A student obtains a 10.0g sample of a white powder labeled as BaCl2. After completely dissolving the powder in 50.0mL of distilled water, the student adds excess Na2SO4(s), which causes a precipitate of BaSO4(s) to form, as represented by the equation above. The student filters the BaSO4(s), rinses it, and dries it until its mass is constant. Which of the following scientific questions could best be answered based on the results of the experiment?
(A) Is the Na2SO4(s) used in the experiment pure?
(B) Is the BaCl2(s) used in the experiment pure?
(C) What is the molar solubility of BaCl2 in water?
(D) What is the molar solubility of BaSO4 in water?