To calculate the lattice energy of MgO using the Born-Haber cycle, we need to consider the following steps:1. Sublimation of Mg s to Mg g : H_sub = +1472 kJ/mol2. Ionization of Mg g to Mg^+ g : H_IE1 = +738 kJ/mol3. Ionization of Mg^+ g to Mg^2+ g : H_IE2 = +1450 kJ/mol4. Electron affinity of O g to O^- g : H_EA1 = -141 kJ/mol5. Formation of MgO s from Mg^2+ g and O^- g : H_f = -601 kJ/molThe Born-Haber cycle states that the sum of all these enthalpy changes should be equal to the lattice energy U of MgO:U = H_sub + H_IE1 + H_IE2 + H_EA1 + H_fSubstitute the given values:U = +1472 kJ/mol + +738 kJ/mol + +1450 kJ/mol + -141 kJ/mol + -601 kJ/mol U = 3919 kJ/mol - 742 kJ/molU = 3177 kJ/molTherefore, the lattice energy of MgO is 3177 kJ/mol.