What experiments can I do with hydrochloric acid?

I got some hydrochloric acid to clean quartz, which is talked about in another thread. I hardly needed to use any of it, so I’m wondering what interesting chemistry experiments I can do with it. I’ve already mixed it with baking soda (sodium carbonate). I can’t think of any other household ingredients that would have an interesting reaction. I don’t want to do anything explosive by the way. And yes, I know to handle hydrochloric acid with care and all that.

IIRC from 8th grade chem, metal nails will rust in it.

I wonder what would happen to snails?

Or puppy-dog tails!

Do you have any limestone around the yard? The kind with those little quartz inclusions can get pretty interesting after a few days soak in HCl.

What would that produce? Ferrous chlorite? I could probably find some big chunks of rust to do this with.

And no, I don’t know of any limestone around here.

Well, if you figure out the right proportions, mixing it with lye (sodium hydroxide) will produce salt. Right?

NaOH + HCl --> NaCl + H20

Get a penny that was made after about 1982 (when they switched from solid copper to copper-clad zinc). Make a scratch in it with a knife, so that a little bit of the zinc is exposed, and soak it in acid. You’ll see bubbles of hydrogen gas forming along the scratch because copper is inert to hydrochloric acid, but zinc reacts with it to form hydrogen. If you let it soak long enough, all the zinc will dissolve and you’ll end up with a thin copper shell.

The hydrochloric acid and baking soda (sodium bicarbonate) produced salt.

HCl + NaHCO3 -> NaCl + H2O + CO2

It was cool mixing the two, sticking the tip of my finger in it, and licking it and tasting saltwater even though I knew ahead of time what was going to happen.

I was interested in something that would precipitate though so I could see it. I checked my chemistry book though and the only cations that will mix with chlorine and precipitate are silver, mercury, and lead, none of which are really easy to come by. You can’t exactly go to the hardware store and buy silver nitrate or plumbus acetate (or can you?).

So I figured maybe I could get a metal that would dissolve in hydrochloric acid but dissolve if I put in some sulfuric acid. The best metal for that would be calcium though, and I can’t think of a common compound with calcium. Maybe there just aren’t as many interesting things to do with hydrochloric acid as I figured there would be.

Interesting. I already put three pennies in it not realizing copper wouldn’t dissolve. One of the pennies did bubble for a while, so maybe it did just that. I’ll go check it soon.

Go down to the local pond and net a few frogs…stick them in your handy dandy beaker and pour some… :eek: :smack:

Sorry, I’m not a sadistic little boy anymore.

[sup]Sorry, I’m not a sadistic little boy anymore.
Sorry, I’m not a sadistic little boy anymore.
Sorry, I’m not a sadistic little boy anymore.
Sorry, I’m not a sadistic little boy anymore.
Sorry, I’m not a sadistic little boy anymore.
Sorry, I’m not a sadistic little boy anymore.
Sorry, I’m not a sadistic little boy anymore.

Tums, for instance, are calcium bicarbonate. Mylanta is a mixture of magnesium bicarbonate and aluminum bicarbonate.


Ca(HCO3)2+2HCl -> CaCl2(aq) + 2CO2 + 2H2O
Mg(HCO3)2+2HCl -> MgCl2(aq) + 2CO2 + 2H2O
Al(HCO3)3+3HCl -> AlCl3(aq) + 3CO2 + 3H2O

Pretty boring, overall.

Y’know, this got me thinking…

I’m pretty sure plain-old solid aluminum will react with HCl (read that someplace in relation to an instrument I was using), while, as mentioned above, copper will not.

Now, if aluminum does react…

Al + 3HCl -> AlCl3(aq) + 3/2H2(g)

Sooooo, being very careful about controlling heat (I bet this is exothermic in a way that might require considerable caution), you could shred a beer can and perform the reaction in a bottle with a balloon on top of it, and make your own little Hindeburg.

Just like the Hindenburg, it will, however, go up in a ball of flames if you allow it to come into contact with something that will ignite it. So, uhhh, don’t do that.

Don’t know about HCl specifically, but aluminum tends not to react with acids in general.

Lye WILL react with aluminum to form hydrogen, however, and condoms work better than balloons. (lighter, stretch much more before popping). A lit cigarette makes a nice fuse for such prophalctic hindenbergs.

That’s just because it has a tough coating of aluminum oxide, sapphire, on its surface. If you scratch that off, aluminum is very reactive.

***What Experiments Can I Do With Hydrochloric Acid?

That thread title seems like one of the items that makes my annual “Dangerous Christmas Toy” list here on the Straight Dope.

Okay, since I hijacked your thread a bit there, I remember a LONG time ago, I saw Mr Wizard (long before he was on Nickelodeon).
He did an experiment whereby he poured acid into a jar of sugar. It made a huge plume of ash but solid enough whereby he could grab it with a pair of tongs. I think he used Sulfuric acid though. Maybe Hydrochloric acid would have a similar reaction?
CAUTION: I’d be VERY careful about doing this. Among other things, I’m sure huge amounts of heat will be produced. So, we have:

H Cl + C[sub]6[/sub] H[sub]12[/sub] 0[sub]6[/sub] -------> ???

Nope. Unlike sulfuric, nitric, or perchloric acids, hydrochloric acid is not a strong oxidizer. You’d just end up with wet sugar.

The “concentrated sulphuric acid + sugar” experiment was one of the most memorable of all of the experiments that we ever did in chemistry at school.

I like the Hindenberg idea, but it probably wouldn’t work. Even if the bottle was light enough, the water left over probably wouldn’t be.

The calcium carbonate may be somewhat interesting. It should dissolve in hydrochloric acid and then precipitate as calcium sulfate after adding sulfuric acid. I may try that.

Thanks for the information about that experiment. I had a feeling it was H[sub]2[/sub]SO[sub]4[/sub] but I was hoping snailboy would have another use for HCl. Guess not.