Question

Which of the following on reaction with NaOI will give yellow precipitates?
(A) Phenylethanone
(B) Sec-Butyl alcohol
(C) Phenylethanal
(D) Methyl n-propylketone
Choose the correct answer from the options given below:

• A. A, B, and D only
• B. A, B, and C only
• C. A, B, C, and D
• D. B, C, and D only

Answer 1

The Correct Option is B

The haloform reaction predicts yellow precipitates with NaOI, specifically with methyl ketones, alcohols with adjacent methyl groups, and certain aldehydes.

A. Phenylethanone (Acetophenone): Possesses a methyl group adjacent to a carbonyl, enabling the haloform reaction and the formation of iodoform (yellow precipitate).

B. Sec-Butyl alcohol: Oxidizes to a methyl ketone with an adjacent methyl group, which undergoes the haloform reaction to produce iodoform.

C. Phenylethanal: An aldehyde with an adjacent methyl group, capable of participating in the haloform reaction and forming yellow precipitates.

D. Methyl n-propylketone: Lacks the required methyl group adjacent to the carbonyl for the haloform reaction, thus will not yield yellow precipitates.

Compounds A, B, and C will produce yellow precipitates with NaOI. The correct answer is: A, B, and C only