AI-generated practice question — model-generated for extra practice, not a previous-year CBSE board question.
The chemical formula of Plaster of Paris is CaSO₄·½H₂O (calcium sulphate hemihydrate).
This question is from Chapter 2 (Acids, Bases and Salts), not Chapter 4. The source passages provided are from Chapter 4 (Carbon and its Compounds) and do not contain information about Plaster of Paris. However, the standard CBSE answer is CaSO₄·½H₂O. Examiners expect the correct formula with the half water of crystallisation clearly written. Some textbooks also write it as (CaSO₄)₂·H₂O — either form is accepted.