Question

A compound which is prepared from gypsum has the property of hardening when mixed with proper quantity of water.
(a) Identify the compound
(b) Write the chemical equation for its preparation
(c) Mention one important use of this compound.

Answer 1

The compound which is prepared from gypsum which has the property of hardening when mixed with proper quantity of water is called plaster of Paris having the formula $Ca{SO}_4.\frac{1}{2}{H}_{2}O$.

(b) The chemical equation for the preparation of plaster of Paris is

$Ca{SO}_4.2H_{2}O\underset{}{\overset{373K\Delta }{\to }}Ca{SO}_4.\frac{1}{2}{H}_{2}O$

Plaster of Paris is prepared by heating gypsum at $373K$.

(c) One of the important use of plaster of Paris is that it is used by doctors as a plaster for supporting fractured bones in the right position.