F325 OCR (A) A Level Enthalpy Change Definitions

(Standard) enthalpy change of atomisation

The enthalpy change that takes place when one mole of gaseous atoms forms from the element in its standard state.

(Standard) enthalpy change of combustion

The enthalpy change that takes place when one mole of a substance reacts completely with oxygen under standard conditions, all reactants and products being in their standard states.

(Standard) enthalpy change of formation

The enthalpy change that takes place when one mole of a compound is formed from its constituent elements in their standard states under standard conditions.

(Standard) enthalpy change of hydration

The enthalpy change that takes place when one mole of isolated gaseous ions is dissolved in water, forming one mole of aqueous ions, under standard conditions.

(Standard) enthalpy change of neutralisation

The energy change that accompanies the neutralisation of an aqueous acid by an aqueous base to form one mole of H2O(l), under standard conditions.

(Standard) enthalpy change of reaction

The enthalpy change that accompanies a reaction in the molar quantities expressed in a chemical equation under standard conditions, all reactants and products being in their standard states.

(Standard) enthalpy change of solution

The enthalpy change when 1 mole of an ionic substance dissolves in water to give a solution of infinite dilution.

Electron Affinity

The energy released when 1 mole of gaseous atoms each acquire an electron to form 1 mole of gaseous 1⁻ ions

Lattice Formation Enthalpy

The enthalpy change when 1 mole of an ionic solid is formed from its gaseous ions.

First Ionisation Energy

the energy required to remove one mole of electrons from one mole of gaseous atoms to produce 1 mole of gaseous ions each with a charge of 1⁺.