Final answer:
The standard enthalpy change of a reaction is the enthalpy change when all reactants and products are at a specific temperature. Enthalpy is the heat content of a system at constant pressure.
Chemists measure changes in enthalpy of chemical systems as reactants are converted into products.
Step-by-step explanation:
The standard enthalpy change of a reaction is the enthalpy change that occurs when all reactants and products are at a specific temperature.
Enthalpy (H) is the heat content of a system at constant pressure. Chemists measure changes in enthalpy of chemical systems as reactants are converted into products.
The heat that is absorbed or released by a reaction at constant pressure is the same as the enthalpy change, symbolized as ΔH.