1. If a student forms CaCO3 from the presence of carbon dioxide, but continued with the trial anyway, how

Question

would this affect his/her calculations (too high, too low, or no effect)? Explain your answers.
a) The volume of NaOH required for the back titration.
b) The calculated moles of HCl neutralized by the antacid.

2. A student performed Part II as outlined in the procedure, but when he added the bromophenol blue the
solution turned blue.
a) Why is the solution blue?
b) What can the student do to correct for this error and salvage this trial? How should the data sheet be
modified to reflect this correction?

Answer 1

too high