Question

Gypsum when heated with 373 k

Answer 1

When we heat gypsum with 373K then plaster of Paris formed which is white powder.

Answer 2

Gypsum is a soft mineral of sulphur that contains water of crystallization and is represented by $CaSO_4. 2H_2O$. When gypsum is heated at 373 K, it loses its water of crystallization or all the water molecules and becomes calcium sulphate hemihydrate. Gypsum is converted to “Plaster of Paris”. In fact, gypsum is Plaster of Paris and when heated, this Plaster of Paris melts to give Gypsum.

On being further heated beyond 373 K, gypsum gives a product known as Gamma “Anhydrite”.