Given the structure of A, B, and C in the following reactions:
(i) C6H5N+2Cl⁻ + CuCN → A
A + H₂O/H⁺ → B
B + NH₃ → Δ + C
(ii) C6H5NO₂ + Sn + HCl → A
A + NaNO₂ + HCl → 273K
B + H₂O.H⁺ → Δ + C

The reactions given are:
(i) C₆H₅N₂⁺Cl⁻ + CuCN → A
A + H₂O/H⁺ → B
B + NH₃ → Δ + C
(ii) C₆H₅NO₂ + Sn + HCl → A
A + NaNO₂ + HCl → 273K
B + H₂O.H⁺ → Δ + C

Reaction (i):
This reaction involves the Sandmeyer reaction. C₆H₅N₂⁺Cl⁻ (benzenediazonium chloride) reacts with CuCN to form benzonitrile (A).

C₆H₅N₂⁺Cl⁻ + CuCN → C₆H₅CN + N₂ + CuCl
(A: Benzonitrile)

Hydrolysis of benzonitrile (A) with H₂O/H⁺ produces benzoic acid (B).

C₆H₅CN + H₂O/H⁺ → C₆H₅COOH + NH₄⁺
(B: Benzoic acid)

Heating benzoic acid (B) with ammonia (NH₃) leads to the formation of benzamide (C) and water.

C₆H₅COOH + NH₃ → C₆H₅CONH₂ + H₂O
(C: Benzamide)

Reaction (ii):
This reaction sequence starts with the reduction of nitrobenzene (C₆H₅NO₂) using tin (Sn) and hydrochloric acid (HCl) to produce aniline (A).

C₆H₅NO₂ + 6[H] → C₆H₅NH₂ + 2H₂O
(A: Aniline)

Diazotization of aniline (A) with NaNO₂ and HCl at 273 K yields benzenediazonium chloride (B).

C₆H₅NH₂ + NaNO₂ + 2HCl → C₆H₅N₂⁺Cl⁻ + NaCl + 2H₂O
(B: Benzenediazonium chloride)

This benzenediazonium chloride (B), on warming with water and acid (H₂O.H⁺), undergoes hydrolysis to form phenol. The phenol is then heated, leading to the formation of various products. It's not clear what C represents after the reaction of B with H2O/H+. It could undergo further reaction. However, the initial product will be phenol.

C₆H₅N₂⁺Cl⁻ + H₂O → C₆H₅OH + N₂ + HCl
(In this reaction, B reacts to form phenol before forming any other product in this pathway)