Calculate the electron affinity of oxygen atom in gaining two electrons to give the oxide ion O−2 from the following data.
Standard heat of formation of MgO(s)=−600 kJmol−1
Lattice energy of MgO(s)=−3860 kJmol−1
lonization energy of Mg(g) to give Mg+2 is +2170 kJmol−1
Dissociation energy of O2(g) is +494 kJmol−1
Heat of sublimation of Mg(s) is +150 kJmol−1