Answer the question on the basis of passage given below:

There are three kinds of amines which are primary, secondary and tertiary amines. These amines may have alkyl group or aryl group or both alkyl and aryl groups. These amines can be distinguished from one another by various chemical tests.

Which of the following amines when treated with chloroform and \(KOH\) give foul smelling substance. \(A\) is:

A. Primary amine

B. Secondary amine

C. Tertiary amine

D. Aniline

A and D

The correct answer is option 3. A and D.

When amines are treated with chloroform (\(CHCl_3\)) and potassium hydroxide (\(KOH\)), they undergo the Carbylamine reaction. In this reaction, the amine reacts with chloroform in the presence of a strong base like \(KOH\) to form an isocyanide compound (also known as a carbylamine), which often has a foul smell.

The Carbylamine reaction can be summarized as follows:

\(\text{RNH}_2 + 3\text{CHCl}_3 + 4\text{KOH} \rightarrow \text{RNC} + 3\text{KCl} + 3\text{H}_2\text{O} + 2\text{K}_2\text{CO}_3 \)

Now, let us analyze each option:

A. Primary amine: Primary amines have the general structure \(RNH_2\), where \(R\) represents an alkyl or aryl group. In the Carbylamine reaction, primary amines react with chloroform (\(CHCl_3\)) and potassium hydroxide (\(KOH\)) to form foul-smelling isocyanide compounds. This reaction is characterized by the replacement of the amino group (\(NH_2\)) with an isocyanide group (\(RNC\)). Primary amines have an available hydrogen atom on the nitrogen, which is necessary for this reaction to occur.

B. Secondary amine: Secondary amines do not give a positive carbylamine test because they lack the necessary hydrogen atom bonded directly to the nitrogen atom. In secondary amines, the nitrogen atom is bonded to two carbon atoms, not a hydrogen and a carbon like in primary amines. Therefore, secondary amines cannot undergo the necessary reaction to form isocyanides, and thus they do not produce the characteristic foul odor associated with the carbylamine test.

C. Tertiary amine: Tertiary amines have the general structure \(R_3N\), where \(R\) represents an alkyl or aryl group. Tertiary amines do not have any hydrogen atoms bonded directly to the nitrogen atom. Therefore, they cannot undergo the Carbylamine reaction because there are no hydrogen atoms available for substitution.

D. Aniline: Aniline is a primary aromatic amine with the structure \(C_6H_5NH_2\). It can also undergo the Carbylamine reaction because it has an available hydrogen atom on the amino group, similar to aliphatic primary amines.

Considering the Carbylamine reaction and the structures of the different types of amines, we can conclude that option 3 (A and D) is the correct choice.