∆G=∆H−T∆S Since ∆G=∆H−T∆S for an endothermic reaction, ∆H=+ve and at low temperature ∆S=+ve Hence ∆G=(+)∆H−T(+)∆S and if T∆S<∆H (at low temp) ∆G=+ve (non spontaneous) But at high temperature, reaction becomes spontaneous i.e. ∆G=− ve. because at higher temperature T∆S>∆H.