The enthalpy of formation of MX2 is ?Hf° = -829 kJ/mol. The enthalpy of sublimation of M is ?Hsub = 117 kJ/mol. The first and second ionization energies of M are IE1 = 717 kJ/mol and IE2 = 1433 kJ/mol. The electron affinity of X is EA = -319 kJ/mol. The bond energy of X2 is BE = 151 kJ/mol.