Chemistry Unit 8 Final Project

772 Words4 Pages
Running Head: UNIT 8 Final Project Unit 8 Final Project Tammy Barker Kaplan University SC 155-01 Professor Leonard August 26, 2012 From what I see, technically, this is not a back-titration, because base (antacid) is being added to acid, more base is added to the acid until the equivalence point is reached. Wouldn’t a back- titration involve going past the equivalence point with base and then back titrating with acid until equivalence was reached? Then, with each case I am reacting the antacid and base with .040L (the 40mL) of 0.1M HCl, and molarity times volume giving moles as follows: (.040L HCl)*(0.1 mol HCl/L HCl) = .004 mol HCl. So in each case, in order to get to the equivalence point in this reaction of a strong acid with a strong base, I need to have .004 mol of base to fully react in a 1:1 ratio with the acid that's present. The combination of antacid and base that is added will add up to .004 mol. 1. Since I am adding the antacid first, and then adding the same .05 M NaOH to get to equivalence, whichever antacid neutralizes the most base (ie- is the strongest) will require the least amount of extra base to reach equivalence. That would be the CVS brand, at .0199L (for simplicity, all volumes will be expressed in L, even though the chart is in mL). The weakest would require the most extra base, and that would be the Rennies, at .0244L. Worked out as follows: (.0199L NaOH)*(.05 mol NaOH/L NaOH) = .000995 mol NaOH .004 mol base required - .000995 mol from NaOH = .003005 mol base from CVS antacid (.0244L NaOH)*(.05 mol NaOH/L NaOH) = .00122 mol NaOH .004 mol base required - .00122 mol from NaOH = .002780 mol base from Rennies antacid All other volumes fall in the categories

More about Chemistry Unit 8 Final Project

Open Document