Question

Order the following compounds according to their expected lattice energies: AlBr3,MgBr2, LiBr, and CaO. Rank from largest to smallest lattice energy. To rank items as equivalent, overlap them.

Answer 1

Explanation:

Lattice energy is defined as the energy released when formation of 1 mole of an ionic compound occurs due to the combination of its constituent ions.

Also, lattice energy is inversely proportional to the distance between the cation and anion. And, when we move down a group then there occurs an increase in the atomic radii of the atoms.

This means that smaller is the ionic distance between the cation and anion, more will be the lattice energy between the atoms.

Hence, given compounds are ranked from largest to smallest lattice energy as follows.

        $AlBr_{3}$ > CaO > $MgBr_{2}$ > LiBr