jiket77 - 16-4-2017 at 22:55
hello everyone, sorry for my english , I'm french and have problem With my keyboard. I Want to make alkali cyanide. I have read all I could on
Sciencemadness about cyanide so please ansWer me anyWay.I Would like that this tread became a reliable reference on cyanide synthesis. I have all
safety needed so no Worry (fume hood and gas mask) I have Potassium ferrocyanides.What is the best to do With ferrocyanide? My other question are
about What I think is the most reliable synthesis .I Wanna try this first:
K4Fe[CN]6 + 6HCl = 4KCl + FeCl2 +6HCN What do you think
about this One?
bubble it in Meoh and NaOH I believe I need to heat the ferrocyanide and HCl to liberate the HCN?
What do you think about H3PO4 on ferrocyanides?
also , any info on this one ? HCONH2 + KOH → KCN + 2H2O
thanks very much 
[Edited on 17-4-2017 by jiket77]
JJay - 16-4-2017 at 23:06
There is a thread on making cyanides: http://www.sciencemadness.org/talk/viewthread.php?tid=23
the method you have suggested is widely regarded as dangerous though it is thought to produce a good product... I think Dan Vizine has done it. IIRC
he said in an earlier post that there is some kind of polymerization caused by distilling the HCN into the base solution that doesn't seem to occur
when first collecting the HCN and then mixing it with the base... I have a large bottle of anhydrous potassium ferrocyanide but haven't tried this
personally and am reluctant to speculate on the subject. Do be wary of armchair pranksters who would like to give you bad advice on your cyanide
syntheses for their own sick amusement though; while most people would not deliberately give you bad advice, there are lots of crazies on the
Internet, and you're bound to run into some sooner or later, especially if you're discussing cyanide....
Chem Player on YouTube posted a few videos on making alkali cyanide from potassium ferrocyanide using methods that don't involve distillation and
apparently produce a product which is suitable for synthesis, as can be seen in some other Chem Player videos.
[Edited on 17-4-2017 by JJay]
jiket77 - 16-4-2017 at 23:23
thanks. I have read all 30 pages. I will post my experiment result when I will have enough info.I would still try it but would rather have more info
j_sum1 - 16-4-2017 at 23:40
chemplayer makes a mixes Na/K cyanide.
Nurdrage has a couple of methods that could be compared.
Cody's lab uses one of Nurdrage's IIRC.
For something like this the advice of someone experienced is indispensible. It helps you sort out the various methods and conflicting advice. Youtube
is a second choice since you actually get to observe what is happening and you are covered for many (but not all) potential surprises. I have learned
a lot from competent youtubers.
Go small scale at first and have good extraction and spill contingencies in lace.
Melgar - 17-4-2017 at 00:47
Ok, here are some suggestions: Learn if it is possible for you to smell cyanide. Most people can, but some can't. The only way to know for sure is
to make a very small amount of it. 50 mg of HCN is the lowest known lethal dose, so 10 mg of ferrocyanide (mostly K and Fe by mass anyway) mixed with
acid should produce a noticeable odor without any danger.
Also, a mix of HCl and H3PO4 may be preferred, since it would precipitate iron as the insoluble phosphate, preventing it from catalyzing any
polymerizations. But I have not tested it to be sure.
tsathoggua1 - 18-4-2017 at 12:39
There is a safer way to do so.
This would be cyanogenic glycoside containing plants, such as many of the genus Prunus (related to the plum, apricot, cherry etc)
Especially certain members of the laurels such as such as Prunus laurocerasus, the cherry laurel, produce various cyanogenic glycosides, plus
hydrolase enzymes within their tissues, especially in the seeds themselves (which take quite a whack with a hammer, brick, etc. to break one open) and
when the leaves are crushed. This would generate much smaller levels of HCN, and it is far less likely to go wrong, if for example, simply crushing
and smelling a leaf or two, pounded to pulp (the cyanogenic glycosides contain a sugar bonded to phenylacetonitrile via an O-linked glycosidic bond,
the hydrolase enzymes in cyanogenic plants generally existing in separate locations within the cytoarchitecture, until wounded or subject to
predation, upon which the tissue damage allows hydrolase and cyanogenic glycosides to mix, creating various nitriles, benzaldehyde (you might want to
choose a species which doesn't in fact produce benzaldehyde, given the overpowering almond scent of the latter could have the potential to dirty the
results of the test).
One thing, if I may go ever so slightly OT, that I've found rather irresponsible, is commercial table salt using potassium ferrocyanide as anti-caking
agent. Not sure about the content, but somebody could easily not expect such to be present and use it in an HCl gas generator with the potential for
bad results. Especially if whatever is being salted or gassed is being done on a large scale. I noticed it in the list of ingredients last night on
one of my salt bottles. Going to have a shot at mixing it with a Fe (III) salt to try and determine the concentration at least roughly via colorimetry
with the resultant prussian blue serving as indicator. The stronger the color the worse the contamination should be.
[Edited on 18-4-2017 by tsathoggua1]
woelen - 18-4-2017 at 22:58
Potassium ferrocyanide does not easily decompose giving HCN. If it did, then it would bot be so easy to get your hands on.
Adding the salt to conc. HCl hardly releases any HCN. Even when you add it to room temperature 50% H2SO4 you do not get more than trace amounts of
HCN.
What you need is heating the stuff with 50% or so H2SO4 and even then the reaction does not proceed smoothly. You also get side-products. If you use
even more concentrated acid, then the reaction proceeds more smoothly, but you also get more side-products. The acid then acts oxidizing as well and
you get CO and (CN)2 as side-products.
If you perform this reaction, please be VERY VERY careful. HCN is really toxic and can easily knock you down. I myself never would try this inside,
not even with very good ventilation. ONLY do this in a good fume hood, or outside on a breezy day.