The ionic crystals have the following characteristics:
(i) The heats of vapourisation of ionic crystals are high.
(ii) The vapour pressure of ionic crystals at oridnary temperature are very low.
(iii) The melting and boiling points of ionic crystals are very high.
(iv) Ionic crystals are hard and brittle.
(v) Ionic crystals are insulators in the soild state.
(vi) Ionic crystals are soluble in water and also in other polar solvents.
(vii) Ionic solids are good conductors when dissolved in water.