Formation of Azo Compound

An azo compound is formed when benzene diazonium chloride reacts with 2,4,6-trimethylphenol and phenol. The reaction involves the substitution of diazonium group (-N2+) with the hydroxyl group (-OH) of the phenol. The reaction is called diazotization.

Diazotization Reaction

Diazotization is a chemical reaction that involves the conversion of an aromatic primary amine to a diazonium salt by the action of nitrous acid. It is a two-step process that involves the formation of a diazonium intermediate, which then reacts with a nucleophile to form the final product.

Step 1: Diazotization of Aromatic Primary Amine

In the first step of diazotization, an aromatic primary amine is treated with nitrous acid (HNO2) to form a diazonium salt. The reaction can be represented as:

R-NH2 + HNO2 → R-N2+Cl- + H2O

where R represents the aromatic group.

Step 2: Reaction with Nucleophile

In the second step, the diazonium salt reacts with a nucleophile (such as phenol or 2,4,6-trimethylphenol) to form the final product, which is an azo compound. The reaction can be represented as:

R-N2+Cl- + Ar-OH → R-N=N-Ar + HCl + H2O

where Ar represents the aromatic ring.

Formation of Azo Compound from Benzene Diazonium Chloride

When benzene diazonium chloride reacts with 2,4,6-trimethylphenol or phenol, an azo compound is formed. The reaction can be represented as:

C6H5-N2+Cl- + Ar-OH → C6H5-N=N-Ar + HCl + H2O

where Ar represents the aromatic ring of 2,4,6-trimethylphenol or phenol.

Therefore, option B (Both A and B) is the correct answer as both 2,4,6-trimethylphenol and phenol can react with benzene diazonium chloride to form azo compounds.