Question

Identify the correct statement

• A. Plaster of paris is obtained by heating gypsum
• B. Gypsum is obtained by heating plaster of paris
• C. Plaster of paris can be obtained by hydration of gypsum
• D. Plaster of paris is obtained by partial oxidation of gypsum

Answer 1

The correct option is A Plaster of paris is obtained by heating gypsum

Plaster of paris is prepared by heating Gypsum. When we heat the gypsum, it loses water molecule and forms calcium sulphate hemihydrate. The reaction will be
$\underset{\left(\text{Gypsum}\right)}{CaS{O}_4.2H_{2}O}\stackrel{373K}{\to }\underset{\text{(Plaster of Paris)}}{CaS{O}_4.\frac{1}{2}{H}_{2}O+1\frac{1}{2}{H}_{2}O}$