Unit: Aqueous Solutions
Lesson: #1
Aqueous Solutions
A solution is a mixture made up of a solvent and at least one solute.
Solutes and solvents may be gases, liquids or solids.
An aqueous solution is any solution where water is the solvent.
All aqueous solutions are transparent and may be colored or colorless.
Electrolytes are soluble compounds which conduct electricity when dissolved. All soluble
ionic compounds are electrolytes, acids are also electrolytes.
When an ionic compound dissolves, the + and – ions separate from each other. Electricity is
conducted from one free ion to another.
Non-electrolytes are soluble compounds which do not conduct electricity when dissolved.
Molecular compounds are non-electrolytes.
Formation of Solutions
When a solid dissolves, the individual particles separate from each other and spread out in
solution.
Separation is the spreading out of individual molecules that takes place when a molecular
compound is dissolved in water.
A soluble molecular compound disperses electrically neutral molecules throughout the
solution.
EX. dissolving sugar
C
H
O
C
H
O
12
22
11 (s)
12
22
11 (aq)
NOTE: no ions are present in solution solution will not conduct electricity
The crystals of soluble ionic compounds break apart into individual ions that spread
throughout the solution. This process is known as dissociation.
Ex. dissolving sodium chloride