s-Block

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

  1. LiCl
  2. NaCl
  3. KCl
  4. RbCl

Answer

In case of halides of alkali metals, melting point decreases going down the group because lattice enthalpies decreases as size of alkali metal increases. But LiCl has lower melting point in comparison to NaCl due to covalent nature. Thus, NaCl is expected to have the highest melting point among given halides.

The correct option is B.