A thick coating of a paste of Plaster of Paris (POP) is applied over the bandage on a fractured bone. It becomes hard on drying to keep the fractured bone immobilised. Can the change in POP be reversed?

(1) No, this change cannot be reversed because getting it back is an irreversible change or a chemical change.

(2) The plaster of Paris on getting mixed with water changes into a hard mass and form a new compound.