Aldehydes And Ketones

Step 1: Concept
The Iodoform test requires the presence of a methyl keto group ( ) or a secondary alcohol that can be oxidized to it ( ).
Step 2: Analysis

• Ethanol ( ) and Ethanal ( ) both possess the required structure.
• Propan-2-ol ( ) is a alcohol with a terminal methyl, so it gives a positive test.
• Butan-1-ol ( ) is a alcohol with no methyl attached to the carbinol carbon.

Step 3: Conclusion
Hence, Butan-1-ol does not give the iodoform test.
Final Answer:(D)

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

• 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)