The magnitude of G measures how far a reaction is from equilibrium. The larger the value ofG, the further the reaction is from equilibrium and the further the reaction must shift to reach equilibrium. In reactions in which enthalpy is favorable and entropy is unfavorable, the reaction becomes less spontaneous (G increases) until eventually the reaction is not spontaneous (whenG > 0). As the magnitude ofGchanges, so does the equilibrium constant. K.