Describe plaster of Paris mentioned the name of raw material with their uses. And why calcium sulphate hemi hydrate called plaster of paris
Answers
Answer:
Plaster of paris, quick-setting gypsum plaster consisting of a fine white powder (calcium sulfate hemihydrate), which hardens when moistened and allowed to dry.Known since ancient times, plaster of paris is so called because of its preparation from the abundant gypsum found near Paris.
The materials used to make it are
calcium sulphate with half molecule of water of crystallization (CaSo4. ½ H2 o) and hygroscopic characteristics obtained by duly calcined the raw material i.e. Gypsum (CaSo4 2H2o).
Gypsum contains calcium sulfate dihydrate (CaSO4·2H2O) and plaster of Paris contains calcium sulfate hemihydrates (CaSO4·0.5 H2O).Plaster of Paris (PoP) can be moulded into different shapes when it is moistened, but gypsum does not have that property
I have not understood this question properly but i hope that the answers i gave will satisfy your curiosity