Enthalpy

define enthalpy change of formation

enthalpy change that takes place when 1 mole of compound formed from elements under standard conditions

define enthalpy change of combustion

enthalpy change when 1 mole of substance reacts completely with oxygen under standard conditions

define enthalpy change of neutralisation

enthalpy change when acid reacts with base to form 1 mole of water under standard conditions

define average bond enthalpy

when bond in mol of gaseous atoms break by homolytic fission

standard conditions

100 kPa

298 K

define enthalpy of atomisation

enthalpy change that takes place when 1 mole of gaseous atoms are formed from the element in it's standard form in standard conditions

define first electron affinity

enthalpy change when 1 electron added to each atom in 1 mole of gaseous atoms to form gaseous 1- ions

define enthalpy of solution

enthalpy change when 1 mole of solute dissolves in solvent

define lattice enthalpy

enthalpy change when 1 mole of ionic compound formed from its gaseous ions under standard conditions

define enthalpy of hydration

enthalpy change when 1 mole of gaseous ions dissolve in water to form 1 mole of aqueous ions

affect of ionic size + charge on lattice enthalpy

-as ionic size increases = less - lattice enthalpy

(radius increases so attraction decreases)

-as ionic charge increases = more - lattice enthalpy

(attraction between ions increase)

affect of ionic size + charge on hydration enthalpy

-as ionic size increases = less - hydration enthalpy

-as ionic charge increases = more - hydration enthalpy