Science, Tech, Math › Science Water of Hydration Definition Print These are blue crystals of copper sulfate pentahydrate, which is known as copper sulphate pentahydrate in the UK. Anne Helmenstine Science Chemistry Chemical Laws Basics Molecules Periodic Table Projects & Experiments Scientific Method Biochemistry Physical Chemistry Medical Chemistry Chemistry In Everyday Life Famous Chemists Activities for Kids Abbreviations & Acronyms Biology Physics Geology Astronomy Weather & Climate By Anne Marie Helmenstine, Ph.D. Anne Marie Helmenstine, Ph.D. Chemistry Expert Ph.D., Biomedical Sciences, University of Tennessee at Knoxville B.A., Physics and Mathematics, Hastings College Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels. Learn about our Editorial Process Updated on June 07, 2018 Water of hydration is water that is stoichiometrically bound into a crystal. While the water is found within a crystal, it is not directly bonded to a metal cation. Crystal salts containing water of hydration are called hydrates. Also Known As: water of crystallization, crystallization water How Water of Hydration Forms Many crystals form from particles dissolved in water or aqueous solutions. It's common for some of that water to be incorporated into the framework of a crystal. Usually, heating a crystal drives off water of hydration, but the structure of the crystal is lost. Water of Hydration Example Read More Water of Crystallization Definition By Anne Marie Helmenstine, Ph.D. Commercial root killers often contain copper sulfate pentahydrate (CuSO4·5H2O) cyrstals. The five water molecules are called water of hydration. Proteins typically contain around 50 percent water within their crystal lattice. Nomenclature Water of hydration may be indicated a few different ways: (1) For a compound consisting of a hydrate with coordinated water, the formula is written: hydrated compound(H2O)n Example: ZnCl2(H2O)4 (2) When a compound contains lattice water, but its stoichiometric ratio changes or is unknown, the formula may be written simply: hydrated compound·nH2O Example: CaCl2·2H2O (3) The notations may be combined: Example: [Cu(H2O)4)SO4·H2O Cite this Article Format mla apa chicago Your Citation Helmenstine, Anne Marie, Ph.D. "Water of Hydration Definition." ThoughtCo, Aug. 25, 2020, thoughtco.com/definition-of-water-of-hydration-605787. Helmenstine, Anne Marie, Ph.D. (2020, August 25). Water of Hydration Definition. Retrieved from https://www.thoughtco.com/definition-of-water-of-hydration-605787 Helmenstine, Anne Marie, Ph.D. "Water of Hydration Definition." ThoughtCo. https://www.thoughtco.com/definition-of-water-of-hydration-605787 (accessed April 26, 2024). copy citation