Question

Which crystal has the largest lattice energy?

• A. $KCl$
• B. $MgO$
• C. $LiBr$
• D. $NaF$

Answer 1

The correct option is B $MgO$

Cationic and anionic charge in MgO is highest among KCL, LiBr, NaF

In MgO crystal $\left(M{g}^{2+}{O}^{2-}\right)$, Mg have +2 and O have -2 charge.

$LE=\frac{k{q}_1{q}_2}{(r^{+}+r^{-})}$

$LE\propto \frac{1}{\text{interionic distance}}$

$LE\propto q_1{q}_2$

Thus, MgO will have the highest energy.

Hence, the correct option is $\text{B}$.