Calculate the lattice energy of Na2O for the following data:
Ionization energy of Na(g):::495kj/mol
Electron affenity of O(g) for 2e-:::603 kj/mol
Energy to vaporize Na(s):::109 kj/mol
O2(g) bond energy:::499 kj/mol
Energy change for the reaction 2 Na(s) + 1/2 O2(g)---->Na2O(s)