Question

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

Answer 1

Once the POP has changed to hard substance it can't be reversed but if POP is added to water before it is hard it changes to Gypsum Again. POP can't be reversed if it has been set to hard mass.

Answer 2

$\textbf{No, }$ you can't change POP after drying into its initial form.

This is because it became hard on drying and new products is formed which can't be reversed.

You can also call it as a chemical reaction.

$\textbf{POP}$

It is prepared from gypsum. Gypsum is calcium sulphate dihydrate.

It is a white powder, and have a remarkable property of setting into a hard mass on wetting with water.