Match the entries of column I with appropriate entries of column II a…

The correct answer is option 4. (i)-(b), (ii)-(a), (iii)-(d), (iv)-(c).

Column I	Column II
(i) Benzenesulphonyl chloride	(b) Hinsberg reagent
(ii) Sulphanilic acid	(a) Zwitter ion
(iii) Alkyldiazonium salts	(d) Conversion to alcohols
(iv) Aryldiazonium salts	(c) Dyes

Let us delve into the explanations for each pair in Column I matched with Column II:

(i) Benzenesulphonyl chloride → (b) Hinsberg reagent

Benzenesulphonyl chloride is commonly known as the Hinsberg reagent in organic chemistry. It is used as a reagent to distinguish between primary, secondary, and tertiary amines through their reaction products:

Primary amines react with benzenesulphonyl chloride to form N-alkylbenzenesulfonamides, which are soluble in alkali but insoluble in acid.

Secondary amines react to form N,N-dialkylbenzenesulfonamides, which are soluble in both alkali and acid.

Tertiary amines do not react with benzenesulphonyl chloride under normal conditions.

(ii) Sulphanilic acid → (a) Zwitter ion

Sulphanilic acid is an aromatic sulfonic acid. In its crystalline form, it exists as a zwitterion, which is a molecule with both positive and negative charges:

In the case of sulphanilic acid, the sulfonic acid group \((-SO_3H)\) is acidic and can lose a proton \((H^+)\) to become negatively charged (anion). The amino group \((-NH_2)\) can gain a proton \((H^+)\) to become positively charged (cation). Therefore, in its crystalline form, sulphanilic acid can exist as a zwitterion due to the balance between these charges.

(iii) Alkyldiazonium salts → (d) Conversion to alcohols

Alkyldiazonium salts can decompose under certain conditions to liberate nitrogen gas \((N_2)\) and form alcohols:

Alkyldiazonium salts have the general structure \(R-N_2^+X^-\) (where \(R\) is an alkyl group). When treated with water or under conditions where the diazonium group \((N_2^+)\) decomposes, the alkyl group \((R)\) can be converted into an alcohol \((ROH)\).

(iv) Aryldiazonium salts → (c) Dyes

Aryldiazonium salts are versatile intermediates in organic synthesis, particularly in the formation of azo dyes:

Aryldiazonium salts have the general structure Ar-N2+X- (where Ar is an aryl group). They undergo coupling reactions with aromatic compounds or phenols to form azo dyes (compounds containing the functional group \(-N=N-\)).