Question

if a reaction is at equilibrium the free energy change is

Answer 1

This means, of course, that if the total free energy G of a mixture of reactants and products goes through a minimum value as the composition changes, then all net change will cease— the reaction system will be in a state of chemical equilibrium. You will recall that the relative concentrations of reactants and products in the equilibrium state is expressed by the equilibrium constant. In this lesson we will examine the relation between the Gibbs free energy change for a reaction and the equilibrium constant