Question

Which of the following is the correct order of melting point?

• A. $LiCl<NaCl$
• B. $NaCl<KCl$
• C. $KCl<RbCl$
• D. All of the above

Answer 1

The correct option is A $LiCl<NaCl$

As we move down the group, lattice energy decreases. Hence, the melting point decreases.
However, due to polarisation of $C{l}^{-}$ ion by $L{i}^{+}$, $LiCl$ is highly covalent and hence it has a lower melting point than $NaCl$.