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Offline ilox

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hydrochloric acid
« on: 30/09/2005 04:24:35 »
Hello is there any way of making extremely concentrated Hydrochloric acid from electrolysis of water with sodium chloride, collecting the chlorine and hydrogen and mixing it with water?


 

Offline rosy

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Re: hydrochloric acid
« Reply #1 on: 30/09/2005 09:25:41 »
Er, I think if you electrolysed concentrated brine solution you'd get a mixture of hydrogen and chlorine which you could then react together (I think you'd have to spark it or something to initiate a reation), away from the solution you'd electrolysed them out of (or they'd dissolve straight back in and you'd be back where you started).
You'd have to collect quite a lot of gas to make any quantity of acid, and then you'd have to react it in the presence of a small amount of water.
I don't think any of this would be a good idea because chlorine is nasty stuff and HCl is also thoroughly unpleasant, the solution is one thing, but the gas will dissolve in any water that's handy...
 

Offline ilox

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Re: hydrochloric acid
« Reply #2 on: 01/10/2005 02:59:04 »
is there any way to concentrate store bought stuff?
 

Offline itsjustme

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Re: hydrochloric acid
« Reply #3 on: 02/10/2005 11:45:37 »
not HCl because its boiling point is below H2O's boiling point, but you can concentrate H2SO4 wich you get from used car batteries, heat it until white fumes appear, lower the flame until they dissappear but water still escapes, do this until all water is gone. Extremely concentrated H2SO4 is almost as thick as motor oil.
« Last Edit: 02/10/2005 11:50:51 by itsjustme »
 

Offline itsjustme

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Re: hydrochloric acid
« Reply #4 on: 02/10/2005 11:47:14 »
HEY!! i just thought of it... heat the HCl on a low flame so the water does not boil and distillate it.
« Last Edit: 02/10/2005 11:48:45 by itsjustme »
 

Offline rosy

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Re: hydrochloric acid
« Reply #5 on: 02/10/2005 12:25:36 »
But only if you've got equipment that can take the fumes... wouldn't want to do this myself.

If you do make concentrated acid bear in mind that it will react violently with water (the water gets so hot when added to conc acid it will boil, spitting conc acid in all directions and burning any skin in the way).
 

Offline Ylide

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Re: hydrochloric acid
« Reply #6 on: 02/10/2005 12:35:41 »
13M is about as concentrated as you can get HCl...in fact if you buy "Concentrated HCl" from a chemical vendor, that's exactly what you will get.

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Offline Simmer

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Re: hydrochloric acid
« Reply #7 on: 02/10/2005 17:35:32 »
quote:
Originally posted by itsjustme

... heat the HCl on a low flame so the water does not boil and distillate it.



HCl is a gas at room temperature (down to about -85 C in fact) so you can't recondense it conventionally but you could bubble the gaseous product through water.  You can also make hydrogen chloride gas by heating sodium chloride in concentrated sulphuric acid.

As many of the posters above have pointed out, this is dangerous stuff, both the gas and the solution are toxic and very corrosive. IMO it'd be very risky to try it without the proper glassware, a laboratory fume cupboard and all the PPE you can wear without falling over :)
 

Offline Simmer

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Re: hydrochloric acid
« Reply #8 on: 02/10/2005 17:50:42 »
quote:
Originally posted by Simmer
[br  You can also make hydrogen chloride gas by heating sodium chloride in concentrated sulphuric acid.



PS  If you do it this way and bubble the gas into water make sure the water can't be sucked back into the sulphuric acid when the heat is removed!  Otherwise KERPOW! Hot concentrated sulphuric acid and broken glass everywhere [xx(]

A good way to do this is to have an expansion chamber in the gas line, large enough to hold all of the water and then some, held vertically so that the gas from the sulphuric acid vessel comes in at the top and connects to the bubbler in the water at the bottom.
 

Offline ron.rooney

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Re: hydrochloric acid
« Reply #9 on: 01/11/2005 05:37:33 »
quote:
Originally posted by ilox

is there any way to concentrate store bought stuff?


You can only concentrate HCl from dilute HCL up to about 50% of the concentrated acid (which is itself about 35% HCl).  It forms a constant boiling mixture, so that if you boil more dilute acid you lose water until the constant boiling mixture is obtained, or if you boil concentrated acid you lose HCl gas until the same level is reached.
 

Offline Simmer

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Re: hydrochloric acid
« Reply #10 on: 01/11/2005 22:20:15 »
Interesting, thanks Ron!  Maybe you could freeze off the water instead?
 

Offline Equalizzer

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Re: hydrochloric acid
« Reply #11 on: 13/11/2005 19:19:19 »
oooo interesting

I Know A Good Experiment:
mix, H2O and H2O and you get well just H2O. :)
 

Offline robotjesusbeta

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Re: hydrochloric acid
« Reply #12 on: 16/11/2005 20:34:32 »
the concentration method of boiling H2so4 is sketchy, I cant find much info on it with reguards to what Fumes are given off when its heated, but that again would depend on what the H2s04 was like if it was a nice solution of water then you could simply regulate the heat on a hotplate and recondence vapour if need be. What do yawl think on this ?

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Offline ukmicky

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Re: hydrochloric acid
« Reply #13 on: 16/11/2005 23:09:12 »
Hydrochloric acid, Isnt that the stuff we have in our stomachs.

Michael                                      
 

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Re: hydrochloric acid
« Reply #13 on: 16/11/2005 23:09:12 »

 

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