Silverado7
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Hydrogen Chloride
From looking around at mainly Matt's Ammonium Chloride...etc. thread I saw that someone posted that the first stage of the mixture was hydrogen
chloride. Question: at what point do you know that that stage is over? Since Matt was capturing the gas in water, that means that at one point
hydrochloric acid was the product. Is there any sign in either the gas production of the powder mixture or the activity in the water that signifies
the end of that first stage? any physical properties of the gas? Anything?
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kclo4
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There are ways, but If you want the Hydrogen Chloride, and not the Ammonia you could simply mix NaHSO4 and NaCl.
This should be of Interest to you: http://www.erowid.org/archive/rhodium/chemistry/hclgas.argox...
If you were planning on also getting Ammonia from the mixture afterwords, I would recommend a different way to make NH3 gas. decomposition of Urea, or
the react of Urea on Sodium hydroxide or a Carbonate will produce Sodium Cyanate (NaOCN) and NH4OH, or (NH4)2CO3 which will decompose when they form
to let off NH3, H2O, and if the carbonate is used, also CO2 - which might get in the way of some reactions.
This reaction can get a bit out of hand, I've had Ammonia "blown" in my face from this reaction, not all that fun!
Something I just though of to produce an Ammonia solution would be to react Calcium Oxide or Hydroxide with an Ammonium sulfate solution. The Calcium
Sulfate that formed would precipitate (most of it, I believe.. a small amount of it will be left in the solution, and it may form a complex, or have
increased solubility with the Ammonia present.)
The reason I would recommend a different way is being it would be hard to heat the reaction mixture evenly. For instance, if you had a test tube full
of the NaHSO4 + NH4Cl mixture, the bottom would start producing the HCl first, and once the entire reaction was producing HCl, the bottom would get
hot enough to produce NH3, which would react with the form HCl above.. which would essentially just but NH4Cl into the air. - it would work, but it
wouldn't be very high yield or practical at all, and have a lot more of impurities then other methods.
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Silverado7
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The only reason I am proposing this idea is because I am in pocession of sodium hydrogen sulfate, but not sodium chloride. Wait a minute... if I heat
sodium hydrogen sulfate with a salt from the kitchen, would the hydrogen chloride's composition remain the same as if I did it with pure sodium
chloride? Hmmmmmm... probably not. But I thought it was you who said that when heating ammonium chloride and sodium hydrogen sulfate, the first
reaction would be the release of hydrogen chloride. My question was if there is any way to tell when that stage ends. If there is, I'd like to know
it.
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kclo4
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Table salt is pretty pure NaCl and it would work. HCl is a nasty nasty gas.
Yes It was me I think. But like I said, it would be hard to heat the entire reaction evenly with out it getting to hotter in one area then another
causing it to be producing both NH3 and HCl at the same time. If it were a small reaction (only a few grams) the localized heating probably wouldn't
be that big of a deal.
The HCl reaction can happen in water, so if you don't want anhydrous HCl you could mix NH4Cl and NaHSO4 in an amount of water and heat this will cause
it to let off HCl. Once that is done, and the water is gone, you can then heat it to decompose the Ammonium Sulfate that formed to make Ammonium
Bisulfate and Ammonia.
I'm not sure if you can tell when the reaction is done by simply heating the two salts together. Perhaps its melting point, or simply by the smell of
what is coming off of it.
But like I said, with NH4Cl your going to have sublimation problems making this very impractical even though the reaction will occur.
If I remember correctly, I have distilled nitric acid from a very concentrated solution of Sodium Bisulfate and Potassium or Ammonium Nitrate. I don't
know the percentage of the acid, but I remember it was decently concentrated.
NaHSO4 when hot can be a fairly strong acid.
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Silverado7
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I completely agree. I've done experiment with heting sodium hydrogen sulfate. It's almost impossible to capture the vapors in water with an angled rod
because the solvent shoots up through the rod and into the heating mixture. That makes a very very very very very very very strong acid. Ok, so I
guess I'll just use the purest table salt I can find in the kitchen. Thanks.
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kclo4
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Cool, let me know how it goes I guess.
Why is it you want Hydrogen Chloride anyways?
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not_important
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| Quote: | | Originally posted by Silverado7 Ok, so I guess I'll just use the purest table salt I can find in the kitchen. Thanks. |
Non-iodised salt, like koshering salt, is good, but the cheap coarse salt used for regenerating water softeners will work fine. If all you want is
the HCl, you really don't care about the metals in the chloride because they stay behind, nor is sulfate important.
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Silverado7
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To answer your question, kclo4, I am probably going to dissolve it in water, or maybe condense it to make a small supply of pure hydrochloric acid. I
need hydrochloric acid as one of the most important ingredients in a lab, as I've learned.
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