additivity of heats of reaction lab answers m of individual heats, weighted by their proportions. Example Calculation: If: ΔH A = -500 kJ ΔH B = -300 kJ and the mixture contains 2 mol of X and 3 mol of Y, then: Expected total heat: ΔH total = (2 mol × ΔH A ) + (3 mol × ΔH B ) = (2 × -500) + (3 × -300) = -1000 - 900 = C Cyril Harber-Kub Nov 11, 2025