Gce Model Questions Vol1 2018 Chemistry Question 20

Using the data below, apply a Born-Haber cycle to determine the enthalpy of sublimation of sodium metal, \( \Delta H_{\text{sub}}(\mathrm{Na}) \). Data (all per mole of substance unless stated): sublimation of solid chlorine, \( \Delta H_{\text{sub}}(\mathrm{Cl_2(s)}) = 58\) kJ mol\(^{-1}\); bond dissociation energy, \( D(\mathrm{Cl-Cl}) = 242\) kJ mol\(^{-1}\); ionisation energy of Na, \( IE(\mathrm{Na}) = 496\) kJ mol\(^{-1}\); electron affinity of chlorine, \( EA(\mathrm{Cl}) = -349\) kJ mol\(^{-1}\); lattice energy of NaCl, \( U_{\text{latt}}(\mathrm{NaCl}) = -787\) kJ mol\(^{-1}\); standard enthalpy of formation of NaCl(s), \( \Delta H_f^{\circ}(\mathrm{NaCl}) = -411\) kJ mol\(^{-1}\). Calculate \( \Delta H_{\text{sub}}(\mathrm{Na}) \) in kJ mol\(^{-1}\).