Question

The structures of $BC{l}_3$ and $AlC{l}_3$ in their liquid states are, respectively:

• A. Monomer and monomer
• B. Dimer and dimer
• C. Dimer and monomer
• D. Monomer and dimer

Answer 1

The correct option is D Monomer and dimer

In the solid state, $AlC{l}_3$ has an ionic structure, but in the molten form (or liquid phase) it has a dimeric structure. In $BC{l}_3$, the electron deficiency is compensated by the formation of $p_{\pi }-p_{\pi }$ bonds within the molecule so $BC{l}_3$ does not form dimeric structure.