Answer
Yes.
Work Step by Step
Standard enthalpy of a compound is the energy (per mole of compound) that would be necessary to take every element in the compound from elemental form into compound form. If one defines energy in elemental form to be 0, energy while in the compound is the standard enthalpy of formation. Because of this, Hess's law works: It's basically just calculating the difference in energy between the two sides of the reaction.
