Match the LIST-I with LIST-II.
| LIST-I | LIST-II | ||
| A. | Crystal Field Splitting | I. | In coordination compounds metals show two types of linkages (valencies)-primary and secondary |
| B. | Werner Theory | II. | Metal atom or ion use its orbitals for hybridisation to yield a set of equivalent orbitals of definite geometry |
| C. | Valence Bond Theory | III. | Degeneracy of the d-orbitals removed due to ligand -metal interactions |
| D. | Crystal Field Theory | IV. | Electrostatic model which considers the metal-ligand bond as ionic |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → A - III, B - I, C - II, D - IV
Three ideas explain bonding in coordination compounds: Werner’s theory, valence bond theory (VBT) and crystal field theory (CFT). Each item in List-I is matched with its key idea.
A. Crystal Field Splitting — This matches III. Degeneracy of the d-orbitals removed due to ligand -metal interactions. In a free metal ion the five d orbitals have the same energy (they are degenerate). When ligands approach, their negative charges repel the d electrons unequally, so the orbitals split into sets of different energy, such as t2g and eg in an octahedral field.
B. Werner Theory — This matches I. In coordination compounds metals show two types of linkages (valencies)-primary and secondary. The primary valency is ionisable and equals the oxidation state; the secondary valency is non-ionisable and equals the coordination number.
C. Valence Bond Theory — This matches II. Metal atom or ion use its orbitals for hybridisation to yield a set of equivalent orbitals of definite geometry. The metal’s empty orbitals hybridise (sp3, dsp2, d2sp3 and so on), and each hybrid orbital accepts a lone pair from a ligand, which fixes the shape.
D. Crystal Field Theory — This matches IV. Electrostatic model which considers the metal-ligand bond as ionic. CFT treats the ligands as point charges (or dipoles), so the metal–ligand bond is taken as purely ionic.
Shortcut: The pair A–III appears in Options (2), (3) and (4), and B–I then leaves only Option (3).