Question

Following compounds are given: (1) CH₃CH₂OH (2) CH₃COCH₃ (3) CH₃-CHOH-CH₃ (4) CH₃OH Which of the above compound(s), on being warmed with iodine solution and NaOH, will give iodoform?

• A. (1) and (2)
• B. (1), (3) and (4)
• C. only (2)
• D. (1), (2) and (3)

Hint:

All methyl ketones and secondary alcohols with CH₃–CHOH– give iodoform test.

Answer 1

The Correct Option is D

Step 1: Iodoform test is given by compounds containing: CH₃CO– or CH₃–CHOH–
Step 2: (1) Ethanol → oxidised to acetaldehyde → gives iodoform (2) Acetone has CH₃CO– group (3) Isopropyl alcohol has CH₃–CHOH– group (4) Methanol does not satisfy the condition