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The standard enthalpy of combustion is the enthalpy change when one mole of a reactant completely burns in excess oxygen under standard thermodynamic conditions (although experimental values are usually obtained under different conditions and subsequently adjusted).he standard enthalpy of combustion is the enthalpy change when one mole of a reactant completely burns in excess oxygen under standard thermodynamic conditions (although experimental values are usually obtained under different conditions and subsequently adjusted).
The standard enthalpy change for the reaction. is 178.1 kJ. From the values for the standard enthalpies of formation of CaO (s) and CO 2 (g) given in Table 5.3, calculate the standard enthalpy of formation of CaCO 3 (s). SOLUTION The standard enthalpy change in the reaction is.