Sciencemadness Discussion Board - Preparation of cyanides

.And pls do not judge that all are 5th grade failed.

I see no evidence to the contrary.

Well,After reading more about HCN I am almost set in my mind that I will not attempt this.It might endanger others as well.But I would like to know the exact considerations of properties of chemicals involved and precautions to be taken if at all one attempts this.

Thanks for your timely response.

Magpie - 1-3-2012 at 19:05

...Would you think that vacuum distiller is a safe stuff to use ?

What gave you the idea that a vacuum was needed? This would just add another risk factor to an already risky situation. Have you ever heard of a glassware implosion?

Firstly we talk about doing this in a kitchen for gawd sake. Then we throw in fractional distillation and vacuum distillation. And you wonder why people are saying that you aren't qualified to be doing this.

What do you need KCN for anyway? Surely you don't need it for chemistry. I haven't seen any evidence that you know any. Are you making this just for the adrenaline and diarrhea that goes with it?

expInfi - 1-3-2012 at 19:23

Quote: Originally posted by cyanureeves

i think i will have to agree with entropy 51. i dont know about vacuum distilation and we dont even really know if max had a pro helping him behind the scenes. i am not afraid of potassium cyanide but hcn is another monster,all your questions are legit but so are all the replies you are getting. i will eventually proceed just like i know you all will but gentlemen this is freaking auschwitz shit,so patience. cold ethanol will precipitate the salt,i have seen it and done it.it settles at the bottom as a gel that can be dried with a dessicant.

1.By vacuum distillation apparatus , I just was making sure that the gas wont leak out to the air , not the need of a vacuum for the whole thing.
2.The temp control is of at most importance as well.I will not attempt something like this without practicing to regulate the temp at least a 50 times
3.HCN is highly inflammable.Just in the middle if you lose your heart , I have no clue what to do .Would you know how to tackle that situation ?
4.And I would like to know how stable is this HCN in KOH.
5.What are the proportions of masses used ?The video proportion is too dangerous for a me to have.If I try I would need the least possible proportions.Any idea ?

expInfi - 1-3-2012 at 19:27

Quote: Originally posted by Magpie

...Would you think that vacuum distiller is a safe stuff to use ?

If you could answer to the questions I posed that would be great.I am interested in anything challenging.This is one of them.Anyway as I told , I am not so starving for death.And I got enough sense that I cant do this at home.

And now , if possible , come to the point.Thanks

expInfi - 1-3-2012 at 19:34

What gave you the idea that a vacuum was needed?
------------------------------------------------------------------------
I did not have an idea vaccuum was needed.Without pumping out air from it , it will not serve as vacuum distiller.But using such an apparatus will make sure that gas will not leak out(of course , if that is properly handled during the process)

expInfi - 1-3-2012 at 19:38

Or in other words , if any expert here could explain each and every aspect of this process , that would be most beneficial to all who read ( so that illiterates can avoid asking dumb questions)

entropy51 - 1-3-2012 at 19:52

Or in other words , if any expert here could explain each and every aspect of this process , that would be most beneficial to all who read ( so that illiterates can avoid asking dumb questions)

Any reasonably competent amateur chemist could read this thread and have a fairly good idea how to proceed.

The nature of your questions suggests that you may be lacking in one of these two proficiencies.

Anyone who needs to be spoonfed about making cyanide should not attempt to make cyanide.

expInfi - 1-3-2012 at 20:11

Gawd ! Is Knowledge too heavy that it occupies the whole head and can't convey it in a way it deserves.I was reading the whole thread and I can sense the danger of risks involved.

Can you pls answer : Being an expert , if you would do Max's method ( I read his posts about his proportions , HCN leaking and unable to store it properly and so on ) how exactly would you do ?

expInfi - 1-3-2012 at 20:39

http://www.sciencemadness.org/talk/viewthread.php?tid=23&...

Ok.I got my answers.

entropy51 - 1-3-2012 at 20:40

Gawd ! Is Knowledge too heavy that it occupies the whole head and can't convey it in a way it deserves.I was reading the whole thread and I can sense the danger of risks involved.

Can you pls answer : Being an expert , if you would do Max's method ( I read his posts about his proportions , HCN leaking and unable to store it properly and so on ) how exactly would you do ?

More than a few members find it a little odd when a new member's first post is an enquiry regarding cyanide. This is evident if you read the posts. You joined a week ago and have 18 posts, all related to cyanide. As I said, some of us find it a little odd.

Magpie - 1-3-2012 at 21:54

Emotions aside we are just trying to prevent you from accidentally killing yourself, your friends, and/or your family.

When you say you don't know the fundamentals of an acid-base reaction, ie, HCN-KOH, then I know you have little to no chemistry training. That is not a good place to be when attempting to make cyanide.

Would you pull a man off the street and ask him to do an appendectomy on you based on some written instructions that you just handed him?

Lambda-Eyde - 1-3-2012 at 23:58

Also, I want to mention that Max (myfanwy94) actually killed himself with phosgene. I guess it was just plain luck that it didn't happen earlier with the cyanide.

expInfi - 2-3-2012 at 04:10

Quote: Originally posted by Magpie

Emotions aside we are just trying to prevent you from accidentally killing yourself, your friends, and/or your family.

When you say you don't know the fundamentals of an acid-base reaction, ie, HCN-KOH, then I know you have little to no chemistry training. That is not a good place to be when attempting to make cyanide.

Would you pull a man off the street and ask him to do an appendectomy on you based on some written instructions that you just handed him?

I understand that and appreciate it.You develop interest in certain things when you come to know that it appears almost impossible to you for the first time.And that is the reason I am all into this cyanide thing.Just to clarify the other kind of interest is to climb Kilimanjaro.Well , just to tell you there ppl are of different choices and risks wont stop them.I think I made all my efforts to convey you that I am not trying to kill myself after making cyanide if at all any of you felt so ...Then I dont have to do anything ,but just let the HCN leak and I stand there , why should I need KCN at all ?

I would read more on acid-base reaction.Thanks for your input on that..[If you believe it or not , I had 99% marks in chemistry in graduation.Just that ,its not my profession that I lost the touch.But when I read more now , it does not look like French to me and it appears more exciting that it used to when I was a student]

expInfi - 2-3-2012 at 04:24

The acid and base reaction ,to the limit I know,is driven by the valence of ions.Philosophically , any system try to reach a state of least entropy.

HCN + KOH - > H2O + KCN.

But I am not really sure how stable is this solution.For instance I do not have any clarity at what temp this can again start release HCN.And if this is exothermic in nature .If not this , the reverse will be exothermic ? Its those details I wish to know.

Lambda-Eyde - 2-3-2012 at 04:32

If you have recently developed an interest in chemistry, then start off with something that's less likely to kill you or people/animals in your vicinity - cyanide scores pretty high in that regard. There are a lot of interesting things to do in chemistry - making cyanide is one of them, but it is not a beginner's experiment you do for fun.

Well , just to tell you there ppl are of different choices and risks wont stop them.

If the risks won't stop you, then I don't think chemistry is a suitable hobby for you.

I think I made all my efforts to convey you that I am not trying to kill myself after making cyanide if at all any of you felt so ...Then I dont have to do anything ,but just let the HCN leak and I stand there , why should I need KCN at all ?

The problem is that you don't have to try to kill yourself with cyanide. If you're not prepared for the dangers then it will kill you. As others have said, if you don't even know the basics of acid-base chemistry it's a very good indicator that you shouldn't take this beyond the theoretical level.

Also, for all we know, you aren't going to kill yourself... I'm sure you understand we are skeptical against new members who are obsessed with cyanides.

expInfi - 2-3-2012 at 04:41

Oh God ! Its tiring.I would let the experts talk on dangers involved , instead of talking something about :
Stability of KCN solution.

And if someone has the kindness to convey the how to practically deal with of KCN solution before it is precipitated using cold ethanol, I would read that.

expInfi - 2-3-2012 at 05:11

Quote: Originally posted by Lambda-Eyde

Well , just to tell you there ppl are of different choices and risks wont stop them.

If the risks won't stop you, then I don't think chemistry is a suitable hobby for you.

Yes I understand the skepticism involved and even I was when I read a few posts asking where to get the apparatus and so on.

And I am sure that I am not going to try this coz though I am willing to take the risk , it might cause harm to others as well.So ethically I lose the right to do so , until I am confident that I can do this neatly.

madmanhere - 2-3-2012 at 05:36

Even though I am a noob, I find your statements lacking logic. You say you are not willing to take the risk until you are confident enough to conduct the experiment in a safe way. How exactly do you plan to become confident? Just by reading a lot on the experiment? Pure theoretical knowledge?

The guys over here are of the view that one should work on less hazardous experiments, gain experience and then move on to the one in question.

I'd say it's better you stop questioning the experts/ oldies of the forum and just listen for a while. Else you are never going to get an answer. At least go through all the posts on this thread and I'm sure you will get the necessary info.

PS: I have all the reagents and apparatus needed for this experiment lying next to me but have no plans to carry out the reaction in an appreciable scale until I'm done with some experiments given in woelen's website http://woelen.homescience.net/science/chem/index.html
By the way, I have 2 years of practical knowledge in chemistry.

Peace.

[Edited on 2-3-2012 by madmanhere]

expInfi - 2-3-2012 at 05:42

Quote: Originally posted by madmanhere

expInfi - 2-3-2012 at 05:48

Quote: Originally posted by madmanhere

And what on earth made you think that I am going to do this now ????Am I writing in French or what ?

Or is it that I cant ask about stability of KCN solution at OR Do I need to go and make some posts in a less hazardous threads that I can get an answer ! Jeez !

expInfi - 2-3-2012 at 06:08

Ok.Let me listen to the ppl here.I would just try to prepare some harmless things first.And would read more here.My over enthusiasm is shaken.No quick root to get knowledge

expInfi - 3-3-2012 at 12:48

Can someone explain equations of reactions upon the addition of ethanol into KCN solution ?I read in a previous post that it is benzoin condensation.But that needs a CHO group(isn't it ?) and ethanol is an alchahol.

entropy51 - 3-3-2012 at 17:32

Can someone explain equations of reactions upon the addition of ethanol into KCN solution ?I read in a previous post that it is benzoin condensation.But that needs a CHO group(isn't it ?) and ethanol is an alchahol.

No equations needed. Just look up the solubility data.

Post a link to where you read that it was a benzoin condensation, why don't you?

expInfi - 3-3-2012 at 19:02

Quote: Originally posted by entropy51

No equations needed. Just look up the solubility data.

Post a link to where you read that it was a benzoin condensation, why don't you?

Sorry.I read : Cyanide that was prepared by fusing ferro+C+Pot.Carbonate mixture, used for benzoin condensation and it gave a good yield of benzoin.Thats what it was when I referred back to.
I will look up the solubility data.
[If you could provide a suitable link , that would be great ]

[Edited on 4-3-2012 by expInfi]

madmanhere - 3-3-2012 at 21:56

Solubility in ethanol- 0.57g/100ml @ 19.5 'C
MSDS for KCN: http://www.sciencelab.com/msds.php?msdsId=9927707

expInfi - 3-3-2012 at 22:38

Quote: Originally posted by madmanhere

Solubility in ethanol- 0.57g/100ml @ 19.5 'C
MSDS for KCN: http://www.sciencelab.com/msds.php?msdsId=9927707

Thank you !

1.What would you derive from this statement :
Potassium cyanide + hydrogen cyanide is a frictioin and impact-sensitive explosive in the context of "When liquid HCN drops to NaOH(aqs) it gives KCN and H2O."

2.Is this acid base reaction non-reversible below 26C while HCN inflow is in progress and after that?

3.Is temp the only factor which determines the reversibility of this reaction ? What is the role of Ph of NaOH solution (in other words the concentration) ?

[Edited on 4-3-2012 by expInfi]

expInfi - 3-3-2012 at 22:42

I am trying to understand how can we prevent the KCN Solution from starting to release HCN back.

Nicodem - 4-3-2012 at 03:20

I am trying to understand how can we prevent the KCN Solution from starting to release HCN back.

The pKa of the cyanide ion is 9.40 in water ( http://research.chem.psu.edu/brpgroup/pKa_compilation.pdf ). This number is enough to answer all of your questions above, except the one about temperature.

(It took me exactly 25 seconds of googling to find this information while you rather spent your time double-posting instead of looking for it. Makes me wander if you really have the skills and reason enough to mess with potassium cyanide?)

expInfi - 4-3-2012 at 08:14

Quote: Originally posted by Nicodem

I am trying to understand how can we prevent the KCN Solution from starting to release HCN back.

I am sure that I do not have the skill to mess up with cyanide.Neither I am going to.I am trying to understand the theory.Thanks for the link.

AndersHoveland - 7-3-2012 at 05:08

from chloroform and ammonia

CHCl3 + 5NH3 --> NH4CN + 4NH4Cl

AJKOER - 7-3-2012 at 07:00

Quote: Originally posted by AndersHoveland

from chloroform and ammonia

CHCl3 + 5NH3 --> NH4CN + 4NH4Cl

Do you have a reference, as the reaction as written is occurring in a non-aqueous medium.

Also, I previously noted a parallel reaction in an aqueous environment with CHI3, forming NH4COO as a path to HCN.

CHI3 + 4 NH3 + 2 H2O ---> 3 NH4I + NH4CHOO

Now, NH4CHOO --Heat--> HCN + 2 H2O

So, is there an intermediary in your proposed reaction as well? Does CHI3 also work?

I am not a total believer as there is a significant secondary reaction:

NH4CHOO --Heat--> NH3 + H2O + CO

[Edited on 7-3-2012 by AJKOER]

AndersHoveland - 9-3-2012 at 02:41

Chloroform will react with ammonia much more readily than chloromethane will.

http://www.sciencemadness.org/talk/viewthread.php?tid=6915

Quote: Originally posted by Polverone

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

It is not really extremely difficult to prepare anhydrous NH3 gas (NH4Cl + CaO).

While cyanide can be produced in the presence of water, less water gives much better yields. One would think that the yields from CHCl3 would be higher than CHI3 in the presence of water, because CHI3 is much more reactive, and has a tendancy to just readily hydrolyse in water by itself (chloroform takes many days to hydrolyse in water, and only then if it is completely dissolved since it has a low solubility)

The room temperature reaction between chloroform and ammonia is still relatively slow (more than 2 days).

Quote:

Ammonium cyanide is also formed by passing a mixture of the vapors of chloroform and ammonia gas through a tube heated to 300 °. When chloroform is passed with excess of ammonia through a heated tube, no action takes place till the temperature approaches a red heat, when chloride and cyanide of ammonium are formed.

Quote:

Hydrogen cyanide is formed by passing ammonia and chloroform vapour through a hot tube Heintz, Ann. 100, 369 , or by heating chloroform and alcoholic ammonia to 180-190 °. Cloez, Jahresber. 1858, 345.

Supposedly heating formic acid with dry ammonium chloride can form HCN. Pelouze and Döbereiner, Ann. 2, 90

An aqueous solution of copper acetate with ammonia heated to 180 ° in a sealed tube for two hours gives cuprous cyanide, Cu2(CN)2. Vittenet, Bull

Heating urea with zinc dust forms zinc cyanide.
Aufschläger, Monats. 13, 268

[Edited on 9-3-2012 by AndersHoveland]

seashell1982 - 12-3-2012 at 19:03

What type of gas mask should I use to protect against HCN? Link? Thanks.

entropy51 - 12-3-2012 at 19:15

Quote: Originally posted by RisingSun96815

What type of gas mask should I use to protect against HCN? Link? Thanks.

You would trust a gas mask to protect you against HCN? Seriously?

Be sure the authorities know how to contact your next of kin.

AndersHoveland - 12-3-2012 at 20:34

One would need a specially designed fumehood, ideally the type that is completely insulated, with gloves built into the window. And even then a respirator (gas mask) would still be advised.

AJKOER - 13-3-2012 at 10:13

AndersHoveland:

Thanks for the wealth of info on the CHCl3 + NH3 reaction.

(I'm glad I dragged it out of you)

Mira - 12-4-2012 at 05:15

I am surprised to see the over estimation of toxicity around HCN given in this thread.I have worked with HCN with fumehood and without.I mean I had taken the flask in my hand and walked for a few seconds to the other chamber with heated H3PO4 and Ferro.cyanide in it without a fumehood.I understand the indication of low safety system I worked in ,that I am delivering here.But I fear if a chemist actually believes that it is something that you be around and you are going to die , is a kind of silly.But , yes I understand if that over estimation is done to prevent people without proper background to get into a trap that they are not really aware of.

cyanureeves - 12-4-2012 at 15:54

Mira i am all ears,then you have distilled ferrocyanide with H3PO4? did you distill it into hydroxide and ethanol? please elaborate and do you mean that acid and ferrocyanide will not release gas without heat?

seashell1982 - 28-4-2012 at 07:12

Quote: Originally posted by Magpie

I suggest you test it using a Prussian Blue test as follows:

1.Place about 1 mL of water in a small test tube.
2. Add a smidgen (few mg) of FeSO4*7H20 or other soluble ferrous salt and stir until dissolved.
3. Acidify with a few drops of 1M HCl.
4. Add a smidgen of your product and stir.

An intense dark blue color indicates the presence of cyanide.

I should also point out that it is necessary for some ferric ions be present also. So I add a drop or two of 0.5M FeCl3 to be sure.

How should I dispose of this when I'm finished? It sounds like there is a small amount, but because there is some ferric chloride I don't won't to put it down the drain.

cyanureeves - 28-4-2012 at 09:12

i think household bleach will neutralize cyanide. iron chloride isnt that toxic is it?

seashell1982 - 28-4-2012 at 18:15

Quote: Originally posted by cyanureeves

i think household bleach will neutralize cyanide. iron chloride isnt that toxic is it?

From what I've read elsewhere, ferric chloride etches copper, and therefore could damage plumbing.

Zan Divine - 3-6-2012 at 14:45

Cyanureeves,
What she meant is that after you add your acid to your ferrocyanide, no HCN is evolved. HCN comes out as the temperature is increased.

Bleach is the suggested reagent to destroy cyanide. Oxidizes it to cyanate. pH control is important to prevent runaway reaction.

Mira,
I couldn't agree more. I've synthesized 200 g lots of liquid HCN a half dozen times on an open benchtop. The reaction vessel was a closed system and a vent tube ran out the window.

Incidentally, my experience is that HCN vapors lead directly into aqueous NaOH always give contamination by black polymers. On the other hand, if I collect the liquid HCN and then drip that into aq. NaOH I get a clear solution.

Remember never to collect it as an anhydrous form. Make sure some water is present in the collector (a few drops of sulfuric acid is also a good idea) to prevent uncontrolled polymerization.

I'm genetically predisposed to being able to smell cyanide. I love the smell. Reminds me of delicious almond pastries.

OK...on to the anecdotal stuff. My former boss got a mouthful of anhydrous HCN at his job at Dupont decades back. He spit it out and rinsed his mouth out. He's pushing 80 today. I got a big lungful of HCN gas maybe 20 years ago. The room started to go dim. I took a step toward a labmate to say "cyanide" and just as quickly as it started it was done. Yeah, cyanides are poisonous, but not a big deal by any stretch if you have the appropriate glassware, grease your joints, use keck clips & and take common sense precautions.

[Edited on 4-6-2012 by Zan Divine]

cyanureeves - 3-6-2012 at 17:50

thanks divine and i didnt know mira was a woman. i am about ready to go ahead with this process but use phosphoric acid instead. i got a laser thermometer to check the heat and make sure it doesnt boil. i am going to test run with water and set my hot plate to just under boiling heat and have it ready. i got stoppers that fit the thermometer port where i will add a small amount of water for when it starts getting dry like myfanwy experienced. i want so much to see cyanide dissolve gold so,so bad because i think it is almost magical. i will be so happy to have this experience so much that i have it up there with a grand canyon and a carribean experience. when this will be accomplished then i will learn more about acid/base extractions.as it is right now i am not disappointed with the bubbling hcn through ethanol/hydroxide method because it gold plates really good but i know it can be better.

Zan Divine - 4-6-2012 at 05:34

Typical run:
422 g (1 mol) K4[Fe(CN)6] added to 2 L round bottom with stir-bar. Add a solution of conc. H2SO4 (200 mL) in H2O (600 mL) in one portion. Attach distillation head cooled with ice-water. Reaction appratus vented by tubing running out the window. Slowly heat the stirred blue suspension. You don't need to go much above 50 - 60 degrees C. Foaming occurs in the first hour or longer as cyanide is distilled out and collected in an ice-cooled flask containing 5 mL H2O and a couple mL H2SO4. Foaming subsides after a couple hours and then the suspension thickens. Adjust stirring as necessary. After 4 hours, 147 g HCN (80%) has been collected as a water-white liquid.

Dispose of residue in accordance with local laws.

Depending on your intended use, gold dissolution, electroplating bath, etc. you can convert it to the appropriate salt.

[Edited on 4-6-2012 by Zan Divine]

kmno4 - 4-6-2012 at 13:08

Typical run:
(...)

This "thypical" procedure will not work because of obvious reasons.

cyanureeves - 4-6-2012 at 16:11

and the obvious reason would be all the hcn flying out the window. wouldn't it? unless the reaction vessel is the recipient vessel but regardless, why the ventilation?if it's because of quantities of acids then i dont know why.

[Edited on 5-6-2012 by cyanureeves]

Zan Divine - 4-6-2012 at 18:57

Quote: Originally posted by kmno4

Typical run:
(...)

This "thypical" procedure will not work because of obvious reasons.

You both don't seem to grasp the fact that I was reporting an actual run. Why would HCN "fly out the window"?. The cooling water in the condenser is below the bp of HCN and the receiver certainly is way below.

When I discuss preparations, they are preparations that I have done. As I said earlier, I've done this a half dozen times. A little background...I've probably got as much or more experience with synthesis as anybody here. 26 years of nothing but custom synthesis of cancer, malaria & AIDS drugs, oxygen-selective absorbents, organometallics, pesticides, labeled compounds. You name it, I've made it. So, before you say that something I'm saying is not legitimate, you should be prepared to back your statement up.

The vent line is obvious, isn't it? You don't want a sealed system that can pressurize. Unless you are doing a pressure reaction, reaction vessels are always vented one way or another.

You do know the bp of HCN, don't you?

Why would anyone doubt the veracity of this trivial preparation?

[Edited on 5-6-2012 by Zan Divine]

seashell1982 - 6-6-2012 at 04:37

Bleach is the suggested reagent to destroy cyanide. Oxidizes it to cyanate. pH control is important to prevent runaway reaction.

How do you control the pH? I'm assuming you're adding some kind of cyanide salt to household bleach (pH 12.6). What exactly do you mean by runaway reaction?

Zan Divine - 6-6-2012 at 07:39

Take a look at:
http://shorinternational.com/cyanodestruct.php

The reaction is complex. At different pH's it gives different products. pH can be controlled by the usual methods (add some NaOH or HCl). But, read the cautions...

If pH is too low you may produce ClCN. If pH is too high, reaction is very fast and excessive N2 pressure may result.

[Edited on 6-6-2012 by Zan Divine]

kmno4 - 6-6-2012 at 13:06

Why would anyone doubt the veracity of this trivial preparation?

Because its impossible to obtain given amount of HCN from given amounts of substrates under given conditions.
I wrote too many posts on this topic and I am just bored with it, I do not want to explain the same things another time.

Zan Divine - 6-6-2012 at 20:33

I'll bet you're fixating on the acid concentration. I didn't bother mentioning that I add additional water during the foaming stage to keep it out of the condenser. Never realized it helped.

Anyway, I'm telling you as a flat-out fact that this was done, multiple times with consistent yields.

You can actually watch a similar prep. with H3PO4 on youtube
(http://www.youtube.com/watch?v=K5NuqpdYDhE). He gets 10 g of NaCN (after crystallization) from 22.7 g ferrocyanide. You should know how low the recovery is when crystallizing it out of alcohol. He probably had 8 or 9 g of HCN to get 10 g of crystallized NaCN.
That would scale up to him getting a bare minimum of ~148 g HCN from 420 g ferrocyanide, and possibly over 160 g. Very much in line with my results.

You can doubt me if you want, and then doubt your own eyes.

Maybe you are referring to the (incorrect) assertion that only half the HCN comes out without catalysis by copper salts/copper metal?

Working chemists tend to learn early on that just because it says somewhere that something proceeds in this or that yield, your mileage may vary... (and, if you're working from a patent, sometimes it's just fiction).

Writing many posts is certainly valuable, however I tend to view actual experimental results with more regard.

[Edited on 7-6-2012 by Zan Divine]

AJKOER - 30-8-2012 at 05:02

A simple direct and proven approach (but gaseous requiring precautions and use of an expensive catalyst), try to replicate the industrial Andrussow process either on a micro scale or larger. Per Wiki, to quote:

"The Andrussow process is an industrial process for the production of hydrogen cyanide from methane and ammonia in the presence of oxygen and a platinum catalyst.[1][2]

CH4 + NH3 + 1.5 O2 → HCN + 3 H2O

Side Reactions

This reaction is very exothermic. The change of Enthalpy of this reaction is equal to -481.06 kJ[3]. The heat provided by the main reaction serves as a catalyst for other side reactions.

CH4 + H2O → CO + 3 H2
2 CH4 + 3 O2 → 2 CO + 4 H2O
4 NH3 + 3 O2 → 2 N2 + 6 H2O

This side reactions can be reduced by only short exposures to the catalyst."

Link: http://en.wikipedia.org/wiki/Andrussow_process

The created HCN could be immediately be reacted with NaOH (or perhaps more ammonia). Obviously, this reaction should only be attempted with appropriate safety equipment and ventilation being a gases reaction process.

Also, I suspect one may be able to successfully substitute C2H6 for CH4 with increasing air/O2 flow.

So, if one made a home-made Pt catalyst (Platinum jewelry turned into powder, or better, dissolved and freshly precipitated), even though less than the perfect catalyst, the reaction is reported as exothermic and best with "only short exposure to the catalyst", so a home-made low efficiency Pt catalyst may work. One may be able also to use a Ag/Al2O3 based catalyst (see full thesis at http://research.cems.umn.edu/schmidt/schmidtpapers/thesis/Sa... ). I would make such a Silver catalyst by the thermal decomposition of Silver oxalate (Aluminium oxalate).

However, further research does indicate that the process is intricate requiring a heat exchanger (see "Alternative catalyst supports for hydrogen cyanide synthesis and ammonia oxidation" by DA Hichkman, M Huff and LD Schmidt, published in Ind. Eng. Chem. Res., 1993, 32 (5), pp 809–817. Link: http://pubs.acs.org/doi/abs/10.1021/ie00017a007 ) to avoid a thermal decomposition of the highly unstable HCN:

HCN + H2O --> NH3 + CO

[Edited on 30-8-2012 by AJKOER]

carlos_souza - 24-12-2012 at 05:33

Quote: Originally posted by Polverone

I know I've told some people about it, but I can't seem to find my more refined NaCN preparation writeup here.

The way I do it now, for making larger quantities, is to mix powdered urea or cyanuric acid with NaHCO3 and heat, covered, until it's melted...

Hi Polverone.
Actually, do you not heat the sodium bicarbonate to produce sodium carbonate before mix with the cyanuric acid?

My report

robertstar - 5-1-2013 at 07:57

I needed some grams of NaCN for an experience of coating of copper, then I tried to produce it, boiling potassium ferrocyanide with phosphoric acid, but it did not work because I used a makeshift apparatus. The mixture was boiled in a kitasato flask whose nozzle was closed with a rubber stopper. The output of kitasato was connected through a silicone tube to an improvised condenser done with two turns of copper pipe in a bucket full of ice water. The condenser output was dripping in a flask with concentrated solution of NaOH.
My heating source was a gas cooking stove. It was impossible to control the temperature. The result was that too water was evaporated, the solution dried soon and I was with very dilute NaOH solution, and besides, the HCN was not condensed, which came in the form of gas at the end of the condenser. The ambient temperature was 30° C.
I concluded that it is not possible to distillate HCN with improvised apparatus unless the ambient temperature is very low.
I then decided to try the method described by the author of this topic, Polverone.
I built a small furnace with bricks stacked.
In my first attempt, I used a can of 20 cm length by 8 cm in diameter. The coal involved the can until its half.
I bought sodium bicarbonate in the pharmacy where it is sold as a stomach antacid. I bought acid isocyanuric in a store of products for treatment of pools, as chlorine stabilizer, but I suspect that he was with the expiry date. He came grainy and I turned 50 g powder gradually putting inside a small plastic bag, beating with a hammer and passing through a fine sieve.
I lit the coal, put 50 g of sodium bicarbonate in the can and left waiting for a few minutes until it was converted into sodium carbonate. Not knowing whether or not the conversion had been completed, I added the acid isocyanuric.
After a few minutes, everything was turned into a boiling liquid. At this point, I added about 10 g of powdered charcoal. To transform coal into powder, I used a sandpaper, after passing through a fine sieve.
To close the can, I used a metal plate. After some time, the can was red and began to bend due to the weight of the metal plate. After 2 hours the can disintegrated at half its height. Then, I removed the bottom of the can from the fire and let it cool. It was possible to feel the smell of HCN in solid contained in the bottom of the can. The solid was scraped from the bottom of the can and placed inside a glass jar, covered with 100 mL of water at room temperature and stirring occasionally for 2 hours. The liquid also emitted the odor of HCN.
After that, the liquid was filtered out with filter paper coffee. I didn’t do any test with this filtrate.
I added 200 mL of ethanol and mixed. At that moment, it was possible to see a remnant of coal that escaped filtering. It was formed a colorless biphasic liquid solution with the bottom phase with a volume much smaller than water that was there before. There was no crystallization. The ambient temperature was about 30° C.
The solution was filtered. I believed that the lower phase was not to pass the filter, but it was a mistake, as I could see on the second try. I have lost most of their product. When filtering was too slow, I spilled the contents of the filter into a bowl of steel. I heated the bowl with a heat gun until result in a white salt. The mass of this salt was about 4 g. I kept in a closed bottle of 100 ml. Later, when opening the bottle, I felt the odor of ammonia.
Some of this salt was dissolved in water and then mixed with a slightly acidic solution of iron sulphate and showed a light blue color. I poured the rest of the solution in a vinegar solution and it was bubbled.
We conclude that this attempt I got a bit of cyanide and a lot of impurity, probably because I had to stop the warming.
For the second attempt, I searched a container that resists heat. I bought an old fire extinguisher of 8 cm diameter, 30 cm height and steel plate 4 mm thick. I cut it at a height of 20 cm and I got a container of 1 L. As it is rounded background, I used a piece of metal shaped ring to stop him standing. I tried to remove as much rust inside it. To cap it I used the same metal plate.
As I suspected that my isocyanuric acid was expired, I bought granulated urea in a store as fertilizer and turned 150 grams powder with the aid of a hammer.
I heated baking soda in a bowl of steel in the kitchen stove, stirring continuously until it ceased gas emissions, to turn it into sodium carbonate.
I mixed 150 grams of urea powder with 100 grams of sodium carbonate and 50 grams of coal powder, placed the mixture in the container and heated it in the same furnace with some modifications.
After half an hour, the mixture powder was completely melted and boiling. When the lid was removed to check on, the gas into the container was burned. Even it was closed, sometimes a jet of yellow fire went out underneath the lid.
After the coal was burning, it was easy to keep it, just every 15 minutes to put some coal in it.
As time passed, the mixture was becoming thicker, but still bubbling.
I decided to leave until the bubbles ended, which occurred after 6 hours. I left it 1 more hour to finish burning the coal that was in the furnace.
A total of seven hours of heating has been consumed 7.5 kg of charcoal. The container took 1 hour to cool. It suffered no apparent damage.
The black product that resulted in the bottom of the container was very hard. In the interior side of the container, just above the bottom, was formed a crystalline solid. Not knowing what was this salt that was formed on the side, I removed it separately from the background layer. The bottom layer was very difficult to remove. I used a large screwdriver hitting the cable with a rubber hammer. I removed about 20 g of product of the side and somewhere around 100 g from the background that were placed in different vials. The odor of HCN was strong in both.
After turn them powder with the aid of a hammer, I added 100 ml of water to the 20 g and 300 mL to 100 g. The water, that was cold, has warmed. I stirred the solutions sometimes for about 1 hour. The solutions were separately filtered out using filter paper coffee. The solutions were a slightly yellowish color. Both solutions gave off smell of HCN.
I added, separately, a few drops of each solution in a green slightly acidic solution of iron sulfate and mixed, getting a dark blue solution, very different from that obtained with the solution of my first attempt.
I poured vinegar on the filtered solutions and they not bubbled.
I heated the solutions and felt no ammonia odor.
After these tests, I mixed the solutions and added 800 mL of ethanol. It was formed a liquid heterogeneous solution of two phases. The low phase was a volume of approximately 200 mL. There was no crystallization. The ambient temperature was around 30 ° C.
At this time, I not filtered out, as on the first try, because I realized that both phases passed through the filter. I just put the solution in the freezer. After 1 hour, the part corresponding to bottom liquid phase were crystallized. I poured the liquid into another container and with a steel spoon I removed the crystallized salt, putting it on a few sheets of paper towel. I spread salt on paper towel and put other leaves on top, pressing. I did it until the paper towel absorbs the most of the liquid.
The salt was exposed to air for about 1 hour until the smell of alcohol has disappeared, but the salt was still wet.
After that, I wrapped the salt on a filter paper and put it in a closed glass jar with poured about 100 g of silica gel in the bottom of it.
In the next day, the top of the salt was dry, but the background was still wet. I mixed the salt and closed the bottle again.
I dropped it into the glass drying for five days stirring once a day.
After that time, the salt apparently was dry and its mass was 53 grams.
The salt remains exhaling odor of HCN. I believe that my product is mostly NaCN, although I do not know which its purity is.
Some pictures of the experiments can be see in the following links.
First try:
http://s1293.beta.photobucket.com/user/robertstar1971/librar...
Second try:
http://s1293.beta.photobucket.com/user/robertstar1971/librar...

Hexavalent - 5-1-2013 at 09:02

You may be able to recrystallize your crude NaCN if necessary to further purify it, and you could filter over diatomaceous earth or a similar material to remove the suspended carbon.

How well did the covers fit over the containers?

BTW, you repeatedly mention that you "smell" HCN (almonds?). If you can smell it, you are inhaling it - be careful.

robertstar - 5-1-2013 at 10:58

I believe it will not be necessary to purify the NaCN. The lid just rested on top of the container. When I smell the HCN, I take away the source, preventing most aspire.

ktcd - 29-1-2013 at 22:19

I don't understand, if CNCl + H2O -> HOCl + HCN (which I would think thermodynamically unfavorable, but anyways

, shouldn't HOCN + HCl -> HOCl + HCN

UnintentionalChaos - 30-1-2013 at 00:05

Quote: Originally posted by ktcd

I don't understand, if CNCl + H2O -> HOCl + HCN (which I would think thermodynamically unfavorable, but anyways

, shouldn't HOCN + HCl -> HOCl + HCN

Because CNCl + H2O does not form HCN and hypochlorous acid. It form HOCN and HCl.

Zan Divine - 13-2-2013 at 10:55

Every time I have prepared NaCN by leading liquid/gaseous HCN directly from my sulfuric acid-ferrocyanide reactor into aqueous NaOH I end up with a brown-black product.

If I collect the HCN as liquid (stabilized w/ H2SO4) and then drop that into aqueous NaOH it stays almost colorless. Even when I collected unstabilized liquid HCN, it too gave no brown-black products.

I'm assuming you guys know that unstabilized HCN may undergo spontaneous polymerization. Be aware that a tiny trace of the CN anion in the form of a dissolved speck of NaCN will catalyze this.

Anyway, this is obviously a polymerization problem. Anybody else seen the same thing?

kmno4 - 13-2-2013 at 12:38

These brown matters are known issues for very long time.
I also noticed this and can confirm it.
It is easy way to avoid this - introduce HCN to solution of KOH (NaOH) in ethanol.
NaOH is better because nice, crystalline hydrate of NaCN separates. It is unstable and must be quickly dried (vacuum or very quick drying in steel pot at ~90 C with continuous stirring with a spoon). Snow-white product, strongly hygroscopic can be obtained.

Zan Divine - 14-2-2013 at 18:37

That's the classical method for isolating KCN or NaCN.

Absolute ethanol is very difficult to come by here in the US. The best most can find is about 90% (as Everclear alcohol I guess). Any road to absolute EtOH from there is laborious. I've never needed my cyanide salts as crystalline solids, fortunately.

The thing I find striking is that collection of the neat HCN and then subsequent addition to aqueous base circumvents the brown-black horror. Presumably, the HCN contains the same components as the vapor it is condensed from. But that can't really be true. Short lived transient species?

franklyn - 18-2-2013 at 18:11

All Cyanide compounds may be derived from Cyanogen. NΞC-CΞN

Cyanogen is produced by dry distillation of Ammonium Oxalate
(NH4)2C2O4 => 4H2O + NC-CN
done in a glycol or glycerine to sequester the water produced.

Google this => "Ammonium Oxalate" Cyanogen

From : Commercial Organic Analysis - 1896
http://books.google.com/books?id=ppDPAAAAMAAJ&pg=PA424&a...

It is an old preparation , confirmed on the second page
From : The Chemistry of Cyanogen Compounds - 1915
http://books.google.com/books?id=vW86AAAAMAAJ&pg=PA2&...

From : Theoretical organic chemistry - 1916
http://books.google.com/books?id=c8wQAQAAMAAJ&pg=PA210&a...

From : A Textbook of Organic Chemistry - 1921
http://books.google.com/books?id=bkQAAAAAYAAJ&pg=PA409&a...

.

robertstar - 20-2-2013 at 01:37

Hello, I described my experience of producing NaCN few posts ago.
Due to the strong odor of HCN, I believed that its purity was considerable, but it did not work satisfactorily in the process of electroplanting.
Anyone knows any indicator for the titration of cyanide with silver nitrate that can be used to replace the rhodanine?
I tried with potassium iodide, but did not work.

[Edited on 20-2-2013 by robertstar]

Magpie - 20-2-2013 at 09:26

Quote: Originally posted by robertstar

Anyone knows any indicator for the titration of cyanide with silver nitrate that can be used to replace the rhodanine?
I tried with potassium iodide, but did not work.

I would recommend the Liebig method, as I have used it before with apparent success. I found it in "Quantitative Analysis," by Pierce and Haenisch, 3rd ed. You may also be able to find it by searching Google Books.

Liebig Method for Cyanides
To the dissolved sample, which should contain 6-8 mmol of cyanide ion, add 30-40 mmol of ammonium hydroxide and 0.1-0.2g KI, and dilute to a volume of 200mL. Titrate with standard 0.1M AgNO3 until the addition of 1 drop of reagent causes the appearance of a permanent turbidity in the solution.

Prior to the stoichiometric point, a soluble silver cyanide complex ion is formed:

Ag+ + 2CN- -----> Ag(CN)2-

robertstar - 20-2-2013 at 16:22

Thank you Magpie.
I didn't found the book on google, but I found this document:
http://nvlpubs.nist.gov/nistpubs/jres/7/jresv7n5p913_A2b.pdf
As I understand it was originally used only silver nitrate and the indication of the end of the titration occurred when the solution became turbid. I decided to test ...
I dissolved 1 g of my product in 100 ml of distilled water. The obtained solution was colorless. Next, I removed 10 mL and added 90 ml of distilled water to obtain 100 mL of a solution with 1 g/L of concentration. I used 20 ml of this solution to the titration. In this solution I instilled a drop of solution of 0.5 N sodium hydroxide to avoid the presence of HCN.I used a 0.01 N silver nitrate solution.
The problem is that even just a drop of the silver nitrate solution becomes the solution turbid. For turbid I mean it ceases to be transparent, assuming a brownish. However, after only about 5 mL there was precipitation of a gray solid.
With potassium iodide, the solution takes on a yellowish color after receiving the first drop of the solution of silver nitrate.
I'll still read the document carefully and perhaps make other attempts titration ...
I believe that my product is mostly sodium carbonate.
You know some form of separating the sodium cyanide from sodium carbonate without involving distillation?

[Edited on 21-2-2013 by robertstar]

[Edited on 21-2-2013 by robertstar]

[Edited on 21-2-2013 by robertstar]

[Edited on 21-2-2013 by robertstar]

Magpie - 20-2-2013 at 17:15

Quote: Originally posted by robertstar

The problem is that even just a drop of the silver nitrate solution becomes the solution turbid. For turbid I mean it ceases to be transparent, assuming a brownish.

I think this is because you have no (or very little) cyanide.

Here's a picture of what the endpoint looks like for a cyanate titration w/AgNO3. IIRC that for the cyanide titration is very similar.

endpoint 2.JPG-thumb.jpg - 6kB

Quote: Originally posted by robertstar

I believe that my product is mostly sodium carbonate.
You know some form of separating the sodium cyanide from sodium carbonate without involving distillation?

You are probably right. The best yield that I got was 36.7%. I didn't attempt to purify it as my application did not require that.

To purify it you would likely have to first convert it to HCN. I took pains in my preparation not to mess with that bad boy.

robertstar - 21-2-2013 at 01:59

Thank you very much Magpie.

robertstar - 18-3-2013 at 15:34

I tried to produce sodium cyanide by heating sodium carbonate and urea as I reported behind.
Due to the strong odor of HCN exalate from the product, I believed that he had got a product with a purity appreciable.
But a titration with silver nitrate, showed me I got a negligible amount of cyanide.
I'm reporting my failure to alert anyone who tries to use the same method.

[Edited on 18-3-2013 by robertstar]

testimento - 2-7-2013 at 18:55

Ok, so far we have the following reactions:

NaCO3+Fe3O4+C+N2+hell of a heat = Ferrocyanide

Chloroform + ammonia distilled through 300C glass tube = ammonium cyanide and hydrochloric acid (shouldnt the NH4CN react with HCL to form NH4CL and HCN?)

sodium metal + molten urea or zinc(oxide) + molten urea = cyanides? could this work with lead oxide?

And then this:

http://www.sciencemadness.org/talk/viewthread.php?tid=14267

The making of calcium cyanamide from calcium oxide(caco3+hell of a heat) and molten urea = calcium cyanate + 700-900C = calcium cyanamide?

This article states that cyanamide will form hydrogen cyandie in alkali environment. I have understood that one will need acid to liberate the HCN, not alkali.

- WHAT CYANIDES (CYANATE, CYANAMIDE, CYANIDE?) can be used to form HCN gas upon reaction with acid or alkali?

What is the easiest way to make hydrogen cyanide gas(only to be intercepted in a solution of NaOH in EtOH to form suitable pure NaCN) with NO cyanide compounds of any kind available, only urea(as ammonia) and other common chemicals that can be made?

From my point of view, the cyanamide process and the chloroform+ammonia sounds most feasible, and I dont know would the Bucher(of whatever) process with C+Fe+N2+NaCO work, but anyways.

[Edited on 3-7-2013 by testimento]

Random - 2-7-2013 at 19:14

Quote: Originally posted by testimento

Ok, so far we have the following reactions:

NaCO3+Fe3O4+C+N2+hell of a heat = Ferrocyanide

I have always wondered if we could use a better nitrogen source like urea, which would decompose to biuret and ammonia, then leave biuret and it's decomoposition products as a source of nitrogen at high temperatures. It would be more reliable, safe and easier than stiring to use N2 from air. I have read somewhere I think they used animal parts like hair and leather as a nitrogen source for ferrocyanide production, but haven't found the actual procedure.

On another note, is the reaction fairly safe? Does it produce any cyanide at all? I would love to try it in the future but don't wanna fool myself and get like 30% cyanide along ferrocyanide.

testimento - 3-7-2013 at 04:42

I could try it. I have a place and equipment(steel reactors and industrial grade protective gear), but I lack the urea which I got to find in small quantity first. Originally I planned to use an air pump to inject atmospheric air into the container and, if necessary, use excess of carbon since oxygen would scavenge it.

I have the following formula:

-1kg C powder
-1kg NaCO3
-500g Fe2O3

I could try like 500 grams of urea with this mix and see what happens. My goal is to acquire sodium ferrocyanide which I will directly use for production of hydrogen cyanide gas with acid(HCl, citric, etc.) and inject it into solution of KOH in EtOH. I need to recover the iron from the remnants.

The next promising subject is molten urea + calcium oxide, which is expected to produce calcium cyanate and burned in high temp to get corresponding cyanamide and then release the HCN with acid. I have understood that HCN cannot be obtained from cyanate so cyanamide needs to be manufactured first.

[Edited on 3-7-2013 by testimento]

math - 12-7-2013 at 09:28

I've got a question about the preparation of sodium cyanide from cyanuric acid, NaHCO3 and charcoal.

From what I've read in this thread, things should go like that (starting from available compounds):

[A] 3 HCl (l) + C3Cl3N3O3 (s) ---> [C(O)NH]3 (s) + 6 Cl (g)

[B] 2 NaHCO3 + heat ---> Na2CO3 (s) + H2O (g) + CO2 (g)

Then

[C] Na2CO3 (s) + 2/3 [C(O)NH]3 ---> 2 NaOCN + CO2 + H2O

[D] NaOCN (s) + C (s) ---> NaCN (s) + CO (g)

At which temperature are reaction [B], [C] and [D] carried out? Can I expect to reach them on charcoal fire?

Do I need any catalyst for [C] or [D] to occur? Can I carry them in a porcelain/ceramic crucible? Do I need to use a specialty sealing crucible with two lids (one nested on top of each other) or would this be counterproductive?

Thank you

testimento - 21-7-2013 at 05:09

I could expect that the reaction temperature for the carbonic reduction is about 550C, which is the melting point of the sodium cyanate. The decomposition point is not cited, but its boiling point says it decomposes so the reaction should take place immediately upon melting.

The reaction is supposedly possible to carry out in ceramic crucible (porcelain, flower pot?).

Im gonna try this out. Cyanuric acid can be made from urea by heating it up to 175C and saving the ammonia from it and the rest can be done as previous poster said.

[Edited on 21-7-2013 by testimento]

S.C. Wack - 21-7-2013 at 15:37

Quote: Originally posted by S.C. Wack

So anyways as some have found, the distillation from H2SO4 is less than theoretical.

Some have found otherwise. I was speaking of the usual methods in the manuals.
http://www.sciencemadness.org/talk/viewthread.php?tid=9543&a...

BTW preparation of HCN or CO from cyanide, more convenient than formic acid if you have cyanide or live in a gold mining area...
Preparation of dry hydrogen cyanide and carbon monoxide
John Wade and Laurence C. Panting
J. Chem. Soc., Trans., 1898,73, 255-258

testimento - 6-11-2013 at 10:56

How can I test is the white solid a cyanide or a cyanate salt? I'm pretty sure it's cyanide but I would like to make sure.

I have safety solution made of little bit of sodium hydroxide and a scoop of calcium hypochlorite. The residual matters, like filtrate garbage, flasks and other stuff will make bubbles and hiss so they make a reaction in there, could this be an indicator that the stuff is really cyanide?

[Edited on 6-11-2013 by testimento]

Magpie - 6-11-2013 at 14:55

see:

http://www.sciencemadness.org/talk/viewthread.php?tid=9128&a...

Panache - 18-12-2013 at 02:43

In relation to the reaction between chloroform, ammonia and potassium hydroxide, Gatterman (1937, see Sci Mad Library for download) refers specifically to it. Interestingly i only just opened and read this thread in order to query with members the voracity of this claim, so it was pleasant to note the post referring generally to chlorinated methanes reacting with ammonia and hydroxides. I feel that if gatterman specifically referred to chloroform and KOH, there is an inherent implication that this is the best combination.

charmander - 26-12-2013 at 12:18

Hello. I have been following this forum for a few years now; just a lurker, but I would like some input from the more educated members. I have taken a few chemistry classes, just finished orgo 1, so I know a little bit but not enough.
I've done Polverone synthesis of cyanide using sodium carbonate, cyanuric acid and charcoal. Everything went well and I have attained a product. The crystals resemble sugar with a slightly tint of grey from the charcoal that slipped through the filters. The solution is very slippery much more than sodium carbonate. But I need relatively pure cyanide and I’d like input on how to achieve it.
I will react the product with an acid and distill the hydrogen cyanide and hydrogen cyanate (Isocyanic acid). I have a respirator and this will be done outside. This will remove charcoal and any sodium carbonate that was potently left, as well as any other byproducts, but not the cyanate.
The salts and acids of cyanide and cyanate have very similar properties. The solubility in alcohols and other solvents are really close. One noticeable difference was the melting points of HNCO and HCN, -86 °C and -14°C respectively.
Would taking HNCO and HCN in a RBF and putting it over a freezing saturated brine solution cause the HCN to crystallize out?
Or does anyone have a better idea on have to separate cyanates from cyanides?
I was thinking of forming a cyanide complex and separating that way, I need to look into this a bit more. HNCO also turns into cyanuric acid at high temps which is insoluble in water, but HCN probably will also polymerize to an extent and I REALLY hate even thinking about dealing with HCN as a gas.

Magpie - 26-12-2013 at 21:25

Take a read of the following, available through Google Books:

Allen’s Commercial Organic Analysis, vol VII

There's some information on treating with AgNO3 that will ppt out the cyanate but not the cyanide. It's in the chapter on Cyanogen.

charmander - 4-1-2014 at 19:35

Magpie, I read the section on cyanogens but I could not find the section on purifying cyanide. Maybe Google didn’t let me see all the pages. But I think I figured it out. Here is the plan.
Obtain sodium cyanide and sodium cyanate by reacting the crude mixture obtained with Polverone cyanuric acid method with sulfuric acid and condensing the gasses. Take the liquid hydrogen cyanide and hydrogen cyanate and pour it into ice cold solution of NaOH in denatured alcohol. The sodium cyanide and sodium cyanate salts will precipitate out. Wash the crystals with cold ethanol.
Make a saturated solution of the cyanogens salts. Then add drop wise silver nitrate until all the silver cyanate precipitates out. Filter out the silver cyanate.
The sodium cyanide solution will now contain NaNO3. NaNO3 is soluble in water and alcohol. So when adding denatured alcohol to the solution, only sodium cyanide should precipitate out. The product should be pure sodium cyanide.
Now to recover the silver from the silver cyanate, add nitric acid to the solution. According to Wikipedia this should yield silver nitrate, carbon dioxide and, ammonium nitrate. The silver could be recovered by heating the mixture and letting the salts decompose. Or ether could be used to dissolve the silver nitrate and not the ammonium nitrate. Ether is kind of hard to get so what other solvent or procedure can be used to recover the silver.
I just received my order of silver so I’ll try this procedure sometime soon and post the results.

Magpie - 4-1-2014 at 19:55

Quote: Originally posted by charmander

Magpie, I read the section on cyanogens but I could not find the section on purifying cyanide. Maybe Google didn’t let me see all the pages. But I think I figured it out. Here is the plan.

I think that is what I hoped you would do, ie, figure out a plan from reading the Allen book. I don't recall there being a specific procedure for separating the cyanate from cyanide.

I presume you have read my procedure in pre-pub for assaying cyanate. This may prove helpful.

Others can best advise you for recovering the silver. I have not done this yet.

Please be very careful handling cyanide. I have never handled HCN, only KCN. A good fume hood, outside work, and keeping the cyanide basic (whenever possible) are my recommendations.

charmander - 22-1-2014 at 20:36

So I did some more research and I found the article on detecting cyanate with cobalt(2). It was in the Allen's Commercial Organic Analysis volume 7. I guess last time I must have read in the wrong volume because this one is amazing, the older version or what ever I read had very little on cyanogens. I downloaded a pdf version so that i can have it for life

I had to make nitric acid at home so it took longer than usual to get the silver nitrate. The silver nitrate is in a 100ml solution and because of the weather it has been taking forever to evaporate.
Heating the silver nitrate solution caused silver oxide and or silver metal to precipitate out so it looks like this might take a while to evaporate.
But this weather might be a good thing. If it stays cold then the hydrogen cyanide and cyanate should stay as a liquid, which is REAL good.

testimento - 23-1-2014 at 02:22

Does NaCN/HCN react with aluminium? I stored a portion of it outside overnight and the aluminium foil I placed to cover the pot had been eaten away, literally corroded. I thought this could be some sort of HCN amalgation?

charmander - 23-1-2014 at 12:57

NaCN will react with aluminum and many other metals like gold and copper(which is why it is used in mining). HCN will not. HCN is usually stored in aluminum tanks.
You should not store your cyanide salts in metal containers or in glass jars with metal lids.
I store mine in a glass jar with a HDPE cap, and then this is put in a plastic bag for easy and safe clean up just in case it fall and breaks.
Please be safe.

DraconicAcid - 23-1-2014 at 13:46

Quote: Originally posted by testimento

Does NaCN/HCN react with aluminium? I stored a portion of it outside overnight and the aluminium foil I placed to cover the pot had been eaten away, literally corroded. I thought this could be some sort of HCN amalgation?

It's not amalgamation, it's literally corroded. Strong bases will react with aluminum, due to the formation of aluminates.

2 NaCN + 2 Al + 8 H₂O -> 2 NaAl(OH)₄ + 3H₂ + 2 HCN(g).

charmander - 5-3-2014 at 15:34

I need advice. So while I was waiting for my silver nitrate to dry off, (Btw it took over a month for 150ml of water to evaporate and leave crystals of silver nitrate. This must have been because of silver nitrate high solubility as well as the residual nitric acid left behind.) I tried making cyanide from potassium ferricyanide. (Notice ferri not ferro). I attempted to make it this way before without success, but after getting some lab experience with nitrated products I attempted the experiment again. I reacted 20 grams of potassium ferricyanide and 15 ml of about 70% sulfuric acid. I distilled over about 7 ml of a clear liquid which should be hydrogen cyanide. With a dropper I transfer some of this to a solution of denatured ethanol and sodium hydroxide. What should have happened was the sodium cyanide should have precipitated out, but something else took place. On the top of the ethanol solution an oily layer formed that took on an orangeish red color. After giving it a few swirls the layer dissolved into the ethanol solution giving the whole solution an orange color. There was no precipitant.
In another beaker I added the hydrogen cyanide to a solution of sodium hydroxide in water. There was a small color change and the hydrogen cyanide seemed to dissolve into the solution. I then poured ethanol into the beaker but nothing precipitated. The solution then turned into the same orange red color.
In a third beaker I dripped the hydrogen cyanide into distilled water. As each drop hit the water gas evolved from that area. The solution turned slightly orange.
Being disappointed I took a 30 minute break. I left the sealed flask with the hydrogen cyanide in an ice bath. I come back and the hydrogen cyanide turned a dark red/black color. I poured this into vial and sealed it to deal with it the next day. It was dark and I had to clean up.
The next day I look at the product and it solidified into a black solid cake. After I opened it I took a whiff and it was not a pleasant scent. Some of the cake dried up on top into a light brown powder.
So I definitely formed hydrogen cyanide but it polymerized up. Can someone give my some advice on how to obtain the cyanide salt and prevent it from polymerizing?

Oscilllator - 5-3-2014 at 16:28

Charmander read through this thread. The posts by Zan Divine contain the information looking for. In future, be sure to look through the thread to see if your question has already been answered.

Also, sniffing jars of hydrogen cyanide is an extremely good way to get a darwin award.

charmander - 5-3-2014 at 16:52

I read it before, i guess i got to read it all over again.
I took a whiff about a foot and a half away from the jar after the used my hand to move the vapors towards me. My chem professor thought me that. It seems safe enough for me.

AJKOER - 14-3-2014 at 10:22

Quote: Originally posted by AJKOER

A simple direct and proven approach (but gaseous requiring precautions and use of an expensive catalyst), try to replicate the industrial Andrussow process either on a micro scale or larger. Per Wiki, to quote:

"The Andrussow process is an industrial process for the production of hydrogen cyanide from methane and ammonia in the presence of oxygen and a platinum catalyst.[1][2]

CH4 + NH3 + 1.5 O2 → HCN + 3 H2O

.....

What I find interesting in the above reaction is it similarity to the Ostwald process for the production of NO also employing a platinum catalyst. This observation was also noted by the author of my previously cited doctoral thesis (see page 5 at http://research.cems.umn.edu/schmidt/schmidtpapers/thesis/Sa... ). So what if NO formation provides a path to HCN creation? Assuming it is, in the home lab, one can easily replace this step (and the use of a Pt catalyst) with just supplying a stream of NO to the combustion of an appropriate hydrocarbon.

There is some support for this method based on research of removing NO waste gas by "reburning". See "NITROGEN OXIDE REBURNING WITH HYDROCARBON FUELS", by Thomas E. Burch at https://web.anl.gov/PCS/acsfuel/preprint%20archive/Files/35_... . The author outlines the reaction mechanism as follows:

"Employing the mechanisms and senstivity analysis of Miller and Bowman (1989) along with calculations
conducted by Chen et al. (1989) it seems resonable to view reburning as possessing two major kinetic barriers. The first
barrier is the conversion of NO to HCN by combination with various hydrocarbon fragments such as

C + NO -> CN + O
CH + NO -> HCN + O
CH2 + NO -> HCNO + H

The accepted rate constants for these reactions are all within roughly one order of magnitude so the dominant
mechanism in the conversion of NO to HCN is strongly dependent on the relative concentrations of the reducing species produced. Regardless of which mechanism dominates, there is general agreement that the end product is HCN, whether formed directly of by rapid conversion of intermediates such as CN.

The second major kinetic obstacle appears to be oxidation of HCN via one of the following reactions:

HCN + OH -> HOCN + H
HCN + OH -> HNCO + H
HCN + O -> NCO + H
HCN+O -> NH + CO

Having accomplished this step the subsequent conversion to N atoms is rapid. N atoms are then recycled to
form NO or react with NO to form N2.
Using this two barrier concept many of the salient feactures of reburning can be interpreted."

The author also makes favorable comments suggesting the use of benzene in place of methane.

I am still thinking over exactly how to implement the underlying process, but I thought it was interesting enough to present. One embodiment, for example, could be based on the ability of Nitric oxide to support and enhance combustion. So, perhaps placing burning benzene in an atmosphere of pure NO in a closed vessel would form HCN. Addressing/limiting impurities would be an issue.
--------------------------------------------------------

A comment of preparing cyanide from cyanogen, per Atomistry.com on cyanogen to quote (link: http://www.google.com/url?sa=t&rct=j&q=atomistry.com... ):

"[Water] dissolves about four and a half times its volume of cyanogen gas, alcohol about twenty-three times its volume. Water, however, acts chemically on cyanogen, causing the separation of a brown insoluble substance known as azulmic acid, and at the same time hydrolysing the cyanogen (NC-CN), producing from it oxamide (H2NOC-CONH2), oxamic acid (HOOC-CONH2), oxalic acid (HOOC-COOH), and their ammonium salts; together with the following compounds containing only one carbon atom: hydrocyanic acid, urea (H2N-CO-NH2), and ammonium carbonate. When cyanogen is passed into water at 0° C., however, the reaction is simple, hydrocyanic and cyanic acids being formed thus:

(CN)2 + H2O = HCN + HCNO. "
--------------------------------------------

Also, per Atomistry.com CNCl does not decompose in water as was previously indicated.

[Edited on 14-3-2014 by AJKOER]

Nitrous2000 - 1-10-2014 at 10:28

Quote: Originally posted by charmander

I read it before, i guess i got to read it all over again.
I took a whiff about a foot and a half away from the jar after the used my hand to move the vapors towards me. My chem professor thought me that. It seems safe enough for me.

Can YOU smell cyanide gas?

AJKOER - 3-10-2014 at 14:56

OK, I an across a preparation path using available, mostly households, starting materials. To quote from Atomistry.com on HCN (link: http://carbon.atomistry.com/hydrocyanic_acid.html ):

"Bergmann has shown that when ammonia is passed over carbon heated to about 1300° C., 90 per cent, of it is converted into HCN. The reaction is endothermic, its heat being -39,500 calories. A modification of this reaction is that of Roeder and Grunwald, who pass a mixture of ammonia, and nitrous oxide over heated carbon, the reaction being:

2NH3 + N2O + 4C = 4HCN + H2O - 58,000 calories.

Owing to the heat of decomposition of nitrous oxide, which is endothermic, and the heat of formation of steam, it is not necessary to heat the carbon to so high a temperature as in the former case; indeed the yield of hydrogen cyanide is nearly quantitative when the temperature of the carbon is but 450° C. "

As I have recently purchased N2O and can dispense a stream of gas using the Nitrous oxide whipper, one possible embodiment would be as follows:

1. Place aqueous ammonia in a whipper and infuse with N2O via a 8 gram cartridge.

2. From a charcoal grill, place hot coals in a pipe.

3. Direct and release the N2O/NH3 gas from the whipper through the pipe.

4. Direct the exit gases from the pipe containing HCN into a solution of NaOH.

Points to be resolved:

1. On the chemistry, is water vapor in the gas mix an issue (and a drying step would be required).

2. Do the coals have to be continually heated while in the pipe.

3. Forming a seal with the exit nozzle from the whipper onto the pipe may be a problem.
-------------------------------

A more limited but even easier embodiment (but not necessarily safer) would be to heat outdoors Carbon, Ammonia and N2O in an expandable container in a microwave for multiple short burst, followed by cooling, to avoid containment rupture. Note, allowing for gaseous expansion favors increase yield (the formation equation indicates that 3 moles of gas become 4, and there could also be some N2O decomposition where 2 moles become 3, which is accompanied by a loud knock like noise) and reduced risk of rupture.

Finally, add NaOH upon completion for NaCN in minutes (or possible death, if one is not performing this experiment as recommended, or indoors without a gas mask and a cyanide antidote kit).

This is probably also a good reason to avoid thus experimenting with N2O and compounds rich in Carbon, Hydrogen and/or Nitrogen, and then expecting something possibly not too lethal.

[Edit] Do not attempt to make this a one pot synthesis and heat NaOH (or, Na2CO3 plus water vapor) in an atmosphere of N2O in a microwave. As I have noted previously on SM, this could produce quite a fireworks display with potential containment breach. See discussion at http://www.sciencemadness.org/talk/viewthread.php?tid=32334#... and references cited there in. Also I suspect, ignoring safety and feasibility issues, that only an impure NaCN could be so formed.

[Edited on 4-10-2014 by AJKOER]

Dan Vizine - 9-10-2014 at 09:06

Quote: Originally posted by charmander

I REALLY hate even thinking about dealing with HCN as a gas.

Hi Charmander,

My advice is don't think of it as a gas. Think of it as a volatile liquid.

The gas phase is just a fleeting moment, it turns to liquid very easily with circulating ice water. Besides, you need the gas phase, it's the only practical method that doesn't incur huge losses.

Here is a critical point that I know to be true, but the reason mystifies me:
If you collect the HCN as it distills out of the ferricyanide/acid pot, it stays water clear. If you then add it to stirred aqueous NaOH, you get a clear solution of NaCN. However, if you lead the condensed HCN from the reaction directly into stirred, aqueous base it will turn very, very dark and quickly. It's clearly a polymerization issue of some kind. Offhand, the two processes don't seem all that different, but they clearly are.

One other point. HCN is an endothermic compound and as such, may decompose spontaneously (ESPECIALLY if contaminated with cyanide anions*). This is prevented by addition of a small amount of H2SO4. I think I give a recommended level in my earlier posts. it's a per cent or two, roughly. I add it to the collection flask before the reaction even begins. Keep the flask at 0 C.

* Your glassware must not have any basic residues left in it!

[Edited on 9-10-2014 by Dan Vizine]

Dr.Arz - 18-10-2014 at 21:48

What kind of protective measures you use when you work with cyanides? I have read that some people here actually dont even have any face gear or ventilation and some have even sniffed HCN flasks.

So am I just too paranoid about toxicity of cyanides or what? I have been thinking how can I handle them safely without slightest risk of harming myself or others. Only really safe thing is to make a fume hood outdoors, put a large duct fan on top of it and add a long, at least 2-3 meters chimney from pvc tube that will suck everything out from the hood up to the sky. Still after this I want to wear high grade respirator mask, long nitrile gloves and maybe even full body pp suit just in case. Also to keep hypochlorite liquid near to rinse and wash all parts that were in contact with any cyanides and discard all wastewater carefully. Im afraid draining them to sewer because gases can absorb to floor drain water locks and evaporate insides. Problems that its getting really cold outsides so I got to either wait for summer or then figure out some safe way. My worst nightmare is that any of the distilling equipment implode or fall apart during vacuum distillations, even I use only top grade new-bought glass and extra precautions with applying heat and cold or any stresses on them, it is just too much of thinking hundreds of grams of cyanides bursting into a cloud of aerosol.

[Edited on 19-10-2014 by Dr.Arz]

careysub - 19-10-2014 at 07:45

Quote: Originally posted by Dan Vizine

...

Here is a critical point that I know to be true, but the reason mystifies me:
If you collect the HCN as it distills out of the ferricyanide/acid pot, it stays water clear. If you then add it to stirred aqueous NaOH, you get a clear solution of NaCN. However, if you lead the condensed HCN from the reaction directly into stirred, aqueous base it will turn very, very dark and quickly. It's clearly a polymerization issue of some kind. Offhand, the two processes don't seem all that different, but they clearly are.
...

[Edited on 9-10-2014 by Dan Vizine]

I did not know this would happen - but I can postulate what is probably going on.

HCN polymerizes in the presence of bases, a process that is autocatalytic, but not (initially) a very high rate reaction.

When the HCN is being condensed into NaOH solution it is being very slowly added to a huge excess of base, and has time for the polymerization process to start, and once it has commenced very far you are toast.

When you add a mass of liquid HCN all at once to NaOH solution there is never an excess of base, and the NaOH is neutralized immediately.

The Russians stabilized their HCN rocket warheads with phosphoric acid, so that alkaline conditions were never encountered.

careysub - 19-10-2014 at 08:42

Quote:

What kind of protective measures you use when you work with cyanides? I have read that some people here actually dont even have any face gear or ventilation and some have even sniffed HCN flasks.

So am I just too paranoid about toxicity of cyanides or what?

HCN is very poisonous to be sure, if absorbed by the body all at once 25 mg - basically one drop - can be fatal. The worst aspect of cyanide poisoning, should it occur, is that is extremely fast. You would be unable to help yourself. (Because of the way it works cyanide is probably the fastest poison there is.)

That said - it is unique among strong poisons in that it is not only NOT CUMULATIVE, your body has a detoxification mechanism built in so that sufficiently low exposure rates are actually harmless. Cyanide is widely distributed in plants in low concentrations, and mammals evolved the ability to destroy it.

The detoxification rate is about 0.07 mg per minute per kilogram of body weight. if you weight 70 kg you can absorb 5 mg a minute continuously without suffering any ill effect (don't test this - it is a safety feature, not a challenge). The 25 mg LD given above requires breathing a high vapor concentration so that the entire dose is absorbed in a minute or less (e.g. 2.5 grams evaporated in a cubic meter of air).

HCN is detectable in air at a threshold concentration of about 0.7 mg/M^3. But people vary in sensitivity, some people don't detect it well, and people quickly become desensitized to the odor. Concentrations of up to 40 mg/M^3 can be tolerated indefinitely, but four times this will kill you in half an hour, five times will kill you in ten minutes.

Don't smell an HCN flask. Ever.

If you want to find out what HCN smells like I suggest putting a drop (~40 mg) in a liter of water and smelling that. No toxic exposure is possible in that situation.

Quote:

I have been thinking how can I handle them safely without slightest risk of harming myself or others. Only really safe thing is to make a fume hood outdoors, put a large duct fan on top of it and add a long, at least 2-3 meters chimney from pvc tube that will suck everything out from the hood up to the sky. Still after this I want to wear high grade respirator mask, long nitrile gloves and maybe even full body pp suit just in case. Also to keep hypochlorite liquid near to rinse and wash all parts that were in contact with any cyanides and discard all wastewater carefully. Im afraid draining them to sewer because gases can absorb to floor drain water locks and evaporate insides. Problems that its getting really cold outsides so I got to either wait for summer or then figure out some safe way.

Get a chemical respirator (half-mask is fine) with either a general purpose or acid gas cartridge. Others are not suitable.

Wear good chemical gloves.

Have a basin of 0.5% hypochlorite solution (household bleach diluted 10:1) at the ready at all times, with the plan of dunking all of your equipment in it when you are done. This will completely destroy all cyanide immediately.

A PP (Tyvek) suit is a good idea when working with any caustic material, if only to protect your clothes.

I think the chimney thing is unnecessary if working outdoors, but I would use some forced air circulation scheme (a fan and a box) to ensure air flows away from you.

Quote:

My worst nightmare is that any of the distilling equipment implode or fall apart during vacuum distillations, even I use only top grade new-bought glass and extra precautions with applying heat and cold or any stresses on them, it is just too much of thinking hundreds of grams of cyanides bursting into a cloud of aerosol.

Design your experiments appropriately. Don't do vacuum distillations with hundreds of grams of cyanide, for example.

[Edited on 19-10-2014 by careysub]

Dan Vizine - 19-10-2014 at 09:24

When you add a mass of liquid HCN all at once to NaOH solution there is never an excess of base, and the NaOH is neutralized immediately.

Ah, but the answer isn't that simple. I always add the liquid cyanide (previously collected) in a dropwise fashion to cold, stirred base. The process takes at least 45 - 60 min for 100 g of HCN (to avoid exotherms which may boil off some HCN).

It is very similar to the dropwise distillation to cold, stirred base straight from the condenser, which causes darkening quite quickly.

careysub - 19-10-2014 at 09:40

Quote: Originally posted by Dan Vizine

When you add a mass of liquid HCN all at once to NaOH solution there is never an excess of base, and the NaOH is neutralized immediately.

Do you add any stabilization acid to the distillation flask or product afterward?

[Edited on 19-10-2014 by careysub]

careysub - 20-10-2014 at 03:57

It would be very interesting to get hold of this article (in English translation):
Völker, T. 1960. Polymeric hydrogen cyanide. Angew. Chemic 72, 379–384.

It seems to be the principal reference on the subject from the perspective of preparative and industrial chemistry.

Dan Vizine - 21-10-2014 at 15:33

Quote: Originally posted by Dan Vizine