Which of the following will not give iodoform test?

The correct answer is option 2. benzyl alcohol.

The iodoform test is a chemical test used to detect the presence of methyl ketone or acetaldehyde. The test is based on the oxidation of the compound to form a triiodomethane (iodoform) precipitate.

The compounds that will give a positive iodoform test are those that contain a methyl ketone group \((CH_3CO^-)\) or acetaldehyde \((CH_3CHO)\). Ethanol \((CH_3CH_2OH)\) can also give a positive iodoform test, because it can be oxidized to acetaldehyde.

Benzyl alcohol \((C_6H_5CH_2OH)\) does not contain a methyl ketone group, so it will not give a positive iodoform test.

Here is a table of the compounds and their expected results with the iodoform test:

Compound	Expected Result
Ethanal	Positive
Ethanol	Positive
Isopropyl alcohol	Positive
Benzyl alcohol	Negative