Almond essence is used to flavour foods. A student tested a sample of almond essence using 2.4-dinitrophenylhydrazine reagent and obtained coloured crystals which had a sharp melting point. Which class of compound gives this positive result?
Correct answer: B. Aldehydes
- A. Alcohols
- B. Aldehydes
- C. Amines
- D. Carboxylic acids
Explanation
The correct option for the class of compound that gives a positive result when tested with 2,4-dinitrophenylhydrazine reagent and forms colored crystals with a sharp melting point is B) Aldehydes. The positive test indicates the presence of an aldehyde functional group in the compound being tested.
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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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682 free Aldehydes and Ketones MCQs from Chemistry, each with the correct answer and an explanation. Unlimited attempts, no account needed.
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