Question

Name a compound that gives a positive iodoform test.

Answer 1

Explanation for correct answer:

• Compounds having one methyl group at carbonyl carbon gives positive test of Iodoform test.
• These compounds are Aldehyde and Ketones.
• The compound reacts with Iodine in the presence of sodium hydroxide to form a yellow color precipitate which is called Iodoform.

• This test is carried out to check the presence of carbonyl compounds in a given unknown substance having the structure $\mathrm{R}-\mathrm{CO}-{\mathrm{CH}}_3$ or alcohols with the structure $\mathrm{R}-\mathrm{CH}\left(\mathrm{OH}\right)-{\mathrm{CH}}_3$.
• For example, a compound having an alcohol group reacts with Iodine to form an Iodoform(triidomethane).

Therefore, Acetaldehyde is a compound that gives positive Iodoform test.