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A-LevelChemistryCarboxylic acids and derivativesOct/Nov 2025Paper 1 Q331 Mark

HOCH2CHO is heated under reflux with an excess of acidified K2Cr2O7 until there is no further reaction. What is the final product of this reaction?

AHOOCCHO
BHOCH2COOH
CHOOCCOOH
DHOOCCH2COOH

✓ Correct Answer

The correct answer is C: HOOCCOOH

📋 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 Carboxylic acids and derivatives in A-Level Chemistry (syllabus code 9701). It is worth 1 mark.

Source

This question appeared in the Cambridge A-Level Chemistry Oct/Nov 2025 examination, Paper 1 Variant 2.

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