Calculateur d'Énergie Libre de Gibbs — Formule

Gibbs Free Energy

Formula

ΔG = ΔH − TΔS

Where:

  • ΔG = Gibbs free energy change (kJ)
  • ΔH = enthalpy change (kJ)
  • T = temperature (K)
  • ΔS = entropy change (J/K, converted to kJ/K by dividing by 1000)

    • If ΔG < 0, the reaction is spontaneous. If ΔG > 0, it is non-spontaneous. If ΔG = 0, the system is at equilibrium.

    Exemple Résolu

    A reaction with ΔH = -100 kJ and ΔS = -50 J/K at 298 K.

    1. ΔG = ΔH - TΔS
    2. ΔG = -100 - (298 × (-50)/1000)
    3. ΔG = -100 - (-14.9)
    4. ΔG = -100 + 14.9
    5. ΔG = -85.1 kJ (spontaneous)