Energetics 1/2 definitions

Standard enthalpy of reaction

The enthalpy change when the number of moles of the substance in the equation as written react under standard conditions of 100kPa and 298K.

Standard enthalpy of formation

The enthalpy change when 1 mole of a compound is formed from its elements, in their standard states under standard conditions of 100kPa and 298K

Standard enthalpy of combustion

The enthalpy change when one mole of a substance is completely burnt in excess oxygen under standard conditions of 100kPa and 298K

Standard enthalpy of atomisation

The energy required when 1 mole of gaseous atoms is formed from the element in its standard state at 100kPa and 298K

Standard enthalpy of neutralisation

The enthalpy change when one mole of water is produced by the neutralisation of a solution of an acid by excess base under standard solutions, with all solutions of concentration 1 moldm-3

Bond energy

Bond energy is the energy required to break 1 mole of covalent bonds when substances are in their gas state.

Lattice enthalpy

The energy released when 1 mole of solid ionic compound is formed from its gaseous ions at 298K and 100kPa

Enthalpy of hydration

The enthalpy change when 1 mole of gaseous ions is completely surrounded by water molecules under standard conditions

Enthalpy of solution

The enthalpy change when 1 mole of solid is dissolved in sufficient solvent to give an infinitely dilute solution

Electron affinity

The enthalpy change when 1 mole of gaseous atoms gain 1 mole of electrons to form one mole of gaseous 1- ions.