V

Van't Hoff Factor

i = measured / calculated (no dissociation)
Quick Reference
Formula / Notationi = measured / calculated (no dissociation)
Also Known AsVan't Hoff factor i, osmotic coefficient, dissociation factor, electrolyte factor

What is Van't Hoff Factor?

The van't Hoff factor (i) is a correction factor used in colligative property calculations to account for the fact that solutes may dissociate (electrolytes) or associate (some carboxylic acids) when dissolved. For non-electrolytes, i = 1. For strong electrolytes that fully dissociate, i equals the number of ions produced per formula unit. For weak electrolytes, i is between 1 and the maximum number of ions.

Formula & Notation

i = measured / calculated (no dissociation)

Other Names / Synonyms: Van't Hoff factor i, osmotic coefficient, dissociation factor, electrolyte factor

Properties & Characteristics

i = 1 for non-electrolytes. i = 2 for NaCl (Na⁺ + Cl⁻), KNO₃ (K⁺ + NO₃⁻). i = 3 for CaCl₂ (Ca²⁺ + 2Cl⁻), Na₂SO₄. i = 4 for AlCl₃, Na₃PO₄. Actual i < theoretical for concentrated solutions (ion pairing). Modified colligative equations: ΔT_b = i × K_b × m; π = i × MRT.

Uses & Applications

Calculating colligative properties of electrolyte solutions. Osmotic pressure of physiological solutions. Antifreeze (ethylene glycol) calculations. Boiling point elevation and freezing point depression. Pharmaceutical IV fluid formulation. Osmometry.

Safety Information

Theoretical factor — safety depends on specific electrolyte. Strong acids/bases (NaOH, HCl, H₂SO₄): highly corrosive.

Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.

Key Facts

Term Van't Hoff Factor
Formula i = measured / calculated (no dissociation)
Synonyms Van't Hoff factor i, osmotic coefficient, dissociation factor, electrolyte factor

Frequently Asked Questions

The van't Hoff factor (i) is a correction factor used in colligative property calculations to account for the fact that solutes may dissociate (electrolytes) or associate (some carboxylic acids) when dissolved. For non-electrolytes, i = 1. For strong electrolytes that fully dissociate, i equals the number of ions produced per formula unit. For weak electrolytes, i is between 1 and the maximum number of ions.

More "V" Terms

View all "V" terms →
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z