(i) When aromatic amine reacts with nitrous acid (which is generated in situ from NaNO₂) and a mineral acid like phosphoric acid, it produces nitrous oxide.

(ii) When aliphatic primary amines react with nitrous acid (produced in situ from NaNO2) and a mineral acid such as HCl, unstable aliphatic diazonium salts develop, which later create alcohol and HCl, as well as N₂ gas.

At 273–278 K, (HCl) forms stable aromatic diazonium salts, such as NaCl and H₂O.