Enthalpy definitions Flashcards
enthalpy change
heat energy transferred in a reaction at constant pressure
standard enthalpy of formation
enthalpy change when 1 mole of a compound is formed from its elements in standard states, standard conditions
standard enthalpy of combustion
enthalpy change when 1 mole of a compund is completely burned in oxygen, standard states, standard conditions
bond dissociation enthalpy
enthalpy change when 1 mole of covalent bonds are broken in gaseous state
enthalpy of neutralisation
enthalpy change when 1 mole of water is formed in reaction between acid & alkali, standard conditions
1st ionisation energy
enthalpy change when each atom in 1 mole gaseous atoms loses 1 e- to form 1 mole gaseous 1+ ions
1st electron affinity
enthalpy change when each atom in 1 mole gaseous atoms gains 1 e- to form 1 mole gaseous 1- ions
enthalpy of atomisation
enthalpy change when 1 mole gaseous atoms produced from an element in its standard state under standard conditions
hydration enthalpy
enthalpy change when 1 mole gaseous ions become hydrated (dissolve in water, form 1 mole aqueous ions in aqueous solution)
enthalpy of solution
enthalpy change when 1 mole ionic solid dissolves in enough water that dissolved ions don’t interact
lattice enthalpy of formation
enthalpy change when 1 mole solid ionic compound formed from constituent gaseous ions
lattice enthalpy of dissociation
enthalpy change when 1 mole solid ionic compound broken up into constituent gaseous ions
enthalpy of vapourisation?
enthalpy change when 1 mole liquid -> gas, standard conditions
enthalpy of fusion?
enthalpy change when 1 mole solid -> liquid
mean bond enthalpy
enthalpy change when 1 mole gaseous molecules each breaks a covalent bond to form 2 free radicals, averaged over range of compounds