solarflare99
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Is this true about chloroform and amonia?
I heard a rumor that mixing chloroform and amonia will result in hydrogen cyanide, and the reason why I make this post is to confirm or deny the
validity of that assumption. I do not intend to try this myself at the moment, as it's probably extremely dangerous if true.
Is it true that if you accidently or intentionally and simply mix the liquids of chloroform and ammonia at room temperature, deadly hydrogen-cyanide
fumes will be emitted?
Or, will the mixture itself combine to form liquid hydrogen cyanide?
Or, is it safe to mix the two chemicals and the two ingredients will simply "sit together", but not mix?
[Edited on 29-6-2004 by solarflare99]
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unionised
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No, It isn't true.
There are plenty of old procedures for extracting alkaloids that rely on making the mixture basic with ammonia and extracting into chloroform.
You might be able to get HCN if you flash heated the vapours together at about 1000C or , then again, you might not; who cares?
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Organikum
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Polverone wrote here:
http://www.sciencemadness.org/talk/viewthread.php?fid=2&...
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The "easiest thing ever" that I have found, from my good friend the Hive, is that when certain chlorine-containing solvents are gently
heated and stirred for a long time with a mixture of aqueous ammonia and sodium (or potassium) hydroxide, they will form NaCl or KCl and NaCN or KCN
(look it up for balanced equations and specific directions.) Sadly, this leaves you with a mixture of salts, and I am obsessed with purity. If I were
to prepare large quantities perhaps I could separate the salts by recrystallization, but that sounds hazardous (because of larger quantities.)
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So in the presence of an alkali-metal hydroxyde and with lots of time there will be cyanide formed.
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Nick F
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Or, as unionised said, you can pass a mixture of the gases through a hot tube. I think it was around 500*C. A quick search should find the patent...
Hexamine vapours also make HCN when heated enough, along with methane I assume.
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Organikum
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Do you have some details on the hexamine to HCN Nick? Temperature etc.?
regards
ORG
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Nick F
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Originally posted by rikkitikkitavi at E&W:
"hexamine (hexamethylentetramin, (CH2)6N4) ) decomposes above 200 C to ammonia and a resninous oil. Inreasing the temperature to 330 C
HCN, CH4, N2, H2 are the basically products.
At 800 C major decomposition product is HCN!
This is utilized in a patent(country germany ?) by Plischke and Zettl for producing HCN in 90 % yield from hexamine.
First vapourizing hexamine at 260 C then heating the vapours in a ceramic oven to 800-1200 C yielding HCN.
Unfortunately this is all I could dig out from my 40 cm pile of papers regarding chemicals... ,I can produce a reference to the patent but I be gone
for R&R for a week from now."
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Organikum
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Thanks Nick!
I found it:
DE1076104
A short translation of the procedure:
Hexamine in a closed retort is heated to about 260°C (160-270°C) at which it sublimes. The vapours are vented into a tube furnace (1) which is
insides coated with ceramics and heated to 1150°C (800-1200°C) wher they are pyrolysed. The vapours have to be vented directly into the hot zone of
the furnace and cooled rapidly after leaving it. Ammonia and HCN are separated by the ususal ways (2), the rest gasses are recirculated. The whole
reaction system is kept below atmospheric pressure (just a little bit).
(1) A tube of 3cm diameter and 60cm length is named lateron.
(2) The "usual ways" of separating ammonia and HCN are lateron named. It is scrubbing with H2SO4 and lye (NaOH).
Other quite similar methods are described, it comes out that the RAPID heating from 260°C to 800°C+ and the RAPID cooling after the pyrolysis are
essential.
If it would not be for the damned high temperatures it would be a good way, but hot tubes capable for temps over 800°C are not so easy to build after
my experience because corrosion of the heating wires becomes a serious problem then. But for it would probably need only a very small tube to do this
it still catches my interest. 3/60cm is industrial, 0,5/15 should suffice with ease and the ceramic tube could be conveniantly made by drilling a hole
into a firebrick. A wider tube filled with porcelain shards for a few cm serving as the "hot zone" would be another possibility.
ideas, ideas....
ORG
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DDTea
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Chloroform and Ammonia DOES, in fact, form Hydrogen Cyanide and was mentioned in War Gases:
| Quote: | Hydrogen Cyanide may be prepared in various ways...or by heating Chloroform with Ammonia,
HCCl3 + H3N --> 3 HCl + HCN
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Naturally, this gives you a mixture of gases--most of which are Hydrogen Chloride. Also, it requires heating, so I imagine the reaction occurs in
the vapor phase--not as a liquid. As such, it is unlikely that mixing liquid ammonia and chloroform would pose a great risk for Cyanide gassing. 
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DDTea
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On the note of Ammonia, Ammonium Cyanide may be something to consider if we're interested in Cyanide salts. It can be prepared by passing
Ammonia gas over hot coals. Naturally, other Cyanide salts--or Hydrogen Cyanide, if need be--can be made from Ammonium Cyanide.
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unionised
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Nitriles hydrolyse under alkaline conditions to give ammonia and the corresponding acid (as the salt).
HCN is the nitrile of formic acid and that's what you will get if you leave ammonia, CHCl3 and a base in solution for long enough. You might get
some cyanide on the way but I don't think the yield will be up to much.
I'm not convinced that the reaction of ammonia with chloroform in solution in water will produce HCN in anything like a hazardous or useful
quantity.
If anyone remembers the original question it was about accidentally producing enough cyanide to kill someone by just mixing the liquids. From that
point of view, the answer is "no".
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DDTea
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Taking this discussion somewhere else... If Ammonia reacts with Chloroform at high temperatures to produce Hydrogen Cyanide and Hydrogen Choride,
could Cyanogen be formed by reacting Hexachloroethane with Ammonia? Or perhaps the aggressive lachrymator Chloroacetonitrile by Ammonia with
1,1,1,2-Tetrachloroethane?
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stygian
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I may have read it on this very forum, it's called the Hoffman isonitrile synthesis, I think it needs a little PTC to go at an appreciable rate
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