PYQ NEET- Aldehydes Ketones Carboxylic Acids

• 2019: A compound with molecular formula C6H12O2 gives iodoform test and forms 2,4-DNP derivative. On reduction with LiAlH4, it gives a sweet smelling compound. The compound is:

(A) Acetone (B) Propan-2-one (C) Propanal (D) Butanal

Answer: (A) Acetone Explanation:

The molecular formula C6H12O2 matches the formula for ethyl acetate (CH3COOCH2CH3). The compound gives a positive iodoform test because it contains a methyl ketone group (CH3CO-). The compound forms a 2,4-DNP derivative because it contains a ketone group (RCO-). The compound is reduced to a sweet smelling compound, 1-propanol (CH3CH2CH2OH), with LiAlH4.

• 2018: Which of the following compounds does not undergo aldol condensation?

(A) Propanal (B) Benzaldehyde (C) Acetaldehyde (D) Trichloroacetaldehyde

Answer: (D) Trichloroacetic acid