Moderate

An organic compound C2H6O neither gives a precipitate with semicarbazide nor reacts with sodium. It should be:

Correct answer: D. Dimethyl ether

  • A. Propionaldehyde
  • B. Acetone
  • C. Propan-2-ol
  • D. Dimethyl ether

Explanation

The correct answer is Dimethyl ether. Ethers do not form precipitates with semicarbazide because this reaction is specific to carbonyl compounds like aldehydes and ketones, which diethyl ether is not. Additionally, ethers are not reactive with sodium, which rules out the possibility of the compound being an alcohol. The other options are incorrect because both aldehydes and ketones would react with semicarbazide to form a precipitate. Alcohols would react with sodium, producing hydrogen gas.

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About Aldehydes and Ketones

Aldehydes and ketones contain the polar carbonyl group, but aldehydes are generally more readily oxidised and more reactive than ketones. Coverage includes preparation by oxidation or reduction routes, nucleophilic addition of reagents such as hydrogen cyanide and bisulfite, and tests that distinguish aldehydes from ketones.

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