The bonds in an ionic compound are stronger than the bonds in a molecular compound; since the bond is stronger, more energy, in the form of heat, is needed to break it. This is because in an molecular compound, covalent bonds are present, which is the sharing of electrons between atoms, while in an ionic compound, ionic bonds are present, which means electrons are taken from one atom and given to another atom, which takes more energy to reverse than covalent bonds do.
