In the diazotisation of aniline with sodium nitrite and hydrochloric acid, the excess of hydrochloric acid is used primarily to

Question

In the diazotisation of aniline with sodium nitrite and hydrochloric acid, the excess of hydrochloric acid is used primarily to (A) suppress the concentration of free aniline available for coupling (B) suppress the hydrolysis to phenol (C) ensure a stoichiometric amount of nitrous acid and HCl (D) neutralise the base liberated.

Tardigrade Admin · Accepted Answer

Mineral acid should be added in excess in diazotisation of aryl amines so, as to prevent the coupling of benzene diazonium chloride with excess of aryl amine.

Q. In the diazotisation of aniline with sodium nitrite and hydrochloric acid, the excess of hydrochloric acid is used primarily to

suppress the concentration of free aniline available for coupling

suppress the hydrolysis to phenol

ensure a stoichiometric amount of nitrous acid and $H Cl$

neutralise the base liberated.

Mineral acid should be added in excess in diazotisation of aryl amines so, as to prevent the coupling of benzene diazonium chloride with excess of aryl amine.