Calcium sulfate (or calcium sulphate) is the inorganic compound with the formula CaSO4 and related hydrates. In the form of γ-anhydrite (the anhydrous form), it is used as a desiccant. One particular hydrate is better known as plaster of Paris, and another occurs naturally as the mineral gypsum. It has many uses in industry. All forms are white solids that are poorly soluble in water.
The compound exists in three levels of hydration:
The main use of calcium sulfate is to produce Plaster of Paris and stucco. These applications exploit the fact that calcium sulfate forms a moldable paste upon hydration and hardens as a hemihydrate. It is also convenient that calcium sulfate is very poorly soluble in water, so structures do not dissolve.
This page provides supplementary chemical data on calcium sulfate.
The handling of this chemical may incur notable safety precautions. It is highly recommend that you seek the material safety data sheet for this chemical from a reliable source and follow its directions.
Except where noted otherwise, data relate to standard ambient temperature and pressure.
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