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Safe Substitute for HCl? pH 1-2. URGENT!!

Postby cch072405 » Sun Feb 16, 2020 1:14 pm

I am doing a science project regarding antacids, alkaline(base) substances, and the gastric system.
However, my teacher says working with hydrochloric acid (to represent stomach acid) would result in highly caustic and dangerous reactions, but vinegar or lemon juice are not close enough in pH to stomach acid.
is there a safe acid that has a pH of between 1-2?

Thank you! Please respond ASAP!

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Re: Safe Substitute for HCl? pH 1-2. URGENT!!

Postby charlesg » Sun Feb 16, 2020 5:19 pm

Hi cch072405,

Hydrochloric acid would be the closest simulation of stomach acid. You might be able to get an experienced adult to help you dilute the solution into 0.1M hydrochloric acid (pH value of 1.0), but you would still want to want to take all the necessary precautions when working with the solution (latex/nitrile gloves, goggles, avoid breathing in vapors).

Unfortunately, there are no other household acids I know of that have a pH of 1. Lemon juice and vinegar have pH values of 2-3, as you mentioned. Depending on the question you aim to answer, they might work well enough for your experiment.

Best of luck!

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Re: Safe Substitute for HCl? pH 1-2. URGENT!!

Postby cvionis » Sun Feb 16, 2020 5:57 pm

Hello cch072405,

As charlesg has addressed your question regarding the existence of alternative acids with a pH of 1–2, I would like to give some additional potentially beneficial advice for your experiment.

If you want to mimic stomach acid (gastric juice) in your experiment, then it may not be the best idea to use and/or represent only hydrochloric acid in place of it. This is due to the fact that hydrochloric acid is not the only component of stomach acid; stomach acid also contains potassium chloride, sodium chloride, mucus, and other substances. If you were to decide to represent stomach acid instead of using only hydrochloric acid in your experiment, then you could make your own "stomach acid" by mixing hydrochloric acid, sodium, potassium, and water. Doing this might reduce the amount of HCl you need in your experiment, potentially making it less of a hazard (though not significantly).

Here is a brief but helpful webpage describing how to mimic/simulate stomach acid: ... 56282.html. The following link describes the safety precautions that must be met while handling hydrochloric acid: ... fety-tips/.

I hope that these suggestions and links prove helpful; if you have any further questions or comments, please let me know.

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