Question

Which of the following will not give iodoform test?

• A. Isopropyl alcohol
• B. Ethanol
• C. Ethanal
• D. Benzyl alcohol

Hint:

Mnemonic: Only compounds with \(-COCH_3\) or \(-CHOHCH_3\) groups respond to the iodoform test.

Answer 1

The Correct Option is D

Step 1: Recall iodoform test.
The iodoform test is given by compounds having the group \(-COCH_3\) or \(-CHOHCH_3\). Examples: ethanol, ethanal, and isopropyl alcohol.
Step 2: Analyze options.
(A) Isopropyl alcohol: Has \(-CHOHCH_3\), gives test.
(B) Ethanol: On oxidation gives acetaldehyde (\(-COCH_3\)), gives test.
(C) Ethanal: Directly has \(-COCH_3\), gives test.
(D) Benzyl alcohol: Does not have the required group, so does not give iodoform test.
Step 3: Conclusion.
Thus, the correct answer is (D) Benzyl alcohol.