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

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

Column I	Column II
(a) NH3	(iv) Monodentate ligand
(b) NO2	(iii) Ambidentate ligand
(c) en	(ii) Bidentate ligand
(d) EDTA	(i) Chelating ligand

Let us delve deeper into the properties of each ligand and why they match with their corresponding entries in Column II:

(a) NH₃(iv) Monodentate ligand: Ammonia is a Monodentate ligand. Ammonia \((NH_3)\) can donate one pair of electrons from its nitrogen atom to form one coordinate bond with a central metal ion. It does not form a ring structure.

(b) NO₂(iii) Ambidentate ligand: \(NO_2\) is an ambidentate ligand. The nitrite ion \((NO_2^-)\)can donate electrons either from the nitrogen atom (as nitro-N) or from one of the oxygen atoms (as nitro-O), but not simultaneously from both. It cannot form a ring structure.

(c) en(ii) Bidentate ligand: Ethylene diamine (en) bidentate ligand. Ethylenediamine (en) has two amine groups \((-NH_2)\) that can each donate a pair of electrons to form two coordinate bonds with a central metal ion. It typically forms a ring structure when coordinated.

(d) EDTA(i) Chelating ligand: EDTA is a chelating ligand. EDTA is a large organic molecule with four carboxylate groups \((-COO^-)\) and two amine groups \((-NH_2)\). It can donate multiple pairs of electrons to form multiple coordinate bonds with a central metal ion, forming a stable ring structure.

Therefore, the correct matching is: (a)-(iv), (b)-(iii), (c)-(ii), (d)-(i)

This pairing correctly identifies each ligand in Column I with its corresponding coordination type in Column II based on their chemical properties and coordination behaviors in coordination chemistry.