c) Insoluble salts are made by precipitation. An equation for the preparation of barium sulfate is given below. BaCl2jag) + MgSO stag) → BaSO. + Mg Claa) This reaction can be used to find x in the formula for hydrated magnesium sulfate MgSO4.XH2O. A known mass of hydrated magnesium sulfate, MgSO4.XH20, was dissolved in water. Excess aqueous barium chloride was added. The precipitafe of barium sulfate was filtered, washed and dried. Finally it was weighed. Mass of hydrated magnesium sulfate = 1.476 g Mass of barium sulfate formed = 1.398 g The mass of one mole of BaSO4 = 233 g​