A-LevelChemistryHydroxy compoundsFeb/Mar 2023Paper 1 Q351 Mark
Two isomeric alcohols, W and X, have molecular formula C4H9OH. W is oxidised to carbonyl compound Y which gives a red precipitate with Fehling's solution. X is oxidised to carbonyl compound Z which does not give a red precipitate with Fehling's solution. Which of W and X gives a yellow precipitate with alkaline I2(aq)?
Ainsufficient data is given to answer this question
BW only
CX only
Dneither W nor X
✓ Correct Answer
The correct answer is C: X only
📋 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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