Using the equivalent millimoles HCl/mg sample, the stoichiometry of reaction of HCl with NaOH (which I know is 1:1), and the molar mass of the hydroxide ion, report the gram equivalent OH- per gram of ...there is moreshow problem
Using the equivalent millimoles HCl/mg sample, the stoichiometry of reaction of HCl with NaOH (which I know is 1:1), and the molar mass of the hydroxide ion, report the gram equivalent OH- per gram of antacid for each of the three trials.
mass of each tablet-1.211g
mass antacid Vol HCl(mL) Vol NaOH(mL) mmol HCl/mg sample
#1: 1.314g 25.09 24.58 0.001550
#2: 1.316g 25.07 24.29 0.001582
#3: 1.315g 25.03 24.80 0.001509
I then must convert the gram equivalent OH-/gram antacid to % equivalent OH-.© BrainMass Inc. brainmass.com October 16, 2018, 10:43 pm ad1c9bdddf
This solution details how to find the % equivalent OH- of an antacid. The antacid is treated with acid. The excess acid is then titrated with sodium hydroxide. The volumes of these two solutions are then used to find the neutralizing power of the antacid.
Determine the strength of 5 antacids via addition to a known amount of acid, followed by titration with base. Determine which is most effective per dose and per gram.
Imagine yourself as the Lead Analytical Chemist at Kaplan Industries. Your first big assignment is to investigate the strength of several commercial antacids for the Food and Drug Administration (FDA). They have sent five antacids to be tested with a back-titration that works as follows:
? First, each antacid tablet is mixed with 40 mL of 0.1 M HCl?this acidic solution is the same stuff that is in stomach acid, and one antacid pill isn't anywhere near enough to neutralize all 40 mL of the acid.
? So, to see how much extra help each antacid pill needs to neutralize 40 mL of 0.1 M HCL, you add 0.05 M NaOH drop-by-drop to back-titrate the solution until the pH is neutral.
? What this means is that, the stronger the antacid tablet, the less NaOH it will take to help bring the acid to neutral. (In other words, the stronger antacid tablets counteract more of the original HCl, leaving the solution closer to neutral before the NaOH is added.)
Here are your results:
Maalox Tums Mylanta CVS brand Rennies
Mass of one dose
antacid 20.0 g 21.0 g 18.0 g 18.3 g 17.5 g
mL NaOH used in back-titration 24.1 mL 22.4 mL 20.0 mL 19.9 mL 24.4 mL
1. Which is the strongest antacid, on a single-dose basis? Which is the weakest? Explain and show your calculations.
2. Which are the strongest and weakest, on a by-weight (mass) basis?
3. When people do back titrations, they usually watch the solution for a color change when the solution becomes neutral. What might you have used in the above experiment to get this color change to happen in the solution? At what pH would the solution have been neutral?
4. If you had walked into the lab, only to discover that you only had 0.1 M sulfuric acid available to run your tests, how might this have affected your calculations? Why?
5. In most of the antacids you tested, the active ingredient is Aluminum Hydroxide. Here is an unbalanced reaction that shows how this chemical neutralizes HCl (the main ingredient in stomach acid). Please provide a balanced version of this equation:
Al(OH)3 + HCl --> AlCl3 + H20
6. The FDA requires that all of its reports be super-brief?short enough so that they can be sent via text message to all of its lab sites across the country.. As you probably know, the word limit for text messages is very small, so your goal here is to describe precisely what you did to test the antacids in fewer than 150 words. In this brief report, you should provide the FDA the major findings from your tests and let them know generally how you performed your tests.