How many grams of CuSO4 are there in 100.0 g of hydrate? How many moles?

The hydrate form of CuSO4 has 5 water molecules (CuSO4-5H20) copper (II) Sulfate pentahydrate or commonly known as blue vitriol.

To solve, the following molar masses are to be known.

CuSO4.5H2O (hydrate) - 249.7g/mole

CuSO4 (anhydrous) - 159.6g/mole

Also there molar ratio of the hydrate and CuSO4 is 1.

the mass of the hydrate is to be divided by the molar mass of the hydrate then multiplied by the ratio (1) to get the moles of hydrate and multiplied by the molar mass of the anhydrous to get the mass in grams.

moles = (100g/249.7) * 1 = 0.4 moles hydrate

grams = 0.4*159.6 = 64.9 grames hydrate