hydrate isomers are in CoCl_3.6H₂O are 3

can u explain how it,s so ..........

can it be 4 if not please explain......

Hydration Isomers exchange water as ligand and hydrate. For CoCl3.6H2O there are 3 hydrate isomers. They are

[Co(H2O)6]Cl3, [Co(H2O)5Cl]Cl2.H2O, and [Co(H2O)4Cl2]Cl.2H2O

For CoCl3.6H2O 4^th isomer is not formed as there are no further correct combination of solvate and the counter ions are possible (as the complex should form octahedral structure, i.e central metal ion bonded to 6 ligands).