Question

243. How will you prepare plaster of Paris?

Answer 1

• Plaster of Paris is also known as Calcium sulfate hemihydrate.
• The chemical formula of plaster of Paris is CaSO₄.1/2 H₂O.
• Plaster of Paris can be prepared by heating gypsum at 150°C temperature.
• Gypsum is also known as Calcium sulfate dihydrate and its chemical formula is CaSO₄.2H₂O.
• The chemical equation for the reaction of formation of plaster of Paris is as follows:

${\mathrm{CaSO}}_4.2{\mathrm{H}}_2\mathrm{O}\stackrel{100°\mathrm{C}}{\to }{\mathrm{CaSO}}_4.\frac{1}{2}{\mathrm{H}}_2\mathrm{O}+1\frac{1}{2}{\mathrm{H}}_2\mathrm{O}$

Gypsum Plaster of Paris Water