Which one of the following is the chemical formula of gypsum?

Which one of the following is the chemical formula of gypsum?

CaSO₄·2H₂O
Ca₂SiO₄
2CaSO₄·H₂O
CaSO₄
This question was previously asked in
UPSC NDA-2 – 2018
Gypsum is a mineral commonly found in evaporite deposits. Its chemical composition is calcium sulfate dihydrate, meaning it contains calcium sulfate (CaSO₄) and two molecules of water of crystallization per formula unit. The chemical formula for gypsum is CaSO₄·2H₂O.
The degree of hydration of calcium sulfate determines whether it is gypsum (dihydrate), plaster of Paris (hemihydrate), or anhydrite (anhydrous).
When gypsum (CaSO₄·2H₂O) is heated, it loses water to form calcium sulfate hemihydrate (CaSO₄·½H₂O), which is commonly known as Plaster of Paris. Further heating removes all water, resulting in anhydrous calcium sulfate (CaSO₄), or anhydrite. Gypsum is widely used in plaster, drywall (gypsum board), cement production, and as a soil conditioner.
Exit mobile version