For 10 points, name this thermodynamic law which states that the enthalpy change of a reaction equals the enthalpy of the products minus that of the reactants, named for a Swiss-born Russian chemist.
This law explains why a catalyst does not alter the equilibrium position of a reaction. Given data such as electron affinity, heat of vaporization, and heat of ionization, this law is used in Born-Haber cycles to calculate the lattice energy of an ionic solid. This law can also be used to calculate heats of formation. It states that enthalpy is a state function, which is why it is known as the law of constant heat summation. For 10 points, name this thermodynamic law which states that the enthalpy change of a reaction equals the enthalpy of the products minus that of the reactants, named for a Swiss-born Russian chemist.
This law explains why a catalyst does not alter the equilibrium position of a reaction.
{Hess's} law [accept {law} of {constant heat summation} before it is mentioned]