Question

Amongst $LiCl$, $RbCl$, $BeC{l}_2$ and $MgC{l}_2$, the compounds with the greatest and the least ionic character, respectively are:

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

Answer 1

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

According to Fajan's rule, molecule with smaller cation and large anion has higher covalent nature. $RbCl$ is most ionic in nature and $BeC{l}_2$ is covalent due to high polarisation power of $B{e}^{2+}$.