A student analyzed a CaCO3 antacid tablet by neutralizing the base with an excess of .60 M HCL and back-titrating the excess with .50M NaOH. He recorded the following data:

mass of tablet = 1.3g

amount of active ingredient CaCO3 per label = 500 mg

volume of HCl added: 25 mL

initial buret reading : 34 mL

final buret reading : 47.4 mL

A) Calculate the moles of H⁺ initially added.

B) Calculate the moles of H⁺ neutralized in the back-titration (that is, the excess H⁺)

C) Calculate the moles of H⁺ neutralized by the antacid tablet

D) Calculate the mass of CaCO3 in the antacid tablet based on the experimental data.

E) Calculate one percent error using the packaging information as the known value.