Question

What is the difference in the formula of "Gypsum" and "Plaster of Paris"? Are they both same?

Answer 1

Gympsum -CaSO4. 2H2O
plaster of paris-CaSO4. 1/2H2O

when plaster of Paris comes in contact with water or moisture it forms gypsum
Caso4 .1/2H2O +1 1/2 H20. GIVES CaSo4.2H20

when gypsum is heated it forms plaster of Paris

Answer 2

Gypsum : CaSO4•2H2O
Plaster of Paris : CaSO4•1/2 H2O + 1• 1/2H2O
No, Gypsum and plaster of Paris are not same when gypsum is heated it losses it 1• 1/2 molecules of water and this lead to formation of POP.