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Correct Answer: D
Correct Answer: D
Method / Topic: Organic Chemistry
The correct option matches the required rule and the given information.
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Correct Answer: D
Method / Topic: Organic Chemistry
Butanone matches C4H8O, contains a ketone carbonyl near 1715 cm−1, reacts with 2,4-DNP, and is Tollens-negative. Its proton NMR shows the expected 3 H triplet, 2 H quartet, and 3 H singlet for its ethyl and carbonyl-methyl proton sets. The other choices conflict with the carbonyl, NMR, or Tollens evidence. This conclusion follows from electron flow, functional-group behavior, and the stated experimental conditions. For MCAT organic chemistry, first mark the nucleophile, electrophile, leaving group, and any resonance-stabilized intermediate; then track bonds rather than memorizing a product name. Check stereochemistry, charge, and carbon count before choosing an
, and interpret evidence without overclaiming. Always reconcile the proposed structure with every observation in the
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PASSAGE 3 — IDENTIFYING AN UNKNOWN CARBONYL COMPOUND An unknown liquid has molecular formula C4H8O. Its IR spectrum contains a strong absorption near 1715 cm−1 but no broad O–H band. Its proton NMR spectrum shows three signals: a 3 H triplet, a 2 H quartet, and a 3 H singlet. The compound gives a positive 2,4-DNP test and a negative Tollens test. On reduction with sodium borohydride, it forms an alcohol. QUESTION 9: Which structure is most consistent with all the data?
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Correct Answer: D
Method / Topic: Organic Chemistry
The correct option matches the required rule and the given information.
Short Explanation
Detailed Explanation
Correct Answer: D
Method / Topic: Organic Chemistry
Butanone matches C4H8O, contains a ketone carbonyl near 1715 cm−1, reacts with 2,4-DNP, and is Tollens-negative. Its proton NMR shows the expected 3 H triplet, 2 H quartet, and 3 H singlet for its ethyl and carbonyl-methyl proton sets. The other choices conflict with the carbonyl, NMR, or Tollens evidence. This conclusion follows from electron flow, functional-group behavior, and the stated experimental conditions. For MCAT organic chemistry, first mark the nucleophile, electrophile, leaving group, and any resonance-stabilized intermediate; then track bonds rather than memorizing a product name. Check stereochemistry, charge, and carbon count before choosing an
, and interpret evidence without overclaiming. Always reconcile the proposed structure with every observation in the
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