<!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}-->The free-energy change of a reaction (ΔG) tells us if the reaction can occur spontaneously.It is also known as gibbs free energy
In the general reaction aA + bB <--> cC + dD,
where a, b, c, and d are the number of molecules of A, B, C, and D participating, the equilibrium constant is given by
Keq = [C]c[D]d/[A]a[B]b
ΔG=ΔG°+RT ln Keq
when reaction is in equilibrium ΔG=0
so
ΔG°' = -RT ln K'eq
which is the actual free energy change for a reaction at 298k and ph7 given the concentrations of each reactant