Consider the following statements about diazonium salts.(A) The salt…

The correct answer is Option (1) → (A), (C) and (D) only

Diazonium salts have the general formula ArN₂⁺X⁻. The –N₂⁺ group is the diazonium group. Aryl diazonium salts are made from primary aromatic amines, and even they keep only for a short time in the cold.

(A) The salt C₆H₅N₂⁺HSO₄⁻ is named benzenediazonium hydrogensulphate. — True. The name is the parent hydrocarbon + diazonium, followed by the name of the anion.

(B) The conversion of secondary aromatic amines into diazonium salts is known as diazotisation. — False. Diazotisation is the conversion of primary aromatic amines (Ar–NH₂) into diazonium salts.

(C) Primary aliphatic amines form highly unstable alkyldiazonium salts. — True. They break down at once, giving off nitrogen gas and an alcohol.

(D) Benzenediazonium chloride is not generally stored and is used immediately after its preparation. — True. This is because of its instability; it is made by diazotisation and used at once:

    \( \displaystyle \ce{C6H5NH2 + NaNO2 + 2HCl} \xrightarrow{\text{273–278 K}} \ce{C6H5N2^+Cl^- + NaCl + 2H2O} \)

NCERT (2026-27 edition):
II. Diazonium Salts – “…For example, C₆H₅N₂⁺Cl^– is named as benzenediazonium chloride and C₆H₅N₂⁺HSO₄^– is known as benzenediazonium hydrogensulphate.”

“Primary aliphatic amines form highly unstable alkyldiazonium salts (refer to Section 9.6).”

9.7 Method of Preparation of Diazonium Salts – “…The conversion of primary aromatic amines into diazonium salts is known as diazotisation. Due to its instability, the diazonium salt is not generally stored and is used immediately after its preparation.”