Question

The coordination number of Al in crystalline $AlC{l}_3$ is

• A. 3
• B. 6
• C. 2
• D. 1

Answer 1

The correct option is B 6

In this structure, $A{l}^{3+}$ exhibits octahedral geometry. Here each $A{l}^{3+}$ is surrounded by $6C{l}^{-}$ ions. So the coordination number will be 6.

In molten state, in exists as a dimer $\left(A{l}_{2}C{l}_6\right)$. The structure of crystalline $AlC{l}_3$ is given here.