Enthalpy change is the energy exchanged with surroundings measured at constant temperature
Enthalpy change of reaction is the enthalpy change when molar amounts react under standard conditions
Enthalpy change of formation is the enthalpy change when one mole of a substance is formed from its elements in standard states under standard conditions
Enthalpy change of combustion is the enthalpy change when one mole of a substance undergoes completecombustion under standard conditions
If the reaction equations are the same, then the enthalpy change of formation and combustion are the same
The enthalpy change of formation of elements is zero
