Answer to Question #316490 in General Chemistry for John

Question

State that values of standard states of formation are important because these are

conveniently used to calculate changes in enthalpy, ΔH of many  reactions.  

Answer 1

Enthalpies (or heats) of formation are extremely useful in calculating reaction enthalpies. That is because any reaction can be visualized as taking place via a path in which first all the reactant compounds are converted to elements and then all the elements are converted in the product compounds.