Which of the following reactions is NOT shown by ketones?
Correct answer: B. Reaction with Fehling solution
- A. Reaction with HCN
- B. Reaction with Fehling solution
- C. Reaction with NaHSO3
- D. Reaction with 2,4-dinitrophenyl-hydrazine
Explanation
Fehling's solution is a mixture of Rochelle salt (blue color) and copper sulphate (chso4). It is an oxidizing agent which is used to diffentiate between aldehydes and ketones. Ketones generally do not react with Fehling's solution. A red colored precipetate is formed when Fehling's solution is reacted with aldehyde.Reaction with HCN:Ketones when added with HCN give hydroxynitriles. HCN will be added with the carbon-oxygen double bond to produce hydroxynitriles.Rxn with NaHso3:Ketones generally get added with NaHSO3 by the process of nucleophilic addition.Rxn with 2,4 dinitrophenol hydrazine:Aldehydes and ketones on reaction with this generally form orange/yellow precipitates.
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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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