1. Gypsum is a mineral, or natural substance that is a hydrate of calcium sulfate CaSO4. A 1.000g sample of gypsum contains 0.791g of CaSO4. How many moles of CaSO4 are there in this sample. Assuming that the rest of the sample is water, how many moles of H2O are there in the sample?
2. A 1.547g sample of blue copper (II) sulfate pentahydrate CuSO4~5H2O is heated carefully to drive off the water. They white crystals of CuSO4 that are left behind have a mass of 0.989g. How many moles of H2O were in the original sample?