posted by jas .
when 1.87 g of gypsum(hydrated calcium sulfate) was heated to constant mass, it lost 0.39 g of water. What is the formula of gypsum?
YOu know it is of the form: CaSO4.XH2O
the idea here is to find x.
calculate the number of moles of water in .39g.
Calculate the number of moles of CaSO4 in 1.87-.39 g.
divide the moles of water by the moles of CaSO4. That is x
Now, the lesson: Why is this so?