Enthalpy OCR A definitions

first ionisation energy

to remove 1 mol of electrons from 1 mol of gaseous atoms

first electron affinity

Enthalpy change to form 1 mol of gaseous 1- ions from 1 mol of gaseous atoms

Enthalpy change of formation

Enthalpy change when 1 mole of a compound is formed from its elements in their standard states under standard conditions

enthalpy change of atomisation

enthalpy change to form 1 mol of gaseous atoms from its elements

Lattice enthalpy

Enthalpy change when 1 mole of a solid ionic compound is formed from its gaseous ions

Enthalpy change of hydration

Enthalpy change to convert 1 mole of gaseous ions to 1 mol of aqueous ions

Enthalpy change of solution

Enthalpy change when 1 mole of a solute is dissolved in water