Chemical formula of gypsum is

CaSO₄·2H₂O.

Calcium Sulphate dehydrated is called gypsum.

The chemical formula is $CaS{O}_{4}2H_{2}O$.

It is the main constituent of plaster of paris.

It is selenite ,a variety of gypsum with colourless, clear crystals.

Gypsum Formula and Chemical Name

• The chemical formula of gypsum is CaSO₄·2H₂O.
• Its chemical name is Calcium Sulfate Dihydrate, which indicates it contains two water molecules of crystallization.

Gypsum Formula Reaction

Gypsum is naturally found as a mineral in sedimentary rocks and can also be synthesized.
When heated to approximately 120°C, gypsum loses water molecules to form Plaster of Paris:

This reaction shows how Plaster of Paris (CaSO₄·½H₂O) is derived from gypsum.

Gypsum Formula Structure

• Gypsum consists of a calcium ion (Ca²⁺), sulfate ion (SO₄²⁻), and two water molecules.
• It forms a crystalline structure with water molecules bound within.

Comparison Between Gypsum and Plaster of Paris Formulas

Gypsum Uses

1. Construction: Used in making drywall, plaster, and cement.
2. Fertilizers: Acts as a soil conditioner to improve crop yields.
3. Medical: Used in making surgical splints and casts.
4. Art: Essential in molds and sculptures.