Question

Which one of the following test can be used to distinguish between aldehyde and ketone?

• A. Fehling's solution
• B. Tollen's reagent
• C. Benedict's solution
• D. All of these

Answer 1

The correct option is D All of these

Fehling solution $\Rightarrow \text{Alkaline}CuS{O}_4+Na-K$ tartarate

Tollen's reagent $\Rightarrow N{H}_{4}OH+AgN{O}_3$

Bendict's solution:$\Rightarrow \text{Alkaline}CuS{O}_4+\text{Cirate ion}$

All these reagents are used to distinguish between aldehydes and ketones. Aliphatic aldehydes give both Tollens' and Fehlings' test. Aromatic aldehydes give only Tollens' test. Aliphatic ketone neither gives Tollens' nor Fehlings' test except $\alpha$-hydroxy ketone (terminal). Hence, the correct answer is option (d).