Hess's law of constant heat summation is bases on

Explanation

The Hess's law states that - " The heat or the enthalpy of a chemical reaction depends upon the intial state of a reactants and final state of production and it is independent of the path followed by the reaction either in single step or in series ".
Explanation of Hess's law :
Consider the conversation of the reactant A into the final product C . Let `Delta_(r)H^(0)` be the enthalpy change for the direct conversion .
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The same conversion can be carried out in two stteps as,
`{:("Reaction","Enthalpy change"),(A to B," "Delta_(r )H_(1)^(0)),(B to C," "Delta_(r )H_(2)^(0)):}`
Then by Hess's law, enthalpy change is independent of the path of the reaction .