Skip to main content
Chemistry LibreTexts

Colligative Properties

  • Page ID
    1589
  • Colligative properties are the physical changes that result from adding solute to a solvent. Colligative Properties depend on how many solute particles are present as well as the solvent amount, but they do NOT depend on the type of solute particles, although do depend on the type of solvent.

    • Anomalous Colligative Properties (Real Solutions)
      Anomalous colligative properties are colligative properties that deviate from the ideal colligative behavior. It is quantified by the introduction of the Van't Hoff factor.
    • Boiling Point Elevation
      The boiling points of solutions are higher than that of the pure solvent. This effect is directly proportional to the molality of the solute.
    • Freezing Point Depression
      The freezing points of solutions are all lower than that of the pure solvent. The freezing point depression is directly proportional to the molality of the solute.
    • Osmotic Pressure
      The osmotic pressure of a solution is the pressure difference needed to stop the flow of solvent across a semipermeable membrane. The osmotic pressure of a solution is proportional to the molar concentration of the solute particles in solution.
    • Vapor Pressure Lowering
      The vapor pressure of a solvent in a solution is always lower than the vapor pressure of the pure solvent. The vapor pressure lowering is directly proportional to the mole fraction of the solute.