The purpose of this experiment was to determine the CaCO3 content of an an-acid pill. We determined that the percent CaCO3 content in our experiment was 10.32%. This was determined by calculating the CaCO3 consumed in the sample then by using the stoichiometric ratio 2:1 we determined the content present in the sample. The reason we used that ratio is because HCl reacts with CaCO3 in a 2:1 ratio. According to the bottle, each pill has 0.500g of CaCO3 meaning that the nominal CaCO3 content is 38.5% so there must have been significant errors in our experiment.
Percent Error:
(0.385gCaCO3 - 0.1032gCaCO3/0.385gCaCO3)x100=73.19% error
Some sources of error in this lab include, using standardized solutions of NaOH or HCl that did not have a molarity of at least 0.9M. Another source may have been not grinding the pill into fine powder or not measuring the correct amount specified in the directions. Another error could have occurred if the flask with the solution was not heated properly or stirred, which may have caused some of the chemicals to not react. Finally, the most common source of error is not letting the flask cool to room temperature before titrating.