Pure HCl

[jowrose]

I've tried to create 100% hydrochloric acid a few times, but I don't seem to have succeeded. I boiled muriatic acid (~30% HCl) and put it through a home-made condenser, but the liquid I ended up with wasn't pure acid (at least I don't think so). I read somewhere that HCl is a gas at room temperature, so it must be dissolved in the water. Does this make creating pure acid impossible (without using extensive amounts of pressure)?

[jdurg]

Hydrogen chloride is a gas, so in order to liquify it you would need to compress it, or cool it down significantly. Either way, the liquified gas is incredibly corrosive so it is virtually always transported as a solution in water which is known as hydrochloric acid.

[jowrose]

ahhhh ok. Thanks. So that's probably not something I could do in my basement...

[RyanJ]

ahhhh ok. Thanks. So that's probably not something I could do in my basement...

 

If you had Hydrogen and Chlorine when you could.

 

Because its a gas at room temperature after a certain point there will be no water left and thus it wil turn back into its gas form (Corrosive) - if you could apply enough pressure to this you could make it liquid for shure

 

Like I said, I don't think you will be able to get Hydrogen and Chlorine cylinders nor would you have the ability to apply a lot of pressure to the gas so as jdurg said the answer is a big no

 

Cheers,

 

Ryan Jones

[woelen]

Making pure HCl gas is not difficult to do at all. Just add some table salt to concentrated H2SO4 and the stuff starts bubbling and foaming. Dry HCl gas is colorless and not that corrosive, but as soon as it comes in contact with air, it starts fuming increadibly, picking up moisture and forming small droplets. This fume IS corrosive. It eats metal things and accelerates rusting of iron objects a lot.

 

Pressurizing the gas, until it is a liquid, forget about that at home, unless you have some really advanced equipment.

[YT2095]

besides pure HCl(g) is practicaly useless for the home chemist anyway, you`re much better off storing it as the acid, and with care you can get pretty close to 40% conc if you store it in a cold fridge in a pressure bottle not completely filled, but you`ll find that the 30% that you already have, is more than ideal for anything you (or we) are likely to want to do with it

[woelen]

I agree with YT. I have a few liters of 30% HCl and I also have one liter of 37...38% HCl. The latter is a REAL pain on storage. It is somewhat pressurized and when I open the bottle an immensely thick and choking white fume is produced, as soon as the cap is loosened somewhat.

 

Till now I have not found a single experiment, which I could not do with my 30% HCl and which needed 37%. The only reason for me, having that 37% bottle is that it is reagent grade from a chemical supply house, while my 30% acid is technical grade from hardware stores. Some of my experiments require very pure reagents and then I use the reagent grade.

[jowrose]

I by no means have anything near advanced equipment. I don't even have a bunsen burner, just an alcohol lamp thing and a hot plate. It's all fine for what I do though so I'm not complaining.

 

Sulphuric acid is commonly found in car batteries, correct? I think I read that somewhere. Probably the anarchist cookbook, but I don't trust that thing at all. Follow that thing and you're liable to blow off your hand.

 

thanks for the replies, very helpful stuff you guys have been posting

[YT2095]

the anarchists crapbook is NOT to be trusted, you`re bang on the nail there!

 

and yes H2SO4 is found in car batteries at about 35% conc, although it`s best to charge the batteries as best as you can before taking the acid out, it`ll save you alot of work later on

[jowrose]

Do you just kinda start hacking away at a battery? Or is there a specific method? I would go out and buy chemicals but I highly doubt anyone would sell it to me... I was lucky to get muriatic acid methinks.

[woelen]

Try to find drain cleaner. Drain cleaners come in two "tastes", the alkali one and the acid one.

 

The alkali one is NaOH. This is interesting to have on its own. The acid one is 92 .. 97% H2SO4 with some organic impurities, but for many experiments it is perfectly suitable.

 

There also are some other drain cleaners with diluted acids or bases and all kinds of soap added. Avoid those. You need the real stuff. "Caustic soda" or "lye" or "sodium hydroxide" for the basic stuff.

 

Beware, however, with concentrated H2SO4 and NaOH. Both are capable of eating holes in your skin at quite a high rate. Besides that, both produce a lot of heat when diluted with water. Always add the acid (or NaOH) to water, not the other way around.

 

If you use 35% H2SO4, then you cannot make HCl as gas. The acid simply contains too much water and the gas will remain dissolved. At most your liquid may give off a little amount of fume, but that's all.

[jowrose]

do as you outta, add acid to watta

 

Yeah, lye is dangerous stuff. I read that it is used by some to create pure sodium, rather than heating up sodium chloride and running a current through it (which is a pain, i've tried). Supposedly you only need to get lye up to 600 degrees before you can start to separate it, but at that point it will eat through just about anything. So i didn't feel like trying...

 

Drain cleaners are up to 97 % H2SO4? wow, I didn't know that. I'll have to pick some up.

[jdurg]

Yeah, the Roto-Rooter brand is typically a good source of sulfuric acid. You can tell if it's a good source when it has bright red warning labels about corrosivity and other warnings.

 

NaOH is indeed a nasty little substance. When making sodium iodide from its pure elements, I had a little blob of molten sodium metal fly onto my right hand. It reacted with my skin and immediately formed a tiny speck of VERY concentrated NaOH. It didn't really hurt all too much right away, but it quickly made a very deep pin-hole in my hand which grew pretty sore over the next few days. I had what probably amounted to a mere nanoliter of liquid sodium on my hand, but it left a pretty significant mark which still shows up today.

[jowrose]

Ouch. I was melting pennies with thermite once, and the zinc inside some of the new pennies melted really quick (actually i think it might have boiled) and the penny blew up and spewed molten metal everywhere. that was pretty scary.

 

Yeah, just look for the biggest and gaudiest warning labels and you're probably getting some fun stuff...

[YT2095]

Do you just kinda start hacking away at a battery? Or is there a specific method?

 

Oh good greif, certainly NOT!

you simply charge the battery as best you can, and then you open the topup vents with a simple screwdriver as if you were going to add the distilled water to it.

except you invert the battery over a plastic bowl and pour the liquid out into it.

from there you put a funnel into a bottle and pour the bowl contents into that and store it SAFELY and MARKED UP clearly as Acid.

 

there really is no need to "hack away" at the thing, unless you really Hate that particular battery:rolleyes:

[jowrose]

I think I'll just purchase some drain-cleaner... Easier, plus you get better concentration.

[Pleiades]

Roto-Rooter is indeed a good source of sulfuric acid; it is easily recognizable as a white bottle with red writing, packaged in its own sealed plastic bag.

 

If you could get a hold of a cylinder of chlorine and a cylinder of hydrogen (which is pretty unlikely), you could probably buy several regulators to lower the pressure to just above atmospheric, then mix the two in some tubing that is highly acid resistant, plastic or something maybe. You would have to make sure the two mixed in the correct ratio, probably by adjusting the flow.

 

Of course, the 100% pure HCl produced would be highly dangerous, and would have to be contained in some sort of reaction vessel until it reacted to produce something less dangerous. Allowing 100% HCl to escape into the air would be very bad as it attacks everything. I left a bottle of 28% aqueous HCl on a countertop for a few days and it left a bleached ring in my expensive granite countertop. The liquid on the threads of the sealed bottle was probably the culprit. I can only imagine the horror of allowing 100% gaseous HCl to contact skin. *shudders*

[jdurg]

Mixing hydrogen and chlorine gases to make HCl is an INCREDIBLY foolish thing to do. H2 and Cl2 don't passively combine to form HCl. They explosively combine akin to hydrogen and oxygen. Industrially, HCl gas is produced by the action of sulfuric acid on NaCl and NOT by the combustion of hydrogen in a chlorine atmosphere. Making HCl from its constituent gases is about as productive as making water from its constituent gases.

[raivo]

HCl can be made by mixing H2 and Cl2 but as jdurg sayd these will not react but may explode even if intense light falls suddenly onto the mixture. H2 and Cl2 can be safely reacted if reaction vessel is small and contains sparkgap that ignites mix of gases as soon as there is anything to ignite. To make HCl from H2 and Cl2 is not practical because in real world chlorine tends to be more expensive than HCl. I make mine by recting HCl with KMnO4.

[Pleiades]

I never said it would be a good idea, but I didn’t do enough research to see that it’s a highly exothermic combustion reaction. I don’t know what material would stand up to high temperature, high pressure, corrosive HCl, but if you could find one, I don’t see why you couldn’t make 100% HCl at home, wouldn’t catch me doing it though, as you said, it would be incredibly foolish.

 

So to answer your question jowrose: Making 100% HCl isn’t impossible, it’s just highly dangerous, expensive, impractical, and just about useless to the amateur chemist.

[jdurg]

You can make anhydrous HCl, however, by added concentrated H2SO4 dropwise to a pile of NaCl. HCl gas will evolve from the salt. This is how it's done industrially. (Though they have very large piles of salt and very large 'drops' of anhydrous sulfuric acid).

[jowrose]

yeah, I don't think I'll be trying it anytime soon... just using the acid will be fine. My parents probably wouldn't appreciate the explosions in hte basement. Just as they had little appreciation for the 250 grams of sugar-potassium nitrate mixture that ignited prematurely...

[Pleiades]

Haha, speaking of explosions reminds me of the time I prepared some ammonium tri-iodide: I had spooned the wet crystals onto pads of folded up tissue paper and then folded up the pads and tied them off into little bags. Well, I left about 12 of these little bags to dry out on the porch, and something set them off, and being shock sensitive, the whole lot went off in a chain explosion, my mother told me it sounded like a machine gun. I learned my lesson there. I thought it was pretty funny, but my mother wasn’t so impressed, I was just glad to see I had made it right.

[jowrose]

hahaha that's awesome. How do you make that stuff? sounds fun.

[woelen]

Haha, speaking of explosions reminds me of the time I prepared some ammonium tri-iodide: I had spooned the wet crystals onto pads of folded up tissue paper and then folded up the pads and tied them off into little bags. Well, I left about 12 of these little bags to dry out on the porch, and something set them off, and being shock sensitive, the whole lot went off in a chain explosion, my mother told me it sounded like a machine gun. I learned my lesson there. I thought it was pretty funny, but my mother wasn’t so impressed, I was just glad to see I had made it right.

Don't mess around with what you call ammonium triiodide.

• First, that is NOT the name of that compound, ammonium triiodide is as explosive as a dead dog. You made a different compound.
  
• Second, please no further discussion about that XXX stuff you made. K3wls are reading this as well and we should not give them noughty and dangerous ideas. If a k3wl blows off his hands (or more), then this forum may cease to exist if it becomes clear that that info is from here.