The average Xe - F bond energy is 34 kcal/mol, first I.E. of Xe is 279 kcal/mol, electron affinity of F is 85 kcal/mol and bond dissociation energy of F2 is 38 kcal/mol. Then, the enthalpy change for the reactionXeF4 →  Xe+ + F- + F2 + F will be