Final answer:
The heat measured in the example is based on the experimental conditions of the calorimetry and the specific molar amounts reacting, while the enthalpy change is a standardized heat change per mole of reactants under standard conditions.
Step-by-step explanation:
The heat measured in the given calorimetry example for the exothermic reaction is the amount of heat released when specific amounts of the reactants (HCl and NaOH) react in an insulated environment. However, this heat value is contingent upon the molar quantities of the substances involved and the calorimeter's specific conditions that do not absorb any heat and prevent heat exchange with the surroundings.
On the other hand, enthalpy change (∆H) for a reaction is a thermodynamic quantity that represents the total heat change at constant pressure for the reaction scaled to per mole of reactant or product levels, often reported under standard conditions. For instance, the given equation NaOH (aq) + HCl(aq) → NaCl(aq) + H₂O(l) ∆H = -56 kJ reflects the enthalpy change for the reaction of one mole of HCl with one mole of NaOH, indicating that 56 kJ of heat is released per mole of reactants under standard conditions.