Ascorbic acid (vitamin C) is a diprotic acid having the formula H2C6H6O6. A sample of a vitamin supplement was analyzed by titrating a 0.2801 g sample dissolved in water with 0.0399 M NaOH. A volume of 13.68 mL of the base was required to completely neutralize the ascorbic acid. What was the percentage by mass of ascorbic acid in the sample?
?% ascorbic acid
An ore of barium contains BaCO3. A 3.401 g sample of the ore was treated with HCl to dissolve the BaCO3. The resulting solution was filtered to remove insoluble material and then treated with H2SO4 to precipitate BaSO4. The precipitate was filtered, dried, and found to weigh 3.243 g.
What is the mass of barium in the sample?
What is the percentage by mass of barium in the ore? (Assume all the barium is precipitated as BaSO4.)
How many moles of barium were in the sample?