Why is solvation considered a surface phenomenon?

1 Answer
Mar 13, 2014

Solvation is a surface phenomenon in the sense that it starts at the surface of a dissolving solid.

During solvation, the particles of a solute become surrounded by solvent particles as they leave the surface of a solid. The solvated particles move into the solution.

For example, water molecules pull sodium and chloride ions from the surface of a sodium chloride crystal. The solvated Na⁺ and Cl⁻ ions end up in the solution.

![Solvation with sodium and water molecules from http://www.oceanclassrooms.com.](http://www.oceanclassrooms.com/resources/images/moodlecourses/ms101/unit3/salt_dissolving.jpg)

We also use the term solvation when water molecules surround polar groups on the surfaces of cell membranes.