Use the following data to calculate second electron affinity of oxygen for the process
O−(g)+e−(g)→O2−(g).
Heat of sublimation of Mg(s)=147.7kJ/mol
Ionisation energy of Mg(g) to form
Mg2+(g)=2189 kJ/mol
Bond dissociation energy for O2 =498.4 kJ/mol
First electron affinity of O(g)=−141 kJ/mol
Heat formation of MgO(s)=−601.7 kJ/mol
lattice energy of MgO=−3791 kJ/mol