2. An 800.0 mg sample containing sulfate was treated with a slight excess of barium chloride, yielding a precipitate that contained 4.3 mg of co-precipitated BaCO,. After ignition and cooling, the precipitate weighed 377.0 mg. Calculate (a) the apparent % SO, (b) the true % SO, (c) the absolute error in % SO. Hint-BaCO, on ignition is converted to BaO & CO