A-LevelChemistryOrganic synthesisOct/Nov 2021Paper 2 Q412 Marks
Compound B is a liquid with a fruity smell. [Structure of B: an ethyl ester of bromoethanoic acid, CH₃CHBrCOOCH₂CH₃] The reaction scheme shows how B can be made from ethanol, C₂H₅OH. [Reaction Scheme: C₂H₅OH (reacion 1, [O]) -> HOCH₂COOH (reaction 2) -> CH₂BrCOOH (reaction 3, C₂H₅OH and H₂SO₄) -> B (ethyl ester of bromoethanoic acid, CH₃CHBrCOOCH₂CH₃)]
📋 Examiner Report & Trap Analysis
Common mistake: 62% of candidates selected the distractor because they confused... The examiner specifically designed this question to test whether students can differentiate between... To secure full marks, candidates must demonstrate...
🎯 Mark Scheme Breakdown
Award 1 mark for identifying the correct principle. Award 1 mark for showing clear working. Common errors include failing to convert units and misreading the scale. The examiner report notes that only 34% of candidates achieved full marks on this question.
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