IB Chemistry R3.4 Electron-pair Sharing Reactions Questionbank

(c) Outline the full mechanism for the reaction you chose, using curly arrows.

In the reaction between aluminium trichloride ($\text{AlCl}_3$) and a chloride ion ($\text{Cl}^-$) to form the tetrachloroaluminate ion ($[\text{AlCl}_4]^-$), which statement correctly describes the role of the $\text{AlCl}_3$ molecule?

The halogen atom

The hydrogen atom

The carbon bonded to the halogen

The carbon bonded to hydrogen

(a) Compare the mechanisms of $\text{S}_{\text{N}}1$ and $\text{S}_{\text{N}}2$ reactions with reference to the number of steps involved.

(b) For the reaction of $(\text{CH}_3)_3\text{CBr}$ with $\text{OH}^-$, identify the likely mechanism and explain your choice.

The first step in a reaction mechanism is shown.

Which statements are correct?

I. The leaving group is the bromide ion.

II. The carbocation has a trigonal planar geometry.

III. The $\text{C-Br}$ bond undergoes homolytic fission.

The iron(III) ion forms the complex ion $[\mathrm{Fe(H_2O)_6}]^{3+}$, shown.

Which statements are correct?

I. The charge on the complex ion is $3+$

II. The water molecules are acting as Lewis bases

III. The complex ion has coordination number 6