Identify compounds A,B and C in the following sequence of reactions.
`C_6H_5NO_2overset(Fe"/"HCl)(to)A underset(273K)overset(HNO_2)(to)B overset(C_6H_5OH)(to)C`

Explanation

`{:(C_6H_5NO_2 underset(6(H))overset(Fe"/"HCl)(to)C_6H_5NH_2),(" "" (A) Aniline "):}`
`{:(C_6H_5NH_2+HNO_2 underset(273 K)overset(HCl)(to)C_6H_5N=N-Cl),("(A) Aniline"" Nitrous Acid " " (B) Benzene Diazonium "):}`
The reaction is known as chloride diazotisation.

The reaction is known as coupling reaction.