The paste of a white material in water is used to maintain a fractured

The paste of a white material in water is used to maintain a fractured bone fixed in place. The white material used is called

bleaching powder
plaster of Paris
powder of zinc oxide
lime powder
This question was previously asked in
UPSC CDS-2 – 2017
The correct option is B) plaster of Paris.
Plaster of Paris is calcium sulfate hemihydrate (CaSO₄·½H₂O). When mixed with water, it forms calcium sulfate dihydrate (gypsum, CaSO₄·2H₂O), which is a hard solid. This property makes it ideal for creating casts to immobilize fractured bones, allowing them to heal properly.
Bleaching powder is primarily used for disinfection and bleaching. Zinc oxide is used in various applications including cosmetics, paints, and as a mild antiseptic. Lime powder (calcium oxide or hydroxide) is used in construction, agriculture, and chemical industries. Only plaster of Paris has the specific property of setting into a hard mass upon mixing with water which is used for medical casts.