 ΔG from equilibrium const.

 
The Gibbs free energy of reaction can be calculated from an equilibrium constant by the use of the relationsip ΔG=RT⋅ln(k)
 
It is important not to confuse the equilibrium constant with a rate constant of reaction, since they can both be represented by the letter k. If the enthalpy of reaction is also either measured or otherwise known, then the entropy of reaction can also be calculated by the equation ΔG=ΔH+TΔS To calculate kinetics such as the rate of reaction, the avtivation energy (rather than the total energy change of reaction) is required.  