Plaster of Paris is made by calcining gypsum (CaSO4.2H2O). This process involves heating gypsum to very high temperatures to form calcium sulphate. The calcium sulphate so formed is then grinded to powder. When water is added to this powder, a slurry is formed with the release of heat according to the equation: | Plaster of Paris is made by calcining gypsum (CaSO4.2H2O). This process involves heating gypsum to very high temperatures to form calcium sulphate. The calcium sulphate so formed is then grinded to powder. When water is added to this powder, a slurry is formed with the release of heat according to the equation: |