Question

Based on lattice energy and other considerations which one of the following alkali metal chlorides is expected to have the highest melting point.

• A. $LiCl$
• B. $NaCl$
• C. $KCl$
• D. $RbCl$

Answer 1

The correct option is B $NaCl$

Here the answer is option B

Although lattice energy of $LiCl$ higher than $NaCl$, but $LiCl$ is covalent in nature and $NaCl$ ionic thereafter, the melting point decreases as we move downin group $NaCl$ because the lattice energy decreases as a size of alkali metal atom increases.