Question

Based on the lattice energy and other considerations, which of the following alkali metal chloride is expected to have highest melting point?

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

Answer 1

The correct option is B $NaCl$

On the basis of lattice energy, the melting point decreases in the alkali group as lattice energy decreases with the increase of the atomic number. However, $LiCl$ has covalent character due to very small size of $L{i}^{+}$ ion. Hence, melting point of $NaCl$ is highest amongst the above chlorides.