Each copper (II) sulfate unit is associated with five water molecules in crystalline copper (II) sulfate pentahydrate (CuSO4 ⋅ 5H2O). When this compound is heated in air above 100oC, it loses the water molecules are also its blue color:
CuSO4 ⋅ 5H2O → CuSO4 + 5H2O
If 9.60 g of CuSO4 are left after heating 15.01 g of the blue compound, calculate the number of moles of water originally present in the compound.