JEE Main 17 March 2021 Shift 2 Solved Paper

A. Coordination isomerisms occurs in coordination salts in which there is an interchange of ligands between the metal in the cationic coordination spheres and the metal in the anionic coordination sphere.
[Co(NH3)6][Cr(CN)6]⇔[Co(CN)6][Cr(NH3)6] (Coordinate isomerism)
B. Linkage isomerism occurs in coordination compounds that have the same composition but differ in the connectivity of the ligand to the metal. [Co(NH3)3(NO2)3] shows linkage isomerism. NO2 can connect through N and O donor sites.
C. Solvate isomerism is also known as 'hydrate isomerism' where water behaves as a ligand and water of crystallisation. e.g., The complex [Cr(H2O)6]Cl3 (violet) contains water as a ligand and its solvate isomer [Cr(H2O)5Cl]Cl2H2O (grey- green) contain water as a water of crystallisation.
D. Optical isomerism occurs mainly in compounds that are mirror images of each other. cis[CrCl2(ox)2]3+ is chiral compound, hence shows optical isomerism.