enthalpy changes
standard conditions
298k and 100kPa
making bonds
exothermic = -ve
breaking bonds
endothermic = +ve
activation energy
minimum amount of energy particles must have in order to react successfully when they collide
average bond enthalpy
energy change when one mol of gaseous bonds is broken
hess's law
the enthalpy change for a reaction is independent of the route by which the reaction is achieved
enthalpy of formation
when 1 mol of a compound is formed from its reactants under standard conditions
enthalpy of neutralisation
energy when 1mol of H2O is produced by neutralising an acid
lattice enthalpy
energy change when 1 mol of an ionic lattice from its gaseous ions under standard conditions
first electron affinity
energy needed to add 1 mol of electrons to 1 mol of gaseous atoms to form 1 mol of gaseous 1 - ions
enthalpy of atomisation
energy change to produce 1 mol of seperate atoms in the gas phase
first ionisation energy
energy change to remove 1 mol of electrons from 1 mol of gaseous atoms to form 1 mol of gaseous 1 + ions
exo reactions
lattice, formation, first electron affinity
endo reactions
ionisation energy, atomisation, second electron affinity