Class 12 NEET Chemistry Coordination Compounds

Concept:Coordination compounds show different isomerism types based on ligand arrangement, bonding mode, or hydration.Chemical Equation / Formula:A: $[\mathrm{Pt}(\mathrm{NH}_3)_2\mathrm{Cl}_2]$B: $[\mathrm{Co}(\mathrm{en})_3]^{3+}$C: $[\mathrm{Co}(\mathrm{NH}_3)_5\mathrm{NO}_2]\mathrm{Cl}_2$D: $[\mathrm{Cr}(\mathrm{H}_2\mathrm{O})_6]\mathrm{Cl}_3$Explanation:A is square planar $\mathrm{Pt}^{2+}$ ($d^8$).It shows geometrical (cis-trans) isomerism → matches III.B is octahedral with three bidentate $\mathrm{en}$ ligands.Lacks a plane of symmetry → shows optical isomerism → matches I.C contains ambidentate $\mathrm{NO}_2^-$ ligand.It can bind through N (nitro) or O (nitrito) → linkage isomerism → matches IV.D can exchange $\mathrm{Cl}^-$ with $\mathrm{H}_2\mathrm{O}$ molecules.Forms hydrates → solvate isomerism → matches II.Shortcut:Square planar $\mathrm{MA}_2\mathrm{B}_2$ → geometrical.$[\mathrm{M}(\mathrm{AA})_3]$ → optical.Ambidentate ligand → linkage.Hydrate exchange → solvate.Answer:Option D (A‑III, B‑I, C‑IV, D‑II).