UNIT 4: SOLUTIONS AND SOLUBILITY
8.2 SOLUTIONS AND THEIR CHARACTERISTICS
A solution or homogeneous mixture is made up of two or more substances. It is called
homogeneous, because there is only one phase (ex. a mixture of water and salt). A heterogeneous
mixture is a mixture with two or more phases (ex. silver iodide and potassium nitrate – silver
iodide is the yellow solid and potassium nitrate is the solution).
Components of a Solution
 A solute is a substance or substances that are dissolved in a solvent; it is the substance present
in the smallest amount. A solute can be a solid, liquid or gas. A solvent is a substance with
other substances dissolved in it; it is often the substance present in the largest amount.
 Solutions can have variable composition or concentration, which is the ratio of solute to
solvent.
Concentrated Solution – Solution with a large quantity of solute compared to volume of solution
Diluted Solution – Solution with a small quantity of solute compared to volume of solution
Types and Examples of Solutions
- A solution can be a solid, liquid or gas.
- You can also have different combinations of solute and solvent states.
- Air is a gaseous solution made from nitrogen (78%), oxygen (21%), argon (0.9%) and carbon
dioxide (0.03%)
- A solution of two or more metals is called an alloy. Steel is an example of an alloy (of iron and
carbon) and bronze is also an alloy (of copper and tin).
- An aqueous solution is a solution in which water is the solvent. Most household substance and
chemicals in your labs are aqueous solutions.
Homework: Read Page 376-379 and Pg. 381 #1-9