- For a spontaneously reaction to takes place, the system must has a negative free-energy change ΔG.
- Because changes in all (free energy - entropy and enthalpy) are related to each other by the following equation :
ΔG = ΔH-TΔS,
So ΔG becomes more negative when entropy (randomness) increases, i.e. when the products of a reaction are more disordered and less complex than the reactants.