Answer :
A.) makes it possible to
calculate ΔH for complicated chemical reactions
Hess’s Law makes it possible to calculate ΔH for complicated chemical reactions. Moreover, the principle claims that the entire amount of “enthalpy” when the development or progression of a chemical reaction is complete whether the reactions are created in a single or numerous processes, it still changes. This law is now described as the principle of conservation of energy, and part of the thermodynamics law as the first.
Hess’s Law makes it possible to calculate ΔH for complicated chemical reactions. Moreover, the principle claims that the entire amount of “enthalpy” when the development or progression of a chemical reaction is complete whether the reactions are created in a single or numerous processes, it still changes. This law is now described as the principle of conservation of energy, and part of the thermodynamics law as the first.
You can add TriangleH for two or more thermochemical reaction to get the final heat of reaction