every part of the solution has the same properties
the components can be seen, as there are two or more phases present

6. Solutions
Solution – a homogeneous mixture of two or more pure substances
Major component = solvent, dissolves the solute
Minor component = solute, is being dissolved
Example:
Solution: Salt Water
Solute: Salt
Solvent: Water

8. KINDS OF SOLUTIONS

9. solutions
CONCENTRATED
DILUTE

10. SOLUBILITY
The maximum amount of solute that will dissolve in a solvent under certain conditions

11. A solution is saturated when no additional solute can be dissolved at a particular temperature
An Unsaturated solution is formed when more of the solute can dissolve in it at a particular temperature.

12. A Supersaturated solution can form when more than the equilibrium amount of solute is dissolved at an elevated temperature, and then the supersaturated solution is slowly cooled.

13. HOW DO SUBSTANCES DISSOLVE?
“According to the kinetic theory, the water molecules in each glass of tea are always moving. Some moving water molecules collide with sugar crystals. When this happens, energy is transferred to the sugar molecules at the surface of the crystal.” (Holt, p. 192)

14. Like dissolves like
Polar solvents (water) dissolve polar/ionic solutes
Nonpolar solvents (oil) dissolve nonpolar solutes

15. Factors affecting rate of dissolution:
The nature of the solute and solvent:
different substances have different solubilities
Surface area / particle size
Greater surface area, faster it dissolves
Agitation
Stirring/shaking will speed up dissolution
Temperature
Most solids dissolve faster at higher temps
Pressure:
Only affects the solubility of gases. As pressure increases, the solubility of gases increases

17. SOLUBILITY GRAPH OF GASES IN WATER

18. Gas solubility & pressure