AP* Chemistry
PROPERTIES OF SOLUTIONS
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© 2008 by René McCormick. All rights reserved.
IMPORTANT TERMS
¾ Solution—a homogeneous mixture of two or more substances in a single phase.
Does not have to involve liquids. Air is a solution of nitrogen, oxygen, carbon dioxide etc.;
solder is a solution of lead, tin etc.
solute—component in lesser concentration;
dissolvee
solvent
—component in greater
concentration; dissolver
¾ solubility
—maximum amount of material that
will dissolve in a given amount of solvent at a
given temperature to produce a stable solution.
In other words, the solution is saturated.
Study the solubility rules!!
¾ molar solubility—the number of moles of solute that dissolves in exactly 1.0 L of solvent,
expressed in units of molarity, M or the use of square brackets.
¾ Saturated solution— a solution containing the maximum
amount of solute that will dissolve under a given set of
pressure and temperature conditions. Saturated solutions are
at dynamic equilibrium with any excess undissolved solute
present. Solute particles dissolve and recrystallize at equal
rates.
¾ Unsaturated solution— a solution containing less than the
maximum amount of solute that will dissolve under a given
set of conditions. (more solute can dissolve)
¾ Supersaturated solution
—oxymoron—a solution that has
been prepared at an elevated temperature and then slowly
cooled. It contains more than the usual maximum amount of
solution dissolved. A supersaturated solution is very
unstable and agitation (stirring, pouring, etc.) or the
addition of a “seed crystal’ will cause all excess solute
to crystallize out of solution leaving the remaining
solvent saturated. (rock candy is made this way as are
those liquid hand warmer packets of sodium acetate
solution, pictured at left, folks use hunting, at football
games, skiing, etc.)