Question

arrange NaCl, MgCl₂ and AlCl₃ in inc. order of covalent character

Answer 1

According to fajan rule Covalent character depends on the size of cation and ion.
1. The larger the size of the anion more is the covalent character associated with compound
2. The smaller the size of the cation more is the covalent character.

Thus order on the basis of the fajan rule i.e
NaCl < MgCl2 < AlCl3

Reason : Al3+ size is smaller cation due to high + charge whereas Mg2+ smaller than Na+
Thus, smaller the size of the cation more is the covalent character.