Born-Haber Cycles

• Enthalpy of lattice dissociation = The enthalpy change when one mole of an ionic compound is separated into its component gaseous ions.
• Enthalpy of lattice formation = The enthalpy change when one mole of an ionic compound is formed from its constituent ions in the gaseous state.
• Enthalpy of formation = The enthalpy change when one mole of a compound is formed from its elements when all reactants and products are in their standard states under standard conditions.
• First ionisation energy = The energy change when one mole of electrons is removed from one mole of gaseous atoms to form one mole of gaseous ions with a single positive charge.
• Second ionisation energy = The energy change when one mole of electrons is removed from one mole of gaseous ions with a single positive charge to form one mole of gaseous ions with a 2+ positive charge.
• Third ionisation energy = The energy change when one mole of electrons is removed from one mole of gaseous ions with a  2+ positive charge to form one mole of gaseous ions with a 3+ positive charge.
• Enthalpy of atomisation = The enthalpy change for the formation of one mole of gaseous atoms from the element in its standard state.
• Bond enthalpy = The enthalpy change when one mole of a covalent bond is broken under standard conditions in the gaseous state.
• First electron affinity = The enthalpy change when one mole of gaseous atoms forms one mole of negative ions with a single negative charge.
• Second electron affinity = The enthalpy change when one mole of gaseous ions with a single negative charge forms one mole of negative ions with a double negative charge.
• Enthalpy of solution = The enthalpy change when one mole of a solute dissolves in water.
• Enthalpy of hydration = The enthalpy change when one mole of gaseous ions is converted into one mole of aqueous ions.
• The perfect ionic model allows the calculation of the lattice enthalpy based on two assumptions:

  1. The bonding in the compound is 100% ionic.
  2. The ions are regarded as point charges or perfect spheres and are not distorted.