|A solution is a homogeneous mixture of two or more substances, distinguished from non-homogeneous mixtures such as colloids and suspensions. There may be solid, liquid, or gaseous solutions. For certain types of liquid solutions, it is useful to describe the solution as comprised of one or more solutes dissolved within a solvent. The solubility of a solute describes its ability to dissolve in a certain solvent. A variety of concentration expressions are useful within different contexts to describe the composition of a solution including mole fraction, percent by weight, molarity, and molality. The colligative properties refer to the changes that occur in the physical properties of a solvent when a solute is added to it such as boiling point elevation, freezing point depression, and vapor pressure lowering.|
For certain types of aqueous solutions of sparingly soluble electrolytes, an equilibrium will be established at low concentration between the dissolved ions and undissolved solute or precipitate which can be quantatively described using the solubility product corresponding to particular ion pairs.
If you do not know this material backwards and fowards, you will suffer on the MCAT. The topic of Solutions equals any other in importance for the MCAT. Nearly every exam will require you to apply this material multiple times. Practically guaranteed, you will see something about colligative properties and something from heterogeneous solution equilibria. Do not neglect this material. Solutions will be on the test in a major way.