Question:
Which of the following compounds gives a positive Tollen's test but negative Fehling's test?
Which of the following compounds gives a positive Tollen's test but negative Fehling's test?
Show Hint
Fehling's test is the standard way to distinguish Aliphatic vs. Aromatic Aldehydes.
Updated On: Apr 17, 2026
- Acetaldehyde
- Benzaldehyde
- Acetophenone
- Acetone
Show Solution
Verified By Collegedunia
The Correct Option is B
Solution and Explanation
Step 1: Concept
Tollen's reagent oxidizes both aliphatic and aromatic aldehydes. Fehling's solution oxidizes aliphatic aldehydes but generally fails to oxidize aromatic aldehydes.
Step 2: Analysis
Step 3: Conclusion
Benzaldehyde fits the criteria.
Final Answer:(B)
Tollen's reagent oxidizes both aliphatic and aromatic aldehydes. Fehling's solution oxidizes aliphatic aldehydes but generally fails to oxidize aromatic aldehydes.
Step 2: Analysis
- Acetaldehyde (Aliphatic): Positive for both.
- Benzaldehyde (Aromatic): Positive Tollen's, Negative Fehling's.
- Acetophenone/Acetone (Ketones): Negative for both.
Step 3: Conclusion
Benzaldehyde fits the criteria.
Final Answer:(B)
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