Question

What is gypsum what happens when gypsum is heated to 100 degree C (373 K) chemical reaction

Answer 1

Gypsum is calcium sulphate dihydrate.
It loses water and turns into plaster of paris.
$CaSO_{4} .2H_{2}O-------\ \textgreater \ CaSO_{4} .1/2H_{2}O+1 \frac{1}{2} H_{2}O$