Home » Blog » Equation of the day Thermodynamic equation Whose equation is this? AnswerThis is Gibbs free energy of reaction This thermodynamic equation shows that the change in the enthalpy (H) of the system minus the product of the temperature (Kelvin) equals the change in the entropy (S) of the system.This is Gibbs free energy of reaction This thermodynamic equation shows that the change in the enthalpy (H) of the system minus the product of the temperature (Kelvin) equals the change in the entropy (S) of the system. Share this