Match List-I with List-II
| List-I | List-II |
| (Organic Compound) | (Characteristics) |
| (A) Benzene sulphonyl chloride | (I) Zwitter Ion |
| (B) Sulphanilic Acid | (II) Hinsberg Reagent |
| (C) p-Hydroxyazobenzene | (III) Orange dye |
| (D) ArN2+Cl− +CuCN / KCN | (IV) Sandmeyer reaction |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → (A) - (II), (B) - (I), (C) - (III), (D) - (IV)
All four items are aromatic compounds or reactions of amines and diazonium salts. Each is recognised by its use, its structure or the name of the reaction:
(A) Benzene sulphonyl chloride — This matches (II) Hinsberg Reagent. \( \ce{C6H5SO2Cl} \) distinguishes the three classes of amines: a primary amine gives a sulphonamide soluble in alkali, a secondary amine gives a sulphonamide insoluble in alkali, and a tertiary amine does not react:
\( \displaystyle \ce{C6H5SO2Cl + H-NH-R -> C6H5SO2NHR + HCl} \)
(B) Sulphanilic Acid — This matches (I) Zwitter Ion. In 4-aminobenzenesulphonic acid, the acidic –\( \ce{SO3H} \) group transfers its proton to the basic –\( \ce{NH2} \) group of the same molecule, giving a dipolar ion:
\( \displaystyle \ce{H2N-C6H4-SO3H -> H3N^+-C6H4-SO3^-} \)
(C) p-Hydroxyazobenzene — This matches (III) Orange dye. It is formed by coupling benzenediazonium chloride with phenol in mildly alkaline medium.
\( \displaystyle \ce{C6H5N2^+Cl^- + C6H5OH} \xrightarrow{\ce{OH^-}} \ce{C6H5-N=N-C6H4-OH + Cl^- + H2O} \)
(D) \( \ce{ArN2^{+}Cl^{-}} \) +CuCN / KCN — This matches (IV) Sandmeyer reaction. A copper(I) salt replaces the diazonium group by a nucleophile, here –CN.
\( \displaystyle \ce{ArN2^+Cl^-} \xrightarrow{\ce{CuCN}/\ce{KCN}} \ce{ArCN + N2} \)
Shortcut: The pair (C)–(III) appears only in Option (3).