Knowing the electron gain enthalpy values for O → O– and O → O²^– as –141 and 702 kJ mol^–1 respectively, how can you account for the formation of a large number of oxides having O^2– species and not O^–?

Question

Philoid · Accepted Answer

Stability of an ionic compound depends on its lattice energy. More the lattice energy of a compound, more stable it will be. Lattice energy is directly proportional to the charge carried by an ion. When a metal combines with oxygen, the lattice energy of the oxide involving O^2- ion is much more than the oxide involving O^- ion. Hence, the oxide having O^2-ions are more stable than oxides having O^-. Hence, we can say that formation of O^2- is energetically more favorable that formation of O^-.

Knowing the electron gain enthalpy values for O → O– and O → O2– as –141 and 702 kJ mol–1 respectively, how can you account for the formation of a large number of oxides having O2– species and not O–?(Hint: Consider lattice energy factor in the formation of compounds).

Knowing the electron gain enthalpy values for O → O– and O → O²^– as –141 and 702 kJ mol^–1 respectively, how can you account for the formation of a large number of oxides having O^2– species and not O^–?
(Hint: Consider lattice energy factor in the formation of compounds).