Question

Iodoform test can differentiate :

• A. Anisole and Acetone
• B. Acetic acid and Aniline
• C. Ethanol and Acetone
• D. Methanol and benzoic acid

Hint:

The Iodoform test is specific for compounds containing either $R-\text{CO}-\text{CH}_3$ (methyl ketone) or $R-\text{CH}(\text{OH})-\text{CH}_3$ (methyl carbinol). $\text{CH}_3\text{OH}$ and $\text{CH}_3\text{CHO}$ are special cases that also test positive.

Answer 1

The Correct Option is A

Step 1: Iodoform test is a qualitative test used to identify compounds containing either: \[ R-CO-CH_3 \quad \text{(methyl ketone)} \] or \[ R-CH(OH)-CH_3 \quad \text{(methyl carbinol)} \] Step 2: Anisole ($Ph-O-CH_3$) is an ether. It does not contain either $COCH_3$ or $CH(OH)CH_3$ group.
Hence, anisole gives negative iodoform test. Step 3: Acetone ($CH_3-CO-CH_3$) is a methyl ketone.
On treatment with $I_2/NaOH$, it gives yellow precipitate of iodoform ($CHI_3$). Step 4: Since anisole does not respond and acetone responds positively, they can be clearly differentiated. Hence, correct answer is (1) Anisole and Acetone.