GC Acids Bases Salts

Which one of the following is the number of water molecules that share with two formula unit CaSO4 in Plaster of Paris?

  1. One
  2. Two
  3. Five
  4. Ten

Answer

Plaster of Paris is CaSO4.½H2O

So, two formula units of CaSO4 share one molecule of water.

The correct option is A.