Question

How is plaster of Parish prepared? Write chemical equation of the reaction involved.

Answer 1

When gypsum (CaSO₄.2H₂O) is heated to a temperature of 100^⁰C (373K), it loses three-fourths of its water of crystallisation and forms plaster of Paris. ​

CaSO₄.2H₂O Δ → CaSO₄.1/2H₂O + 3/2 H₂O

 Gypsum           Plaster of Paris