Electron-Pair Sharing Reactions · Paper 1 — Free Chemistry SL Practice Questions

In the reaction $\text{NH}_3 + \text{BF}_3 \rightarrow \text{H}_3\text{N} \rightarrow \text{BF}_3$, a dative covalent bond is formed. Which statement correctly describes the role of $\text{BF}_3$ in this reaction?

In the reaction $\text{AlCl}_3 + \text{Cl}^- \rightarrow \text{AlCl}_4^-$, which row correctly identifies the Lewis acid and the Lewis base?

In the reaction $\text{SO}_3 + \text{H}_2\text{O} \rightarrow \text{H}_2\text{SO}_4$, a dative covalent bond forms when a lone pair from water is donated to sulfur. Which species acts as the Lewis acid in this step?

In the first step of lidocaine synthesis, the nitrogen atom of 2,6-dimethylaniline donates its lone pair to the electrophilic carbonyl carbon of chloroacetyl chloride, forming a new C–N bond. Which row correctly identifies the Lewis acid and the Lewis base in this interaction?