A-LevelChemistryOrganic synthesisMay/June 2020Paper 1 Q401 Mark

A reaction mechanism is shown. [Diagram showing a reaction mechanism for the addition of HBr to an alkene followed by substitution by OH-.] Which statements about this reaction are correct? 1 Heterolytic bond fission occurs. 2 It is a substitution reaction. 3 OH¯ behaves as an electrophile.

Q: What is the correct answer to this A-Level Chemistry question?

The correct answer is B: 1 and 2 only are correct.

Q: What topic does this question test?

This question tests Organic synthesis in A-Level Chemistry (syllabus code 9701). It is worth 1 mark.

A1, 2 and 3 are correct

B1 and 2 only are correct

C2 and 3 only are correct

D1 only is correct

✓ Correct Answer

The correct answer is B: 1 and 2 only are correct

📋 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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About This A-Level Chemistry Question

Topic

This multiple-choice question tests Organic synthesis in A-Level Chemistry (syllabus code 9701). It is worth 1 mark.

Source

This question appeared in the Cambridge A-Level Chemistry May/June 2020 examination, Paper 1 Variant 2.

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