Answer : The magnitude of the lattice energy for CsCl is, 667 KJ/mole
Explanation :
The steps involved in the born-Haber cycle for the formation of
:
(1) Conversion of solid calcium into gaseous cesium atoms.

= sublimation energy of calcium
(2) Conversion of gaseous cesium atoms into gaseous cesium ions.

= ionization energy of calcium
(3) Conversion of molecular gaseous chlorine into gaseous chlorine atoms.

= dissociation energy of chlorine
(4) Conversion of gaseous chlorine atoms into gaseous chlorine ions.

= electron affinity energy of chlorine
(5) Conversion of gaseous cations and gaseous anion into solid cesium chloride.

= lattice energy of calcium chloride
To calculate the overall energy from the born-Haber cycle, the equation used will be:

Now put all the given values in this equation, we get:


The negative sign indicates that for exothermic reaction, the lattice energy will be negative.
Therefore, the magnitude of the lattice energy for CsCl is, 667 KJ/mole