Energy Definitions
It should be noted that many of the energy definitions can be considered in the reverse direction with a corresponding change of sign for the energy.
e.g. Bond formation = exothermic ΔH negative, bond cleavage = endothermic ΔH positive
Standard enthalpy of vaporisation: The energy required to vaporise one mole of a liquid.
Enthalpy of atomisation: The energy required to produce one mole of gaseous atoms from an element in its standard state.
Bond dissociation enthalpy: The energy change when one mole of a specific bond is broken or created under standard conditions.
Standard bond enthalpy: The average energy change when one mole of a specific type of bond is broken or created under standard conditions.
Enthalpy of Combustion: The energy released when one mole of a compound is burned in excess oxygen.
Standard enthalpy of formation: The energy change when one mole of a compound is formed from its constituent elements in their standard states under standard conditions.
Standard enthalpy of solution: The energy change when one mole of a substance is dissolved in an infinite amount of water under standard conditions.
Standard dehydration enthalpy: The energy change when a particle is taken from infinite separation in the gaseous state to its position in an aqueous lattice.
Electron affinity: The enthalpy change when one mole of gaseous atoms accepts a mole of gaseous electrons under standard conditions.
Ionisation energy: The energy required to produce one mole of gaseous ions from one mole of gaseous atoms by removal of one mole of electrons.
Lattice enthalpy: The energy change when one mole of an ionic substance is broken into its constituent ions at infinite separation.