basic

Gibbs-Helmholtz Equation (Temperature Effect on ΔG) Calculator

ΔG(T) = ΔH − T·ΔS — assuming ΔH and ΔS roughly constant.

Compute the Gibbs free-energy change ΔG of a reaction at any user-chosen temperature T from the standard enthalpy ΔH and entropy ΔS using the Gibbs-Helmholtz approximation ΔG(T) = ΔH − T·ΔS (kJ/mol). Also reports the spontaneity-flip temperature T_flip = ΔH/ΔS where ΔG = 0.

Dr. Helena Ortiz By Dr. Helena Ortiz
Published Last reviewed 1 min read

Inputs

kJ/mol
J/(mol·K)
K

Results

Enter values and click Calculate to see results.
Was this helpful?

How to use this calculator

  1. Fill in the inputs above using the units you already have.
  2. Values update automatically as you type — no submit button needed.
  3. Hover any result row for the underlying formula and intermediate values.

Formula

ΔG(T) = ΔH − T·ΔS; T_flip = ΔH / ΔS.

In depth

Compute the Gibbs free-energy change ΔG of a reaction at any user-chosen temperature T from the standard enthalpy ΔH and entropy ΔS using the Gibbs-Helmholtz approximation ΔG(T) = ΔH − T·ΔS (kJ/mol). Also reports the spontaneity-flip temperature T_flip = ΔH/ΔS where ΔG = 0.