Question

Amongst $LiCl$, $RbCl$, $BeC{l}_2$ and $MgC{l}_2$, maximum and minimum ionic character will be shown by the compounds:

• A. $LiCl$, $MgC{l}_2$
• B. $RbCl$, $BeC{l}_2$
• C. $RbCl$, $MgC{l}_2$
• D. $MgC{l}_2$, $BeC{l}_2$

Answer 1

The correct option is B $RbCl$, $BeC{l}_2$

According to Fajans' rule, smaller the size of the cation and larger the size of the anion, greater is the covalent character. Here, the largest cation is $R{b}^{+}$ and the smallest cation is $B{e}^{2+}$.
$RbCl$ is the most ionic $BeC{l}_2$ is the least ionic.