Hess' Law

Let's study a little bit of history:

In 1830, a Russian chemist and doctor known and Germain Henri Hess, formulate a law that it is still used today. It is called the Hess law.

According to Hess, the enthalpy change of a chemical process, only depend on the initial and final state, not on its pathway. The enthalpy change of the overall process is the sum of the enthalpy change of its individual steps.