Which reaction involves addition-elimination? A (C₃H₇)Br + KOH → C₃H₅CH₂ + KBr + H₂O B CH₃COCl + C₂H₅OH → CH₃COOCH₂CH₃ + HCl C CH₂=CH₂ + Cl₂ → CH₃CHClCH₂Cl D CH₃CH₂CHBr + NaOH → CH₃CH₂CH₂OH + NaBr - AQA - A-Level Chemistry - Question 27 - 2020 - Paper 3

The reaction involving addition-elimination is option B. In this reaction, the acyl chloride (CH₃COCl) reacts with ethanol (C₂H₅OH) to form an ester (CH₃COOCH₂CH₃) and hydrochloric acid (HCl). The addition of the alcohol to the acyl chloride results in the formation of a tetrahedral intermediate, followed by elimination of HCl, characteristic of addition-elimination mechanisms.