Gibbs Free Energy & Reaction Spontaneity Calculator (ΔG = ΔH - TΔS)
Calculate Gibbs free energy change (ΔG), predict thermodynamic reaction spontaneity, and determine the threshold crossover temperature via the fundamental Gibbs-Helmholtz relation.
Gibbs Free Energy Change (ΔG)
Calculator Inputs
Gibbs Free Energy Change (ΔG)
Entropy Term (T·ΔS in kJ/mol)
Spontaneity Crossover Temperature
Thermodynamically Spontaneous (ΔG < 0): The process is exergonic and occurs spontaneously in the forward direction.
Gibbs Free Energy Enthalpy vs Entropy Profile
Standard chemical thermodynamics tool for feasibility, equilibrium, and entropy-enthalpy driving forces.
Calculation Methodology
Gibbs-Helmholtz Equation: ΔG = ΔH - [ T * (ΔS / 1000) ]. Where ΔH is in kJ/mol, ΔS in J/(mol K), and T in Kelvin (K = °C + 273.15). If ΔG < 0, the reaction is thermodynamically spontaneous. Crossover Temperature: T_threshold = (ΔH * 1000) / ΔS.
Frequently Asked Questions
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