Unit: Acids, Bases,
and Solutions
Introduction to Solutions
After today you will be able to…
• Explain the differences between
the three different types of
solutions
• Describe how to make a
supersaturated solution
• Describe how to increase the
rate of dissolving
A solution is a homogeneous
mixture. The components
are not chemically combined
and retain their original
properties.
Example: Sugar water – still
tastes sweet
Solutions
A solution is made up of a
solute and solvent.
•Solute: a dissolved substance
•Solvent: the most abundant
component of a solution,
what does the dissolving
Water is called the
“universal solvent”
because it has the
ability to dissolve so
many substances.
Solutions
Recall, aqueous is a
solution where water is
the solvent.
Example:
+
NaCl(aq) Na + Cl
Solubility 
The maximum amount of solute
dissolved in a particular solvent at a
specific temperature.
•Saturated: No more solute can
dissolve
•Unsaturated: More solute can dissolve
•Supersaturated: More solute is
dissolved than theoretically possible
To make a supersaturated
solution:
1. Add more solute than solubility
allows
2. Heat the solution up
3. Slowly cool it down
This is a temporary and unstable
state for a solution!
Factors that affect solubility:
1. Temperature: most solid substances
have higher solubility as temperature
increases
• All gas solutes have lower solubility as
temperature increases
2. Pressure: only affects gas solutes
• All gas solutes have higher solubility as
pressure increases
Solubility Curves
For Solid Solutes:
For Gas Solutes:
Rate of dissolving: How
fast a solute dissolves in
a solvent – not to be
confused with how much.
Rate can be increased by:
1. Increasing temperature- There is more
kinetic energy available to meet the
activation energy (energy available for
dissolving)
2. Stirring- Increases the interaction
between solute and solvent
3. Powdering- Increase surface area of the
solute which increases the interaction
between solute and solvent
Liquid-Liquid Solutions
• Miscible: two liquids which uniformly mix
together (ex: milk and water)
• Immiscible: two liquids which will not
mix, forms two layers (ex: oil and water)
As a general rule: “Like dissolves like”
Non-polar + non-polar = miscible
Polar + Polar = miscible
Non-polar + Polar = immiscible
Concentration
Indicates the amount of
solute dissolved in a
given quantity of
solvent.
• Dilute: a small
amount of solute
• Concentrated: a large
amount of solute
Questions?
Begin WS1