Question

The equation ΔHo = Σ ΔHfo (products) – Σ ΔHfo (reactants) stands for _______.

A. the First Law of Thermodynamics
B. the Second Law of Thermodynamics
C. Gibbs Free Energy Law
D. Hess’s Law
E. None of the Above

Answer 1

Answer:
Correct answer is D. The equation stands for Hess's law, i.e. the change of enthalpy in a chemical
reaction is independent of the pathway between the initial and final states, and therefore calculated
as a difference between sum of enthalpy of formation of products and reactants.