Question

A student is given one compound among the following compounds that gives positive test with Tollen's reagent. The compound is:

• A. B
• B. A
• C. C
• D. D

Hint:

Hemiacetals give positive Tollen’s test, while acetals do not.

Answer 1

The Correct Option is C

Step 1: Understanding Tollen’s reagent test.
Tollen’s reagent gives a positive test with aldehydes and compounds that can form aldehydes under reaction conditions.
Step 2: Analysing the given compounds.
Compound A and B: These are acetals/ethers. Acetals do not undergo oxidation by Tollen’s reagent and hence do not give a positive test.
Compound D: This compound is an alcohol without the ability to form an aldehyde under Tollen’s test conditions. Hence, it does not give a positive test.
Compound C: This compound is a hemiacetal. Hemiacetals are in equilibrium with aldehydes in aqueous medium. The aldehyde formed reacts with Tollen’s reagent to produce silver mirror.
Step 3: Conclusion.
Only compound C gives a positive Tollen’s test.