Answer the following:
(a) Define lattice enthalpy.
(b) What are the important consequences of lattice enthalpy?

Explanation

(a) The lattice enthalpy of an ionic solid is defined as the energy required to completely separate one mole of a solid ionic compound into gaseous constituent ions.
(b) The important consequences of lattice enthalpy are :
(i) The greater the lattice enthalpy, more the stability of ionic compound.
(ii) The lattice enthalpy is greater for ions of higher charge and smaller radii.
(iii) The lattice enthalpies affect the solubilities of ionic compounds.