lattice enthalpy Flashcards
lattice enthalpy
measure of the strength of ionic bonding in a giant ionic lattice
lattice dissociation enthalpy
the enthalpy change when one mole of a solid ionic compound is completely dissociated into its gaseous constituent ions under standard conditions (endothermic)
lattice formation enthalpy
the enthalpy change when one mole of a solid ionic compound is formed from its gaseous constituent ions under standard conditons
(exothermic)
atomisation enthalpy
the energy required for the formation of one mole of gaseous atoms from an element under standard conditions
enthalpy of electron affinity
the enthalpy change when one mole of electrons is aded to a mole of gaseous atoms to form one mole of gaseous 1- ions under standard conditions
hess law
the enthalpy change of a reaction is independent of the route taken
born haber cycles
allow enthalpy changes to be determined when they cannot be measured directly
perfect ionic model assumptions
all the ions are perfectly spherical
charge is distributed evenly throughout the ion
the ions display no covalent character
enthalpy of hydration
the enthalpy change when one mole of gaseous ions is dissolved in water to form one mole of aqueous ions under sc
- measure of attraction between ions and water molecules in solution
enthalpy of solution
the enthalpy change when one mole of ionic solid is dissolved in water to infinite dilution so that the ions no longer interact under SC
factors affected enthalpy of hydration
attractions are stronger with smaller ions and with ions of a greater charge
hydration enthalpy decreases as you move down a group
factors affecting lattice dissociation enthalpy
increases with decreasing ionic radius
increases with increasing charge
- ions form a stronger attraction so the energy required for dissociation is larger
