Question

which of them is hard solid?

◆ gypsum
◆ plaster of paris

ty ( give the chemical formulas too )

Answer 1

gypsum is hard solid..
Gypsum is calcium sulphate dihydrate. The chemical formula of this compound iscaSo4 CaSO4.2H2O. On heating at 373 K, gypsum loses water molecules and becomes calcium sulphate hemihydrate, which is commonly known as Plaster of Paris(caSo4.1/2 H2O

Answer 2

gypsum is hard solid


chemical formula of gypsum: CaSO4·2H2O

chemical formula of plaster of paris:CaSO4·½H2O