The chemical name of Plaster of Paris is Calcium Sulphate Hemihydrate. Since it is formed by using Gypsum (colorless minerals) which is mostly found in Paris that is why it is called Plaster of Paris.

Representation of a substance plaster of Paris using symbols is CaSO4.1/2 H2O while its chemical formula is written as (CaSO4)2.H2O.

(As simple structural unit of element or particle can’t be presented in ratio, therefore the formula of plaster of Paris can be written as CaSO4.1/2H2O. Here ½ particles are only written for your comfort and suitability.)

Manufacturing of Plaster of Paris

To prepare Plaster of Paris, Gypsum (CaSO4.2H2O is boiled in a Furnace at the temperature of 100 degree centigrade. Gypsum should be boiled attentively in a manageable state as if it is boiled more than 100 degree centigrade than a ‘Dead burnt plaster’ named Calcium Sulphate CaSO4 is produced which on mixing water does not adjust like Plaster Of Paris.

Features of Plaster of Paris

It is of white color in a pulverize form. Clear transparent crystalline mineral called Gypsum is produced which become stiff or firm matter on mixing 1/3 portion of water. Its adjusting limit can be enhanced by mixing salt (NaCl).On providing temperature more than 200 degree centigrade to gypsum, it creates a hydrous form of POP known as dead burnt plaster. This does not have the quality to adjust like plastic of Paris on mixing water.

Uses of Plaster of Paris

It is used in making objects for worship, playing objects for kids, forming sculptures representing a human or animal, making partial or complete set of artificial teeth for either the upper or lower jaw, fixing broken bones and adjusting joints, filling up air spaces in laboratory equipments while performing experiments, making ornaments, chalks (Calcite), make up products and POP false ceiling.

use of plaster of paris