AS˚ <0 at 298 K, since ΔH<0 and ΔG >0. An endothermic reaction is carried out under standard conditions. The equilibrium constant, Keq, for the reaction at 298 K is Keq = 3.55 x 107. Which of the following is true about the sign of ΔGº for the reaction? ΔG°> 0 because Keq is much greater than 1.