Question

When the powder of Plaster of Paris is mixed with water, it becomes hard and solid gypsum, so can't we heat it to again form P.O.P in powder form?

Answer 1

Dear student!

Actually, plaster of paris is produced originally by heating gypsum at about 300 °F or nearly 150 °C as:

2CaSO₄ .H₂O + Heat --> 2CaSO₄ .1/2 H₂O + 3/2 H₂O

Here water is released in the from of steam.

Now , when the plaster of paris again absorbs water to convert into plaster of gypsum, then it may be further heated to get plaster of paris as above process.