Consider the following information. the lattice energy of cscl is δ h lattice = − 657 kj/mol. the enthalpy of sublimation of cs is δ h sub = 76.5 kj/mol. the first ionization energy of cs is ie 1 = 376 kj/mol. the electron affinity of cl is δ h ea = − 349 kj/mol. the bond energy of cl 2 is be = 243 kj/mol. determine the enthalpy of formation, δ h f , for cscl ( s ) .