- 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.
