Relation between equilibrium constant, reaction quotient and Gibbs energy
The value of the equilibrium constant for a reaction does not depend on the rate of reaction.
· If a change in Gibbs free energy ΔGΔG is negative, then the reaction proceeds in the forward reaction with spontaneity.
· If a change in Gibbs free energy ΔGΔG is positive, the products of the forward reaction shall be converted to reactants with a non-spontaneous process.
· If the change in Gibbs free energy is zero, then the reaction is at equilibrium and there is no longer any free energy left to drive the reaction.
ΔG=ΔGo+RTlnQ
Where Q is Reaction Quotient. And Go is standard Gibbs free energy.
At equilibrium, when ΔGo=0 and Qc=Kc
ΔG=ΔGo+RTlnKc=0
from the above equation, from the values of ΔGo , the reaction spontaneity can be interpreted.