HOW DO YOU CALCULATE OSMOLALITY?

The osmolality of solutions can be calculated from the following equation:

osmolality = SUM OF ALL (molality x n x f) OF EACH SOLUTE
n: number of particles that dissociated from the solute molecule.
f: osmotic coefficient of the solute

Osmolality is not used very often in physiology.

More information on the osmotic coefficient are given in the chapter on Osmolarity