van 't Hoff Factor ($$i$$)

$$i = \frac{\text{Normal (Theoretical) Molar Mass}}{\text{Observed (Experimental) Molar Mass}} = \frac{\text{Observed Colligative Property}}{\text{Calculated Colligative Property}} = \frac{\text{Total number of moles of particles after association/dissociation}}{\text{Number of moles of particles before association/dissociation}}$$

Concept: Accounts for the extent of association or dissociation of solute particles in a solution to correct colligative property calculations.