Solvation is the term used to describe the interaction between a solution particle and solvent molecules. Solvation sometimes is so powerful that, when a solute forms from a solution, it incorporates strongly bonded molecules of solvent.
An example would be copper sulfate, that interacts with water so strongly that even if the solvent is evaporated to dryness, it retains water in the solid form: copper sulfate pentahydrate, CuSO45H2O.
