When gypsum is heated to 393 K, it forms :
Show Hint
- \(\mathrm{CaSO_4 \cdot 0.5H_2O}\)
- \(\mathrm{CaSO_4 \cdot 5H_2O}\)
- Dead burnt plaster
- Anhydrous \(\mathrm{CaSO_4}\)
The Correct Option is A
Solution and Explanation
On heating to 393 K: 2(CaSO4.2H2O) → 2CaSO4.H2O + 3H2O, i.e. plaster of Paris, CaSO4.0.5H2O (hemihydrate).
Dead burnt plaster (anhydrous CaSO4) forms only on heating above about 473 K.
Answer: (1) CaSO4.0.5H2O
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