WBCS.LIVE practice question

What is the main chemical constituent of 'Plaster of Paris'?

Solve this multiple-choice question and check the correct answer with its explanation below.

Answer options

  1. Calcium carbonate
  2. Calcium hydroxide
  3. Sodium bicarbonate
  4. Calcium sulfate hemihydrate

Correct answer and explanation

Correct answer: Calcium sulfate hemihydrate

Explanation: ✅ Correct Answer: D) Calcium sulfate hemihydrate 📚 Explanation: Plaster of Paris is a quick-setting gypsum plaster consisting of a fine white powder. Its precise chemical name is calcium sulfate hemihydrate (CaSO₄·½H₂O). When it is mixed with water, it rapidly rehydrates and hardens back into solid gypsum, making it highly useful for medical casts and sculpting.