19. A compound which is prepared from gypsum has a property of hardening when mixed with water. I identify the compound and write its chemical formula. Write the chemical equation for its preparation. Mention any one use of the compound.

19. A compound which is prepared from gypsum has a property of hardeni

1.	19. A compound which is prepared from gypsum has a property of hardening when mixed with water. I identify the compound and write its chemical formula. Write the chemical equation for its preparation. Mention any one use of the compound.
Answer» d had on its PREPARATION