Although molarity is the most common type of solution concentration used in general chemistry, there are several different ways to compare the relationship between solute and solvent.

Some have very specialized uses, but you should be familiar with these four:

1. molality (m) = moles solute / Kg solvent
 
Colligative properties depend on the number of particles of a substance involved. Chemists do calculations dealing with changing vapor pressure, boiling point elevation, and freezing point depression in solutions. A solution concentration that compares moles of solute and kilograms of solvent is most useful in these calculations.