Experiments with Hydrochloric Acid (not really concentrated) at home

[ISamson]

Hello,
I have recently realized, that I had just made hydrochloric acid (HCl) (not really concentrated) at home by mixing NaCl with vinegar . I am interested in some experiments than I could easily conduct at home. I am interested in making ions or pure substances. Do you have any advice or suggestions?

 

[Borek]

I wouldn't say you have made hydrochloric acid. Yes, your solution contains ions present in hydrochloric acid solutions, but it doesn't mean it will behave as hydrochloric acid does.

Think about it this way: imagine mixing solutions of NaCl and KBr (sodium chloride and potassium bromide). Mixture contains four ions. No imagine mixing solutions of NaBr and KCl. You have produced identical solution (assuming you used same concentrations and volumes). You can't tell which solution is which, so technically you can't say whether the solution contains - say - sodium or potassium bromide. No, it contains separate ions, not particular compounds.

Can't think of any interesting experiments that will not require additional reagents though.

 

[ISamson]

I wouldn't say you have made hydrochloric acid. Yes, your solution contains ions present in hydrochloric acid solutions, but it doesn't mean it will behave as hydrochloric acid does.

I have conducted some research about possible outcomes of my reaction and I believe I have done this:

NaCl+CH3COOH=HCl+NaCH3COO

This is a balanced equation.
Does it not count as hydrochloric acid? Why?

 

[Borek]

Do you know what dissociation is?

 

[ISamson]

Do you know what dissociation is?

As far as I know, dissociation is when molecules break down as a result of an electric current being applied to the solution. As a result, ions that made up the substance are left. For example, when dissociation is applied to H2O, then the result is a positive ion of hydrogen and two negative ions of oxygen. Right?

Why?

 

[Borek]

Nope, that's not how it works. Dissociation in general has nothing to do with electric current. When you dissolve ionic salt (like NaCl) or an acid, especially a strong one (like HCl), or a strong base (like NaOH) they dissociate into ions and the solution contains just these ions. So for example NaCl solution is a mixture of Na⁺ and Cl^- dispersed in water (this is part of a basic chemistry syllabus).

Now, reread my earlier post about NaCl/KBr solution and see how it applies to the equation you posted. Does it really describe any reaction, when all ions present are just floating?

It may happen that some ions do precipitate out of the solution, when the salt they produce is weakly soluble. Yes, then we will talk about reaction occurring.

 

[ISamson]

Nope, that's not how it works. Dissociation in general has nothing to do with electric current. When you dissolve ionic salt (like NaCl) or an acid, especially a strong one (like HCl), or a strong base (like NaOH) they dissociate into ions and the solution contains just these ions. So for example NaCl solution is a mixture of Na⁺ and Cl^- dispersed in water (this is part of a basic chemistry syllabus).

Now, reread my earlier post about NaCl/KBr solution and see how it applies to the equation you posted. Does it really describe any reaction, when all ions present are just floating?

I see what you mean with changing the place of the ions, but when I tried to test if I had actually made HCl or not, it looked like I have. I tested this by placing dirty coins in the solution and they became clearer.
However the thing with solutions and chemical reactions is that the ions do change place in the chemicals to form other, new substances. No?

 

[Borek]

I see what you mean with changing the place of the ions, but when I tried to test if I had actually made HCl or not, it looked like I have. I tested this by placing dirty coins in the solution and they became clearer.

That's because they actually react with H⁺, not hydrochloric acid per se. (Actually in the case of copper coins combination of H⁺ and Cl^- yields some pretty interesting chemistry, but I suppose it is way over your knowledge level at the moment).

However the thing with solutions and chemical reactions is that the ions do change place in the chemicals to form other, new substances. No?

Yes, but just because some ions are present at the same time in the solution doesn't mean they will react, quite often they just float around and ignore each other.

So, the initial example with NaCl/KBr is one of those when nothing happens. The one with NaCl/CH₃COOH is another one of this type. But for example mixing solutions of AgNO₃ with solution of NaCl will produce a precipitate (so there is a reaction occurring), and mixing solution HCl with NaOH will produce H₂O (technically Na⁺ and Cl^- present in the solution don't react, as they don't change at all, they are called spectators; but if you dry the solution out you will get NaCl crystals).

Google for net ionic reactions, that's how this concept is called.

 

[ISamson]

I think I actually know quite a lot in physics and chemistry for my age...
Thanks for all your advice and information Borek!

 

[Borek]

I think I actually know quite a lot in physics and chemistry for my age...

I am 54 and I guess I can say the same about myself

But, with each thing I learn I am more and more aware of how many things I actually don't know.

 

[ISamson]

But, with each thing I learn I am more and more aware of how many things I actually don't know.

Absolutely true! Same here. It is just unimaginable how much information humanity has accumulated over these millenia.

 

[stefan r]

Vinegar could do a lot of cleaning on a penny by itself. Vinegar is recommended as a non-toxic cleaner for kitchens. HCl should damage (or clean/remove) tile grout or concrete and will leave stains on stainless steel.

 

[Borek]

Vinegar could do a lot of cleaning on a penny by itself.

Yes, trick is, presence of chlorides makes reactions much easier (most likely through Cu(I)Cl path).