Chemistry

Problem

The theoretical lattice enthalpies, based on the ionic model, of sodium chloride and magnesium oxide are shown below.

Compound	$\Delta H_{\text{lat}}^{\ominus} / \text{kJ mol}^{-1}$
NaCl	770
MgO	3795

Explain why magnesium oxide has the higher lattice enthalpy compared with sodium chloride.