Solvation is not an accepted term in the dictionary produced by the Royal Spanish Academy (RAE). It is a concept that is often used in the field of chemistry with reference to the process that involves the attraction and association of the ions of a solute and the molecules of a solvent.
To understand the notion, therefore, we must first know what other terms refer to. A homogeneous mixture composed of a solvent (also known as a solvent) and one or more solutes is called a solution. In this mixture, the solutes dissolve in the solvent: thus, there is a higher level of solvent than solutes in the solution.
When the solute ions dissolve, solvation occurs. These ions separate from each other and begin to be surrounded by the molecules that make up the solvent. The solvation of the ion is linked to its size, since the amount of solvent molecules that surround it depends on it.
It can be said that solvation occurs from the interactions of a solute with a solvent, which lead to the stabilization of the solute in the solution. The process requires that the ions of the crystal lattice be released: for this, the attraction that exists between the ions due to the lattice energy is needed. Solute ions, by associating with solvent molecules, release a class of energy called the free energy of solvation.
It is important not to confuse the concepts of solubility, dissolution and solvation, although they may have certain similarities to the naked eye. While dissolution refers to the addition of solute in a solvent, or to increasing the percentage of solvent in a certain previously existing solution, the term solubility refers to the maximum amount of solute that can be added to the solvent before its formation is precipitated, that is, a surplus of undissolved solute is formed.
Another concept that comes into play in this context is that of
This process of ion solvation results in the system stabilizing. Among the best known polar solvents, water is in the first place, since it is the one that has been studied the most and the easiest to find in nature; This group also includes dimethyl sulfoxide, acetonitrile, methanol, ammonia, acetone, ethanol and propylene carbonate. They can be used for the dissolution of salts, among other inorganic compounds.
There is more than one type of molecular interaction that takes place during solvation: ion-dipole, hydrogen bridge, London forces, or dipole-dipole attraction. Except London forces, the rest are only found in polar solvents. The ion-ion, for their part, occur in ionic solvents (a possible case is the molten phase).