Calcium sulphate hemihydrate is commonly known as plaster of Paris. The name is derived from the place of its origin Montmartre in the Paris district. The chemical formula is .
Preparation of plaster of Paris:
When gypsum (), is heated in a rotating kiln at \(300\), it loses its water molecule and forms calcium sulphate hemihydrate.
Properties of plaster of Paris:
- It is a white powder.
- It acts as an oxidizing agent under extreme conditions.
- It produces gypsum when mixed with water.
Uses of Plaster of Paris:
Uses of plaster of Paris
- It is used in making casts for statue, dentistry, surgical instruments, and toys etc
- It is used in construction for making smooth walls, and in the creation of walls and ceilings designs.
- It is used in making chalks and also helps in setting fractured bones during surgery.
- In laboratories, it is used to seal air gaps in the apparatus.