Problem- Given the following information for magnesium, magnesium oxide and oxygen, compute the second electron affinity of oxygen.

1st electron affinity for oxygen is -141 kJ/mol

1st ionization energy for Mg +738 kJ/mol

2nd ionization energy for Mg +1450 kJ/mol

Delta H sublimation for Mg +148 kJ/mol

Bond dissociation energy for O2 +499 kJ/mol

Delta H formation of MgO -602 kJ/mol

Delta H lattice- +3890 kJ/mol