Q.What are hydrate isomers? Explain with an example.

Step 1. Solvate isomers arise when a free solvent molecule in the crystal lattice (water, ammonia, alcohol, etc.) is exchanged with a ligand already inside the coordination entity; when that solvent is specifically water, the isomers are called hydrate isomers.

Step 2. The chapter's worked example is CrCl₃.6H₂O, which exists as three distinct hydrate isomers, differing in how many of the six water molecules are actually coordinated to chromium versus sitting free in the lattice.

Step 3. [Cr(H₂O)₆]Cl₃ (all 6 waters coordinated, 0 free) is violet and releases 3 Cl⁻ ions in solution, since all three chlorides are free counter ions.

Step 4. [Cr(H₂O)₅Cl]Cl₂.H₂O (5 waters coordinated, 1 free) is pale green and releases 2 Cl⁻ ions in solution, since one chloride is now bound inside the coordination sphere. …

Define hydrate isomers as the water-specific case of solvate isomerism, and use the chapter's own CrCl₃.6H₂O example, noting how coordinated-versus-fre …

• Assuming all three isomers of CrCl₃.6H₂O behave identically in solution -- they actually release different numbers of free Cl⁻ ions, which is exactly how they were distinguished experimentally (and how the Evaluate Yourself dehydration-mass-loss problem in this section works). …