A student grinds up an antacid tablet that weighs 1.42 grams. The antacid contains CaCO3 as the primary active ingredient. The resulting powder is added to 15.00 mL of 1.00 M HCl solution. The mixture is then heated, cooled, and titrated with 0.950 M NaOH solution from a buret. The initial buret reading is 7.85 mL; at end point, the buret reading is 13.65 mL.
6. Calculate the initial number of moles of HCl in 15.00 mL of the 1.00 M HCl solution. (3 sig figs)
7. Calculate the number of moles of EXCESS HCl that were left over after the antacid tablet was used up and then neutralized by the NaOH solution in the titration.
8. Calculate the number of moles of HCl that were used up (neutralized) by the antacid.
9. Calculate the number of moles of HCl neutralized per gram of antacid.
10. The balanced reaction of the active ingredient with HCl is: 2 HCl + CaCO3 ---> CaCl2 + CO2 + H2O. Calculate the mass of the active ingredient in the tablet.
11. If a box of the antacid used in the example above costs $2.38, contained 75 tablets and the average mass of the tablet is 1.42 g/tablet, what is the cost of the antacid in � per tablet and in � per gram?
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