The molar heat capacities of A, B and C are in the ratio 1:2:3. The enthalpy change for the reaction A + B → C at temperature T 1 is ΔH 1 . Assuming that the heat capacities do not change with tempera

Question

The molar heat capacities of A, B and C are in the ratio 1:2:3. The enthalpy change for the reaction A + B → C at temperature T 1 is ΔH 1 . Assuming that the heat capacities do not change with temperature, the enthalpy change, ΔH 2 , at temperature T 2 (T 2 > T 1 ) will be

TestHub · Accepted Answer

The change in heat capacity, Δ C P , is calculated as: Δ C P = C P (C) - C P (A) - C P (B) Given the values, we have: Δ C P = 3 - 1 - 2 = 0 Since Δ C P = 0, the change in enthalpy Δ H remains constant regardless of temperature. The relationship between Δ H 2 and Δ H 1 at different temperatures T 2 and T 1 is given by: Δ H 2 = Δ H 1 + Δ C P (T 2 - T 1 ) As Δ C P = 0, it follows that Δ H 2 = Δ H 1 at any temperature. This corresponds to option (b).

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