Question

A white powder which sets hard on adding water is also used in hospitals. Name this powder. How is it prepared? Write the chemical reaction involved in its preparation.

Answer 1

Answer:

Calcium sulphate(CaSO4.1/2 H2O) with half a water molecule of water is used in these things. It's common name is plaster of paris.

Answer 2

The white powder which hardens on mixing with water and used in hospitals is commonly known as Plaster of Paris. This is used for plaster casts which hold broken arms or legs of patients in place and allow the broken bones to set and heal.

The chemical formula for Plaster of Paris is CaSO4 -1/2 H2O (Calcium Sulphate Hemihydrate). It is made by heating gypsum to a high temperature which then becomes a dry white powder. When this dry powder is mixed with water, it forms a paste that hardens later. It is the hydrogen bonds in the water molecules that hold together the hard plaster.