The correct options are
A ΔC∘p2=[cC∘p(C)+dC∘p(D)]×(T−298)
B ΔC∘p1=[aC∘p(A)+bC∘p(B)]×(298−T)
C ΔH∘T=[aC∘p(A)+bC∘p(B)]×(298−T)+ΔH∘298+[cC∘p(C)+dC∘p(D)]×(T−298)
D ΔH∘T=ΔH∘298+ΔC∘p(T−298)
(A) The expression for the heat capacity at constant pressure is ΔC∘p1=[aC∘p(A)+bC∘p(B)]×(298−T)
Thus, the option A is correct.
(B) The expression for the heat capacity at constant pressure is ΔC∘p2=[cC∘p(C)+dC∘p(D)]×(T−298)
Thus, the option B is correct.
(C) The expression for the enthalpy change is ΔH∘T=[aC∘p(A)+bC∘p(B)]×(298−T)+ΔH∘298+[cC∘p(C)+dC∘p(D)]×(T−298)
Thus, the option C is correct.
(D) The expression for the enthalpy change is ΔH∘T=ΔH∘298+ΔC∘p(T−298)
Thus, the option D is correct.