Explanation

Iodoform test is given by compounds containing either a methyl ketone group (–COCH₃) or those alcohols which can be oxidized to methyl ketones.

Let us analyze each pair one by one.

A. Methanol and Ethanol
Ethanol on oxidation forms acetaldehyde which contains the –COCH₃ group and hence gives positive iodoform test. Methanol does not form a methyl ketone on oxidation and gives negative test.

So, Methanol and Ethanol can be differentiated. ✔

B. CH₃COOH and CH₃CH₂COOH
Both are carboxylic acids and do not contain methyl ketone group. Hence, both give negative iodoform test.

So, they cannot be differentiated. ✘

C. Cyclohexene and Cyclohexanone
Cyclohexanone does not contain –COCH₃ group. Cyclohexene is an alkene. Both give negative iodoform test.

So, they cannot be differentiated. ✘

D. Diethyl ether and Pentan-3-one
Pentan-3-one does not have –COCH₃ group. Diethyl ether also does not give iodoform test.

So, they cannot be differentiated. ✘

E. Anisole and Acetone
Acetone is a methyl ketone and gives positive iodoform test. Anisole does not give iodoform test.

So, they can be differentiated. ✔

Hence, the correct pairs are A and E only.

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