Aluminium chloride speeds up certain reactions by producing carbocations from chloroalkanes, as illustrated. $\text{RCl} + \text{AlCl}_3 \rightarrow \text{R}^+ + \text{AlCl}_4^-$ Which property allows this reaction to occur?
- A$\text{AlCl}_3$ exists as the dimer $\text{Al}_2\text{Cl}_6$ in the vapour.
- B$\text{AlCl}_3$ is a covalent molecule.
- CThe aluminium atom in $\text{AlCl}_3$ has an incomplete octet of electrons.
- DThe chlorine atom in $\text{RCl}$ has a vacant $p$ orbital.