To calculate the enthalpy change required to ionize 2 moles of magnesium atoms to form Mg2+ ions, we need to consider both the first and second ionization energies.First ionization energy is the energy required to remove one electron from each atom in 1 mole of gaseous atoms to form 1 mole of gaseous 1+ ions. In this case, the first ionization energy of magnesium is 737 kJ/mol.Second ionization energy is the energy required to remove one electron from each atom in 1 mole of gaseous 1+ ions to form 1 mole of gaseous 2+ ions. In this case, the second ionization energy of magnesium is 1450 kJ/mol.To ionize 2 moles of magnesium atoms to form Mg2+ ions, we need to consider both ionization energies for 2 moles:Enthalpy change for first ionization of 2 moles of Mg:H1 = first ionization energy number of moles H1 = 737 kJ/mol 2 moles = 1474 kJEnthalpy change for second ionization of 2 moles of Mg:H2 = second ionization energy number of moles H2 = 1450 kJ/mol 2 moles = 2900 kJTotal enthalpy change for ionizing 2 moles of Mg to Mg2+ ions:H_total = H1 + H2H_total = 1474 kJ + 2900 kJ = 4374 kJTherefore, the enthalpy change required to ionize 2 moles of magnesium atoms to form Mg2+ ions is 4374 kJ.