CE1 Summary of definitions

Standard enthalpy change of reaction

Energy change in chemical reaction when the molar quantities of reactants stated in the chemical equation react under standard conditions (ie 1 bar and 298K)

Standard enthalpy change of formation

Energy change when 1 mole of pure substance in specified state is formed from its constituent elements in their standard states under standard conditions (ie. 1 bar and 298K)

Standard enthalpy change of combustion

Energy released when 1 mole of substance is completely burnt in excess oxygen under standard conditions (use. 1 bar and 298K)

Standard enthalpy change of neutralisation

Energy change when acid and base react to form 1 mole of water under standard conditions (ie. 1 bar and 298K)

Standard enthalpy change of atomisation of element

Energy absorbed when 1 mole of gaseous atoms is formed from the element under standard conditions (ie. 1 bar and 298K)

Standard enthalpy change of atomisation of compound

Energy absorbed when 1 mole of compound is converted to gaseous atoms under standard conditions (ie 1 bar and 298K)

Bond energy

Average energy required to break 1 mole of X-Y bonds in gaseous state

Lattice energy

Energy released when 1 mole of solid ionic compound is formed from its constituent gaseous ions under standard conditions (ie. 1 bar and 298K)

First ionisation energy

Energy required to remove 1 mole of electrons from 1 mole of gaseous atoms to form 1 mole of singly positively charged gaseous ions

First electron affinity

Energy change when 1 mole of gaseous atoms acquires 1 mole of electrons to form 1 mole of singly negatively charged gaseous ions

Standard enthalpy change of hydration

Energy released when 1 mole of gaseous ions is dissolve in water to form 1 mole of aqueous ions under standard conditions (ie. 1 bar and 298K)

Standard enthalpy change of solution

Energy change when 1 mole of substance is completely dissolved in a solvent to form an infinitely dilute solution under standard conditions (ie. 1 bar and 298K)