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Homework Help: Help with a chemistry lab-I suck at it.

  1. Apr 29, 2007 #1
    I have to design and conduct an experiment to test the effectiveness of 4 different kinds of antacids on neutralizing HCl (stomach acid).

    I could do this if you gave me the procedure but I have to completely design an experiment.
    I suck at chemistry and this is all going over my head.
    I was thinking about doing something with titrations but I dont know exactly how to go about that.

    Would I put the antacid is a flask, and then titrate it with HCl?

    Someone PLEASE help me.
    Clearly, chemistry is not my thing.
  2. jcsd
  3. Apr 29, 2007 #2
    Okay what I have so far is:
    You put the acid in the burette(?)
    base (antacid) in the flask.

    VolumeXConcentration of HCl / Volume of antacid = Concentration of the antacid

    1-how do you measure the volume of a solid antacid?
    2-how do you know how much HCl has been neutralized?

    I have to figure this out in 2 days.
  4. Apr 29, 2007 #3


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    You have the right idea. You would most likely measure the mass (not volume) of the antacid tablet. Try using some fraction of the sample size recommended by antacid instructions. What pH will you get after the neutralizing ability of the antacid tablet has been exhausted? How might you measure this pH?
  5. Apr 29, 2007 #4
    wouldnt you put an indicator in the flask so you know when its been neutralized

    but if I have a solid antacid, how would I do that?
    Would I add water to the antacid and then put indicator in it?
  6. Apr 29, 2007 #5


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    You are better at this than you think....
  7. Apr 30, 2007 #6
    ive been looking all over the internet trying to figure it out

    so adding water to the antacid wouldnt mess it up or anything would it?
  8. Apr 30, 2007 #7


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    No. You could also add acid (measured amount) in excess to the antacid tablet and titrate the excess acid with a base titrant (NaOH, 0.1N). How much excess acid to add would be something for you to figure out after a few preliminary tests with indicator solution. Use this method if the tablet dissolves slowly or not at all. Calcium carbonate could be a component, for example, and will not dissolve in the water you add.
  9. May 1, 2007 #8
    I think tums is calcium carbonate.
    Im pretty sure Ive figured out exactly what Im going to do.
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