AI-generated practice question — model-generated for extra practice, not a previous-year CBSE board question.
Gypsum is a soft mineral (hydrated calcium sulphate) used in the production of Plaster of Paris. Its chemical formula is CaSO₄·2H₂O.
This question comes from the chapter on acids, bases and salts (Chapter 2), though it is not covered in the source passages provided. Gypsum is the standard one-line answer expected: name + formula. Remember that Plaster of Paris (CaSO₄·½H₂O) is made by heating gypsum — examiners often test the distinction between the two formulas.