Problem

Assertion : Increasing order of covalent character among given compounds is

\text{HgCl}_2 < \text{CdCl}_2 < \text{ZnCl}_2

. Reason : Order of size of cations is

\text{Zn}^{2+} < \text{Cd}^{2+} < \text{Hg}^{2+}