Consider an ionic compound, MX2, composed of generic metal M and generic, gaseous halogen X.

Question

The enthalpy of formation of MX2 is ΔHf° = –799 kJ/mol.
The enthalpy of sublimation of M is ΔHsub = 157 kJ/mol.
The first and second ionization energies of M are IE1 = 785 kJ/mol and IE2 = 1451 kJ/mol. The electron affinity of X is ΔHEA = –349 kJ/mol.
The bond energy of X2 is BE = 157 kJ/mol.

Answer 1

What's the Question? If it's Crystal Lattace Energy, you need to review Born-Haber Cycle.

Answer 2

It is to Determine the lattice energy of MX2.