Calculate the lattice enthalpy (?Hl° in kJ/mol) of the MF2 metal fluoride using the following data: Bond dissociation enthalpy of F2(g) = 159 kJ/mol Electron affinity of F = -328 kJ/mol Enthalpy of sublimation of M = 123 kJ/mol First ionization energy of M = 432 kJ/mol Second ionization energy of M = 604 kJ/mol Standard enthalpy of formation of MF2(s) = -399 kJ/mol