Question

Which of the following compounds will have the largest lattice energy?

• A. $AlB{r}_3$
• B. $CaO$
• C. $LiBr$
• D. $MgB{r}_2$

Answer 1

The correct option is A $AlB{r}_3$

Among the cations, $A{l}^{3+},C{a}^{2+},L{i}^{+}$ and $M{g}^{2+}$, $A{l}^{3+}$ has the highest charge. Hence, $AlB{r}_3$ has the highest lattice energy. The lattice energy is directly proportional to the charge on the ion and inversely proportional to the size of the ion.