Book L, Chemical Interactions
Chapter 3, Acids, Bases, and Solutions
Section 1, Working with solutions
Solution
- an evenly mixed mixture
- cannot be separated by filtration
examples:
salt in water
brass -- a solution of zinc and copper
Suspension
- an unevenly mixed mixture
- can be separated by filtration
examples:
sand and water
whole milk
Parts of a solution
solvent -- larger amount
solute -- smaller amount
- is dissolved in the solvent
example:
Sea water is about 3%salt and 97% water.
The water is the solvent and the salt is the solute.
Concentration
- a way to describe the amount of solute in a solvent
- dilute solution -- just a little solute in the solvent
example:
Kool-Aid powder in a pitcher of water
-concentrated solution -- a lot of solute in the solvent
example:
lots of sugar in tea
Solubility
- a measure of how much solute can dissolve in a solvent at a given temperature
- can be used to identify a compound.
(see p. 84, Figure 6)
Saturated solution
- a solution in which no more solute can be dissolved in the solvent at that temperature
Unsaturated solution
- more solute can be dissolved in the solvent at that temperature
Variables that affect solubility:
1. temperature
- usually higher temperatures will increase solubility
2. solvent
- similar compounds will dissolve in each other
Effects of solutes on solutions:
Solutes lower the freezing point of a solvent
examples:
salt on ice or snow
making ice cream
Solutes raise the boiling point of a solvent
examples:
salt in water to cook pasta
Solubility curves
