Hemihydrate

{{Short description|Solid substance containing one water molecule per two unit cells}}

In chemistry, a hemihydrate (or semihydrate) is a hydrate whose solid contains one molecule of water of crystallization per two other molecules, or per two unit cells. This is sometimes characterized as a solid that has one "half molecule" of water per unit cell.{{Cite book |last=Kent |first=James A. |url=https://books.google.com/books?id=zPZWYerB3SYC |title=Kent and Riegel's Handbook of Industrial Chemistry and Biotechnology |date=2007-10-08 |publisher=Springer Science & Business Media |isbn=978-0-387-27842-1 |pages=1096 |language=en}} An example of this is calcium sulfate hemihydrate ({{chem2|CaSO4*0.5H2O}} or {{chem2|2CaSO4*H2O}}), which is the hemihydrate of calcium sulfate ({{chem2|CaSO4}}).