Use the formula: ( i = dfrac{text{observed colligative property}}{text{calculated colligative property for a nonelectrolyte}} )
For freezing point depression: ( i = dfrac{Delta T_f}{K_f m} )
For boiling point elevation: ( i = dfrac{Delta T_b}{K_b m} )
For osmotic pressure: ( i = dfrac{pi}{MRT} )
For relative lowering of vapor pressure: ( i = dfrac{text{observed lowering}}{text{calculated lowering}} )
If the solute dissociates, use: ( i = 1 + (n – 1)alpha )
If the solute associates, use: ( i = 1 – alpha + dfrac{alpha}{n} )
Identify the number of particles formed per formula unit in solution
Determine the degree of dissociation or association if needed
Compare the measured colligative property with the expected value for a non-dissociating solute