Iodoform test is not given by:A) 2-PentanoneB) EthanolC) EthanalD) 3-pentanone

The correct answer is B) Ethanol.

The iodoform test is a chemical test used to detect the presence of compounds that have the CH3CO group (acetyl group) in their structure. In this test, the compound is treated with iodine and sodium hydroxide (NaOH) in the presence of water or ethanol as a solvent.

During the iodoform test, a yellow precipitate of iodoform (CHI3) is formed if the compound being tested contains the CH3CO group. The reaction proceeds through a series of steps involving the oxidation of the CH3CO group and subsequent substitution with iodine.

2-Pentanone (choice A), Ethanal (choice C), and 3-pentanone (choice D) all have the CH3CO group in their structure and, therefore, give positive results in the iodoform test. However, ethanol (choice B) does not contain the CH3CO group and does not give a positive iodoform test.