Question

Plaster of Paris is___

• A. \(CaSO_4.2H_2O\)
• B. \(CaSO_4.H_2O\)
• C. \(CaSO_4.\frac{1}{2}H_2O\)
• D. \(CaSO_4\)

Answer 1

The Correct Option is C

To solve the problem, we need to identify the correct chemical formula for Plaster of Paris.

1. Understanding Plaster of Paris:
Plaster of Paris is a chemical compound that is obtained by heating gypsum (CaSO₄·2H₂O) to about 150°C. When heated, gypsum loses water molecules and becomes Calcium Sulfate Hemihydrate.

2. Chemical Formula of Plaster of Paris:
The formula for Plaster of Paris is:
\[ \text{CaSO}_4 \cdot \frac{1}{2}\text{H}_2\text{O} \]
This indicates that each unit contains half a molecule of water of crystallization.

Final Answer:
The chemical formula of Plaster of Paris is \({\text{CaSO}_4 \cdot \frac{1}{2} \text{H}_2\text{O}} \).