A Levels Chemistry (9701)•9701/11/O/N/19

Explanation
Empirical formula and oxidation product identification Steps:
- From percentages in 100 g Y: C = 54.54 g (4.545 mol), H = 9.10 g (9.10 mol), O = 36.36 g (2.273 mol).
- Ratio by dividing by smallest (2.273): C:H:O = 2:4:1, so empirical formula C₂H₄O (Mᵣ 44).
- Molecular formula is 2 × empirical (88/44 = 2), giving C₄H₈O₂.
- C₄H₈O₂ matches butanoic acid (CH₃CH₂CH₂COOH), oxidation product of primary alcohol butan-1-ol.
Why D is correct:
- Butan-1-ol (CH₃CH₂CH₂CH₂OH) oxidizes to butanoic acid (C₄H₈O₂, Mᵣ 88) via loss of 2 H and gain of O, matching exact composition.
Why the others are wrong:
- A: Propan-2-ol oxidizes to acetone (C₃H₆O, Mᵣ 58, 62.1% C), wrong formula and percentages.
- B: Propan-1-ol oxidizes to propanoic acid (C₃H₆O₂, Mᵣ 74, 48.6% C), wrong carbon count and percentages.
- C: Butan-2-ol oxidizes to butan-2-one (C₄H₈O, Mᵣ 72, 66.7% C), lacks second oxygen atom.
Final answer: D
Topic: Hydroxy compounds
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