1. Physical Science Mrs. Baker
Solutions
Physical Science
Mrs. Baker

2. Definitions Solution - homogeneous mixture
Solute - substance being dissolved
Solvent - present in greater amount

3. Definitions
Solute - KMnO4
Solvent - H2O

4. Types of Solutions Based on state of solvent.
All solid-liquid-gas combos are possible.
EX: dental amalgam (alloy of silver, mercury, etc.)
liquid solute, solid solvent
solid solution

5. Dissolving Solvation occurs at the surface of the solute
solvent particles surround solute particles (+/- attraction)
solute particles are pulled into solution

6. NaCl dissolving in water

7. Rate of Solution Solids dissolve faster... more stirring
small particle size (increased surface area)
high temperature

8. Rate of Solution
Gases dissolve faster…
high pressure
low temperature

9. “Like Dissolves Like” NONPOLAR POLAR Detergents
polar “head” with long nonpolar “tail”
can dissolve both types

10. Electrolytes Electrolyte Weak Electrolyte Non- Electrolyte+
salt - +
acetic acid - +
sugar
Electrolyte
Weak
Electrolyte
Non-
Electrolyte
solute exists as
ions only
solute exists as
ions and
molecules
solute exists as
molecules only

11. B. Electrolytes Dissociation
separation of +/- ions when an ionic compound dissolves in water

12. Electrolytes Ionization
breaking apart of polar covalent molecules into ions when dissolving in water

13. Colligative Properties
properties of solutions that depend only on solute concentration
Freezing Point Depression
solutes lower the f.p. of a solvent
Boiling Point Elevation
solutes raise the b.p. of a solvent

14. Colligative Properties
Freezing Point Depression
View Flash animation.

15. Colligative Properties
Boiling Point Elevation
Solute particles “get in the way.”

16. Colligative Properties
Effect increases as the solute concentration increases.
Uses:
antifreeze
making ice cream
salting icy roads

17. Concentration Concentrated solution large amount of solute
Dilute solution
small amount of solute

18. Concentration % by Volume usu. liquid in liquid
EX: 10% juice = 10mL juice + 90mL water
% by Mass
usu. solid in liquid
EX: 20% NaCl = 20g NaCl + 80g water

19. Concentration UNSATURATED SOLUTION more solute dissolves
no more solute dissolves
SUPERSATURATED SOLUTION
becomes unstable, crystals form
concentration

20. Concentration
Percent by mass is grams of solute per total grams of solution.
Molarity is number of moles (how we count chemical substances) per Liter of solution.

21. Solubility Solubility
maximum grams of solute that will dissolve in 100 g of solvent at a given temperature
varies with temperature
based on a saturated solution

22. Solubility Solubility Curve
shows the dependence of solubility on temperature

23. Solubility Solids are more soluble at... high temperatures.
Gases are more soluble at...
low temperatures.
high pressures (Henry’s Law).