Which one of the following will not form a yellow precipitate on heating with an alkaline solution of iodine?

Which one of the following will not form a yellow precipitate on heating with an alkaline solution of iodine?
  1. $\mathrm{CH}_3 \mathrm{CH}(\mathrm{OH}) \mathrm{CH}_3$
  2. $\mathrm{CH}_3 \mathrm{CH}_2 \mathrm{CH}(\mathrm{OH}) \mathrm{CH}_3$
  3. $\mathrm{CH}_3 \mathrm{OH}$
  4. $\mathrm{CH}_3 \mathrm{CH}_2 \mathrm{OH}$

Solution

The carbonyl compounds which contains the $\mathrm{CH}_3 \mathrm{CO}-$ or the $\mathrm{CH}_3 \mathrm{C}(\mathrm{H})$ $(\mathrm{OH})$-compounds undergo the iodoform reaction. Benzyl alcohol, Methanol, Diethyl ketone, acetic acid do not give iodoform test. Caution Compounds that give positive Iodoform Test are Acetaldehyde, Methyl Ketone, Ethanol, Secondary Alcohols that contain methyl groups in alpha position.

Asked in: NEET 2004

Practice more Alcohols Phenols and Ethers questions on Aicharya