Which one of the following does not give iodoform test?
Correct answer: B. 3-hexanone
- A. Acetaldehyde
- B. 3-hexanone
- C. Butanone
- D. Acetone
Explanation
3-hexanone does not give the iodoform test. The iodoform test is a chemical test used to detect the presence of methyl ketones. Methyl ketones are ketones that have a methyl group (CH3) bonded to the carbonyl group (C=O). The iodoform test is carried out by reacting the compound with iodine (I2) and sodium hydroxide (NaOH). If the compound is a methyl ketone, a yellow precipitate of iodoform (CHI3) will form. 3-hexanone is not a methyl ketone because it does not have a methyl group bonded to the carbonyl group. Therefore, it will not give the iodoform test.
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About Reactivity of Aldehydes and Ketones
The polar carbonyl group makes aldehydes and ketones undergo nucleophilic addition, reduction and condensation reactions. Aldehydes are generally more reactive and oxidise readily to carboxylic acids, whereas ketones resist mild oxidation; reactions with hydrogen cyanide, sodium bisulfite and 2,4-DNP help identify their behaviour.
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