Question

Among $LiCl,RbCl,$ $BeC{l}_2$ and $MgC{l}_2$ which two are the highest and the lowest ionic compounds?

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

Answer 1

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

Rb has the largest ionic radius and thus RbCl has the smallest lattice energy. Also, Be has the smallest ionic radii and thus $BeC{l}_2$ has the highest lattice energy. Therefore RbCl has the highest ionic strength and $BeC{l}_2$ has the weakest ionic strength.