what is enthalpy
Enthalpy is the heat content of a chemical system. The molar enthalpy of reaction (Hrxn) is the amount of heat transferred during a reaction. It is reported in kilojoules per mole of reactant. A reaction that produces heat is exothermic and has a negative Hrxn.A reaction that absorbs heat is endothermic and has a positive Hrxn.he molar enthalpy of reaction (Hrxn) is the amount of heat transferred during a reaction. It is reported in kilojoules per mole of reactant. A reaction that produces heat is exothermic and has a negative Hrxn. A reaction that absorbs heat is endothermic and has a positive Hrxn.