
Notes: Solutions and Solubility
o The formation of solutions is a physical change forming a homogeneous mixture.
o A solution is made up of a solute and a solvent.
 The solvent does the dissolving.
 The solute is the substance that is dissolved.
o Some things dissolve easier in one kind of substance as opposed to another.
 Sugar dissolves easily in water and oil does not.
 Water has a low solubility when it comes to oil. Since oil is not soluble in water, it will never
truly dissolve.
o A solute will dissolve in a solvent if the solute-solvent forces of attraction are great enough to
overcome the solute-solute and solvent-solvent forces of attraction.
o A solute will not dissolve if the solute-solvent forces of attraction are weaker than individual solute
and solvent intermolecular attractions.
o “Like dissolve like”
o The expression means that dissolving occurs when similarities exist between the solvent and the
solute.
 Water is polar, while C6H14 and CCl4 are nonpolar.
 As a result, neither substance will dissolve in water.
o Solubility- the maximum quantity of the substance, expressed in grams that will dissolve in a certain
solvent at a specific temperature.
o Types of solution
 Saturated – a solution that contains the maximum quantity of solute that dissolves at that
temperature.
 Unsaturated – a solution that contains less than the maximum amount of solute that can
dissolve at a particular temperature.
 Supersaturated – a solution that contains more solute than a saturated solution.
 Supersaturated solutions can be attained by heating the solution up to dissolve
more solute at that higher temperature and then letting the solution cool.
 Once cooled, agitation causes crystals to precipitate (separate from solution) out of
the supersaturated solution.
o Solubility and Temperature
 Increasing the temperature of solvent speeds up the particle movement. This causes more
solvent particles to bump into the solute, resulting in solute particles breaking loose and
dissolving faster.
o Solubility Curve
 A graph of the solubility of a compound (grams/100 grams water on the Y-axis) at various
temperatures (Celsius on X-axis). Each compound has a different curve.
o Solubility Curve Graph
 Solubility is dependent on temperature
 What trends do you see on the graph?
 How is the solubility of gases and solids different?
 If you stir faster, will that make you dissolve more?
 No, it allows you to dissolve substances faster but not more. Increasing the
temperature does allow you to dissolve more.
o Solids dissolve in liquid: solids are more soluble at…higher temperatures.
o Gases dissolved in liquids: Gases are more soluble at…lower temperatures and higher pressures.