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Name: teresa
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I want to do an experiment to see which antacid works best.How can I simulate stomach acid? Should I mix acidic foods like vinegar and orange juice together. I don't have access to chemicals like HCl unless it is available in something I'm not aware of.

Try muriatic acid which you can buy at the hardware store.

Hi Daniel...a solution of hydrochloric acid is not so difficult to get...try asking your science teacher at school.

But if your idea is to compare antiacids only by their antiacidic effect maybe you can do some experiments with other acids that you find at the kitchen, like as you said orange or lemon juice (citric acid) , vinegar (acetic acid).Be aware that even if you get a solution of hydro- chloric acid you are not reproducing the "real" conditions of the stomach or the gastric juice, since there are other substances involved, like the enzimes. But in any case you must have a way to show the resultant pH, like seeing the color with a Litmus paper. Hope that this answers your question, and thanks for asking Newton.

(Dr. Mabel Rodrigues)

Vinegar would be a good chemical to use to test antacids. Use the distilled white vinegar.

It's dangerous to work with, but you or your parents could probably get fairly concentrated hydrochloroc acid at the hardware store. It's sold as "muriatic acid," and it is marketed for cleaning bricks and concrete. You would have to dilute it to reach the strength of stomach acid - stomach acid at its strongest is about pH 1, which is 0.1 moles/liter HCl. The muriatic acid sold in the store is I think 40% HCl by weight. You would need to find its density and figure its concentration in moles/liter, so that you could calculate how much to dilute it to model stomach acid.

Richard Barrans Jr., Ph.D.

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