delta_H at temperature T2 = delta_H at T1 + delta_Cp(T2 - T1). delta_Cp = sum(Cp products) - sum(Cp reactants). This allows calculation of enthalpy at non-standard temperatures. Similarly: delta_U(T2) = delta_U(T1) + delta_Cv(T2 - T1). If delta_Cp > 0, the reaction becomes more endothermic (or less exothermic) with increasing temperature. If delta_Cp < 0, it becomes more exothermic with increasing temperature. JEE rarely tests this directly but it appears in advanced problems.