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amateurawesomeness
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Concentration of HCl
This is my first post. Yay.
I have 200ml of 0.1M Hydrochloric acid. This is ridiculously dilute and is not very useful in experiments. I want to concentrate it to 1M without
losing too much of the solution, but I am unsure about how to do this(I'm new to chemistry).
I know it will have to be done by distillation or evaporation but I am worried that I will lose most of it.
Any ideas?
Thanks
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AJKOER
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Add NaCl and some FeCl3 (very important). Distill.
The addition of these salts is reputedly reported to may it possible to concentrate, upon distillation, almost any dilute HCl.
See if works.
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amateurawesomeness
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Thanks for the quick reply.
I will try in a few days and see if it works. any idea how much of the salts I should add? I don't wanna mess it up.
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Pyro
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If he's new to chem he probably doesn't have a distilling apparatus.
I don't know if this will work if its so dilute. but heating it should drive the HCl out of solution, so heat it in a small container with a hose
leading the gas into ice cold water. otherwise you could either make it from drain cleaner H2SO4 and table salt or just buy it in the hardware store,
its usually very cheap and quite pure depending on the brand.
all above information is intellectual property of Pyro.  |
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amateurawesomeness
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I have homemade distillation stuff (old tubes and stoppers mostly). I will try these methods and if they don't work I'll give up and buy some.
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Hexavalent
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Quite frankly, I don't think a beginner to chemistry should be handling concentrated sulfuric acid...
Supposedly just distilling dilute hydrochloric acid will induce the azeotrope, which is a 20 %w/v (?) solution of HCl in water. However, as
aforementioned, as your starting acid is so dilute, I'm not sure this will work.
Finally, I'd be cautious about using rubber stoppers when distilling acids...nitric acid destroys rubber stoppers, but I'm not certain about
hydrochloric.
[Edited on 14-4-2013 by Hexavalent]
"Success is going from failure to failure without loss of enthusiasm." Winston Churchill
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plante1999
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Don't listen to him! Better to wait until something decent come out! (refering to AJKOER)
You should consider buying sodium bisuphate, it is available as pH down for pool. Reacting this with sodium chloride will make HCl gas that can be
dissolved in water.
[Edited on 14-4-2013 by plante1999]
I never asked for this.
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amateurawesomeness
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Thanks plante1999. I have some sodium bisulphate crystals and a bottle of a solution of it so that should be really useful. I'll probably just pour
the whole bottle in (about 90ml) I just saw a nurdrage video explaining it and it looks quite simple. The funny thing is, I'm not sure I have any
sodium chloride. 
[Edited on 14-4-2013 by amateurawesomeness]
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Hexavalent
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No, don't use the solution. AFAIK, using the solid sodium bisulfate is more efficient, although you may need some water depending on your heat source,
as NurdRage explains.
"Success is going from failure to failure without loss of enthusiasm." Winston Churchill
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plante1999
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Sodium chloride is sold as Salt in the majority of grocery stores, for about 2$ per Kg.
I never asked for this.
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Pyro
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If he's new to chem he probably doesn't have a distilling apparatus.
I don't know if this will work if its so dilute. but heating it should drive the HCl out of solution, so heat it in a small container with a hose
leading the gas into ice cold water. otherwise you could either make it from drain cleaner H2SO4 and table salt or just buy it in the hardware store,
its usually very cheap and quite pure depending on the brand.
all above information is intellectual property of Pyro. |
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BlackDragon2712
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what about electrolisis of NaCl? you can react the chlorine with water to make HCl, just put a carbon anode and cathode and pass electricity to them
while they are submerged into a satured solution of table salt. you put a hose in the chamber and you put the other part in ice cold water and you
have HCl, is the easyest way to do it. concentrating HCl is difficult because is a gas diluted in water, considering this remember that gases are less
soluble at higher temperatures, and your solution is so diluted that you must remove 99% of the water in order to reach a concentration close to 10M
and 96% of the water for a solution of 10% HCl
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elementcollector1
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Quote: Originally posted by BlackDragon2712  | | what about electrolisis of NaCl? you can react the chlorine with water to make HCl, just put a carbon anode and cathode and pass electricity to them
while they are submerged into a satured solution of table salt. you put a hose in the chamber and you put the other part in ice cold water and you
have HCl, is the easyest way to do it. concentrating HCl is difficult because is a gas diluted in water, considering this remember that gases are less
soluble at higher temperatures, and your solution is so diluted that you must remove 99% of the water in order to reach a concentration close to 10M
and 96% of the water for a solution of 10% HCl |
The Cl2 would disproportionate in the water to form HCl and HOCl. A better method would be to react the H2 and Cl2 in presence of UV light (in a
non-glass container) to form 2HCl, and then pass that through a small amount of cold water. Unfortunately, this reaction's rather explosive.
Elements Collected:52/87
Latest Acquired: Cl
Next in Line: Nd
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AJKOER
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This statement has a few issues:
"A better method would be to react the H2 and Cl2 in presence of UV light (in a non-glass container) to form 2HCl, and then pass that through a small
amount of cold water. Unfortunately, this reaction's rather explosive"
First, uv light will not penetrate anything other than a clear very thin container. I know this because only then will uv rays detonate a pure H2 and
Cl2 mix. By pure, I mean no O2, which apparently poisons, even in small amounts, the chain reaction leading to an explosion. Next, to say it is
explosive is a big understatement. The kinetics are so high that this reaction has been suggested as possible replacement of Gasoline/O2 engines and
is more powerful than H2/O2 (there are videos of H2 and Cl2 explosions on the web). No way anyone could capture the HCl, you will just lose some body
parts is the more likely scenario.
Further, adding Cl2 to water to make HCl and HOCl is not that good either as chlorine is not that readily soluble in water (perhaps adding a little
SO2 might help).
----------------------------------------------------
On the NaHSO4/NaCl solid reaction, why bother? The NaHSO4 is a more friendly (and weaker) substitute for H2SO4 in many reactions. If you readily need
HCl in an experiment, make it in situ by adding NaCl to a hot concentrated NaHSO4 solution. Not only is this safer, but with excess NaCl, the
concentrated ionic solution may actually have an 'activity level' for your HCl in excess of what you could make from the same amount of NaHSO4 by
dissolving the hydrogen chloride gas in water.
[Edited on 14-4-2013 by AJKOER]
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Erbium_Iodine_Carbon
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You can put your HCl in the freezer and the water will freeze out leaving you with more concentrated acid. Keep straining out the ice chunks until the
liquid volume is 1/10 of the original volume if you want 1 mol/L HCl.
I don't think you will have too many problems with freezing point depression because a 10% or 2.87 molar solution freezes at -18 degrees C. I found
all this information on the Wikipedia page for hydrochloric acid.
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kristofvagyok
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| Quote: Originally posted by Erbium_Iodine_Carbon | | You can put your HCl in the freezer and the water will freeze out leaving you with more concentrated acid. Keep straining out the ice chunks until the
liquid volume is 1/10 of the original volume if you want 1 mol/L HCl. |
Do you have any reference for this? Or
have anyone done this successfully?
I have a blog where I post my pictures from my work: http://labphoto.tumblr.com/
-Pictures from chemistry, check it out(:
"You can’t become a chemist and expect to live forever." |
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amateurawesomeness
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I would like to try and do the freeing method but I would only end up with 20ml of HCl.
I know where to get sodium chloride, but my family have some super strong sea salt stuff so I need to get some table salt(I used it all up).
And I need some more sodium bisulphate. I realised I only have a couple of grams. Luckily I found it cheap on the web so I'll buy some soon.
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woelen
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Another option of concentrating 0.1 M HCl is simply boiling down. You will not drive off HCl-gas at such low concentrations, due to the azeotropic
nature of the HCl/H2O mix. First you'll drive off mainly water and when the concentration comes close to the azeotropic value, there will be more and
more HCl in the vapor, but the relative amount will never be more than the azeotropic percentage. A 0.1 M solution easily can be boiled down to 1 M
without any noticeable loss of HCl.
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amateurawesomeness
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Thanks. I'll try that and if it doesn't work, then I'll go with the sodium bisulphate option.
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Fantasma4500
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i have been wondering about concentrating HCl some times myself tho i can get 30% HCl like if it was nothing..
if you cant find highly concentrated sulfuric acid you should go to a car store, or well a store where they sell things for cars and such
they usually have sulfuric acid standing around marked as ''battery acid''
its usually around 37% AFAIK, about 1.27 molarity or something
sulfuric acid can easily be boiled down to high concentration, the problem first starts when you get to 70% where SO3 starts forming, you dont want to
breath this in also its pretty well etching
just thought about another thing...
if you can get hold of a shitload calcium chloride, its sometimes used as dessicant for drying rooms etc.
CaCl2 shouldnt decompose upon heating within 1000*C or well just past 100*C.. if you dump anhydrous calcium chloride into the HCl it should suck up
the water in the solution and you can then distill the HCl
procedure can be repeated
probably possible with CuSO4 anhydrate or calcium sulfate if it doesnt make sulfuric acid and calcium chloride..
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Erbium_Iodine_Carbon
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| Quote: | | Do you have any reference for this? Or have anyone done this successfully? |
Solid-Liquid phase diagram for HCl:
http://en.wikipedia.org/wiki/File:Phase_diagram_HCl_H2O_s_l.PNG
Sources, as quoted on page:
"erstellt aus Daten vom Gmelins Handbuch der anorganischen Chemie
plotted with data from the German books Gmelins Handbuch der Anorganischen Chemie, Systemnummer 6 Chlor, Verlag Chemie Berlin 1927 and Gmelins
Handbuch der Anorganischen Chemie, Systemnummer 6 Chlor, Ergänzungsband Teil B - Lieferung 1, Verlag Chemie Weinheim 1968. Since 1990 the Gmelin was
published as Gmelin Handbook of Inorganic and Organometallic Chemistry"
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Morgan
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| Quote: Originally posted by AJKOER | This statement has a few issues:
"A better method would be to react the H2 and Cl2 in presence of UV light (in a non-glass container) to form 2HCl, and then pass that through a small
amount of cold water. Unfortunately, this reaction's rather explosive"
First, uv light will not penetrate anything other than a clear very thin container. I know this because only then will uv rays detonate a pure H2 and
Cl2 mix. By pure, I mean no O2, which apparently poisons, even in small amounts, the chain reaction leading to an explosion. Next, to say it is
explosive is a big understatement. The kinetics are so high that this reaction has been suggested as possible replacement of Gasoline/O2 engines and
is more powerful than H2/O2 (there are videos of H2 and Cl2 explosions on the web). No way anyone could capture the HCl, you will just lose some body
parts is the more likely scenario.
Further, adding Cl2 to water to make HCl and HOCl is not that good either as chlorine is not that readily soluble in water (perhaps adding a little
SO2 might help).
----------------------------------------------------
On the NaHSO4/NaCl solid reaction, why bother? The NaHSO4 is a more friendly (and weaker) substitute for H2SO4 in many reactions. If you readily need
HCl in an experiment, make it in situ by adding NaCl to a hot concentrated NaHSO4 solution. Not only is this safer, but with excess NaCl, the
concentrated ionic solution may actually have an 'activity level' for your HCl in excess of what you could make from the same amount of NaHSO4 by
dissolving the hydrogen chloride gas in water.
[Edited on 14-4-2013 by AJKOER] |
Slight tangent on the main topic ...
I was wondering if you had any more info on the oxygen posioning of the H2/Cl2 reaction.
"Vacuum UV is so-named because it is absorbed strongly by air, and is therefore used in a vacuum. In the long-wave limit of this region, roughly 150
– 200 nm, the principal absorber is the oxygen in air. Work in this region can be performed in an oxygen-free atmosphere (commonly pure nitrogen),
avoiding the need for a vacuum chamber."
https://en.wikipedia.org/wiki/Ultraviolet
I remember that H2/Cl2 demo on youtube where the fellow fires off a test tube using little LED lights. Blue sometimes works, the ultraviolet producing
the bang. Also a quartz test tube was employed to allow the UV.
http://www.youtube.com/watch?v=NN82GoBG98s
"Ordinary glass is partially transparent to UVA but is opaque to shorter wavelengths, whereas silica or quartz glass, depending on quality, can be
transparent even to vacuum UV wavelengths. Ordinary window glass passes about 90% of the light above 350 nm, but blocks over 90% of the light below
300 nm."
https://en.wikipedia.org/wiki/Ultraviolet
So I came across this title but you can't read the entire article.
"The Photosensitized Explosion of Hydrogen and Oxygen by Chlorine." I don't know if it's pertinent or not but it seemed curious.
http://www.jstor.org/discover/10.2307/95863?uid=3739600&...
I wonder though if the UV might work to initiate H2/Cl2 by creating a tiny electrostatic charge? Would water vapor/humidity have any inhibiting effect
on the hydrogen/chlorine sensitivity to detonation using UV initiation?
"On the Moon, there is no rubbing. The dust is electrostatically charged by the Sun in two different ways: by sunlight itself and by charged particles
flowing out from the Sun (the solar wind)."
http://science.nasa.gov/science-news/science-at-nasa/2005/30...
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amateurawesomeness
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So many options!
I had not heard about calcium chloride being used like that before. It looks like it would work but I don't have enough calcium chloride. I might just
go with the heating option and if that doesn't work then I'll make some from sodium bisulphate and salt.
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AJKOER
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| Quote: Originally posted by woelen | | Another option of concentrating 0.1 M HCl is simply boiling down. You will not drive off HCl-gas at such low concentrations, due to the azeotropic
nature of the HCl/H2O mix. First you'll drive off mainly water and when the concentration comes close to the azeotropic value, there will be more and
more HCl in the vapor, but the relative amount will never be more than the azeotropic percentage. A 0.1 M solution easily can be boiled down to 1 M
without any noticeable loss of HCl. |
Actually, believe it or not, adding the NaCl/FeCl3 salts as I recommended, and distilling is claimed not to be limited to azeotropic concentration.
Look it up.
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woelen
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I think that adding NaCl + FeCl3 to such a dilute solution is just spoiling things. If this is done, then ALL of the HCl must be distilled over into
another liquid. If you just boil down the liquid then no HCl needs to be distilled over into another liquid.
Maybe the NaCl/FeCl3 method works with moderately concentrated HCl, but here we are talking about 0.1 M HCl.
Personally I would go for NaCl + NaHSO4 and lead the HCl-fumes from the heated mix through distilled water. The 0.1 M HCl is so dilute that it hardly
is worth the effort and energy to gain back the HCl.
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