what is meant by plaster of Paris
Answers
Explanation:
It is the compound of calcium which is used for plastering of lecture bones is calcium sulphate hemihydrate(calcium sulphate half- hydrate)
★ it is also called plaster of paris.
The formula of plaster of Paris is
CaSO4.1/2H2O
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the name plaster of Paris. came from that fact it was first of all made by heating gypsum which is mainly found in Paris..
it is commonly known as P.O.P.
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Chemical equation:
........................... heat to(100°c)
2(CaSO4.2H2O)-------------------->
2CaSO4.H2O. + 3H2O.
here reactant is gypsum.
it is heated on temperature 100°c.
then product obtained is plaster of Paris and water.
Precautions.
→ in the preparation of plaster of Paris heating of gypsum should be controlled carefully.
→ the temperature during the heating of gypsum should not be allowed to go above 100° c.
→ this is because if the gypsum is heated above 100 degree Celsius then its water of crystallization is eliminated and anhydrous calcium sulphate (CaSO4) called dead burnt plaster is formed.
→ The anhydrous calcium sulphate does not set like plaster of Paris on adding water.