Explain Hess s Law - SS1 Chemistry Energy Changes in Chemical Reactions Question

Hess's Law states that the total enthalpy change of a chemical reaction is independent of the pathway taken from the initial to the final state. In other words, the enthalpy change of a reaction depends only on the initial and final states and is not affected by the intermediate steps.

Hess's Law is used to calculate enthalpy changes of reactions by manipulating and combining known enthalpy changes of other reactions. This can be achieved by using a series of intermediate reactions whose enthalpy changes are known or can be determined.