AQA Unit 5 Chemisty Definitions ( Extra Special)

GLOSSARY OF USEFUL TERMS FOR UNIT 5

Enthalpy of Formation: enthalpy change when one mole of a compound is formed from its constituent elements. All reactants and products in their standard states.

First Ionisation Enthalpy: The standard enthalpy change when one mole of electrons is removed from one mole of gaseous atoms which is therefore converted to one mole of gaseous ions, each with a single positive charge.

Second Ionisation Enthalpy:The standard enthalpy change is when one mole of electrons is removed from one mole of gaseous ions with a single positive charge which is therefore converted to one mole of ions with two positive charges,

Enthalpy of Atomisation of an Element :The enthalpy change that accompanies the formation of one mole of gaseous atoms from the element in its standard state, under standard conditions.

Enthalpy of Atomisation of a Compound: enthalpy change when one mole of a compound in its standard state is converted into free gaseous atoms

First Electron Affinity:The standard enthalpy change when one mole of electrons is added to one mole of gaseous atoms which is converted to one mole of gaseous ions, each with a single negative charge

Second Electron Affinity: The enthalpy change when one mole of electrons is added to one mole of gaseous ions with a single negative charge, to form one mole of ions with two negative charges.

Bond Dissociation Enthalpy:The enthalpy change when one mole of gaseous molecules each breaks a covalent bond to form two free radicals

Lattice Enthalpy of Formation: Enthalpy change when one mole of an ionic compound is formed from its constituent gaseous ions

Lattice Dissociation Enthalpy: Enthalpy change when one mole of an ionic compound is completely dissociated into its constituent gaseous ions

Enthalpy of Hydration: Enthalpy change when one mole of gaseous ions is added to an excess of water

Enthalpy of Solution: Enthalpy change when one mole of an ionic compound is completely dissolved in an excess of water

Entropy: a measure of the degree of disorder in…