Alternative to Hydrochloric Acid???URGENT

[Gill94]

Im doing an experiment where im testing the dissolution rates for different pain relievers and since i cant use hydrochloric acid to dissolve the pain relievers in, what could be a good alternative???

[barretttomlinson]

Hi,

Why were you wanting to use hydrochloric acid as a solvent, and why can’t you? I am guessing you wanted to simulate the gastric juices of the stomach as closely as possible to try to emulate physiologic conditions? Who or what rule prohibits you from using hydrochloric acid, and what are you trying to determine by the experiment?

You could try the experiment using pure water. If you want an acid environment, but cant’t use hydrochloric acid, you might consider vinegar (i.e. acetic acid). Acetic acid is sometimes used in chemistry experiments because of an old chemistry rule of thumb: All acetate salts are soluble in water. Vinegar can be purchased in any grocery store(distilled vinegar is purer), and is fairly safe, inexpensive, and can legally be disposed of by dumping down any drain, though in my area you are not supposed to dump pain releivers down the drain, as unused drugs so disposed of end up contaminating our water supply and rivers.

Again, why can’t you use hydrochloric acid? If it is that you do not think you can buy it, then look in the grocery store or any place pool maintenance supplies are sold, as it is used and sold for this purpose. It is sometimes called muriatic acid. If you use gloves and face/eye protection and good ventilation when handling it, it is fairly safe to use, particularly in dilute form.

So, in summary, what you should use depends on what you are trying to test, and what and why constraints are being placed on you. Talk to your chemistry/science teacher for more practical advice based on your local situation.

Best wishes for a great project!

Barrett Tomlinson

[donnahardy2]

Hi Gill94,

If the problem is availability of the HCl, you can purchase muriatic acid at swimming pool supply stores. Stomach acid is pH 1, or 0.1 M HCl, so you would need to dilute the concentrated acid in water. You definitely need to use safety precautions (eye protection) when working with acid, but I agree with Barrett that there should be no reason not to use this for your experiment.

Donna Hardy

[Gill94]

the only reason im not using hydrochloric acid is because it needs to be used with extreme caution and it is highly corrosive and has a very strong smell, so it wont be good using it indoors so i think something like vinegar would be mch safer.

Thanks for the help!

[donnahardy2]

Hi Gil,

Concentrated HCl is 12 M, and this acid is definitely corrosive and you wouldn’t want to work with it at home. Stomach acid is 0.1 M, equivalent to a 1: 120 dilution of the concentrated acid in water, so is much safer to work with. You would want to wear safety glasses, gloves, and old clothes when working with it. However 0.1 M HCl would be much better for your experiment. Vinegar usually has a pH of about 2.5 and acetic acid has different solvent properties than HCl.

Donna Hardy