[Corvettaholic]

On another thread some guy was asking about potassium cyanide. Now just the name sounds dangerous. Just out of curiousity... what is it? And whats it used for besides killing people? Something industrial, a byproduct of mining, prime ingredient of dental floss?

[Scratch-]

Potassium cyanide   KCN  

Molecular weight:  65.11985
Appearance:  white crystalline solid; deliquescent; faint odor of almonds
Notes:  Extremely poisonous!
Produces deadly HCN gas on contact with acid.
 
Uses:  extraction of coinage metals from ores; complexing agent in electroplating; photography and lithography  

This is what http://antoine.frostburg.edu has on potassium cyanide. Just reading that guys post sent a shiver up my spine and my mind was screaming words like: evil, terrorist and nerve gas...

Heh, if it's an ingredient in dental floss I'm never going to the dentist again! The police where that guy lives aught to be watching him...

[Limpet Chicken]

A recent project of mine has been the preparation of KCN. please don't have a go at me if it's not alright to post this , I know this isn't a poisoners board or anything, but I know what I am doing (I am fully capable of using H2S, which is just as toxic as HCN and frequently do) and I know what I am doing and how to do it safely.

Has anyone tryed it this way:


***EDITED*** NO MORE FULL LENGTH DESCRIPTIONS  -- MITCH

Help would be greatly appreciated  

Plus i forgot, does anybody know how to prepare halogen cyanides? I know the fluorine compound has definately been synthesized,  i'm not sure how though, but I would like to try preparing the chlorine analogue, if it exists. Again, I apologise if the synthesis of horribly toxic chemical reagents for LEGITIMATE uses is stifled here  

[Scratch-]

I don't think the administrators on the forum like people talking about how to make highly toxic or explosive compounds. You may know all about handling the stuff but someone else may come along and see your post and try to make it (Like that guy that was asking how to make it).

[jdurg]

Yes.  We do not allow the discussion of toxic/explosive compound synthesis/extraction on this board simply because of the fact that we have no control over who reads this board.  Let's say some high-schooler is coming on here, reads about some cyanide making process, but doesn't fully understand it all.  Then he/she goes into his high-school chem lab and accidentally release HCN gas throughout the whole school.  The administrators of this board could be held reponsible for that incident.  (Thank you United States Government.   )  Another reason is that even if you "know what you're doing" mistakes can still happen.  I "know what I'm doing" when I'm working with nitrogen triiodide and the alkali metals, but the burn marks on my forearm and the damage to the side of my back-porch shows that accidents can and do happen.  

(Besides, I don't believe that potassium ferricyanide will generate HCN gas when mixed with a strong acid.  I think that it's only binary cyanide salts that will give off the gas.  Though I could be wrong.  It's been a while since I've had to deal with cyanides.  I did chemical inventory at college my freshman year and spent many hours by the cyanide cabinets.  Now, the smell of almonds or anything remotely close to an almond smell gives me a vicious headache).

[Limpet Chicken]

K(Fe)CN is, according to the MSDS, fairly likely to do nasty things with strong acid, while the solid form os more or less guaranteed to do so if heated (and no you can't sue me if it doesn't  )

I have just had a thought though, If it were to be heated in a sealed hydrogen atmosphere with an outlet for the HCN, which could be vented somewhere harmless, then wouldn't  the ferrocyanide (which is reasonlably safe it itself to handle), be reduced to HCN and some sort of weird potassium-iron alloy wfom which the potassium, having a much lower MP could be melted off, leaving you in the end with (assuming you used an alkali metal hydroxide to absorb the HCN)  leave you with: maybe iron so fine as to pyrophoric (which would be neat reducing agent) X-CN, and metallic K?