Some Possibly Dangerous Chemical Interactions

[Tub Buster]

I'm posting a few of these for discussion....

1. Cyanide. The ancient method of producing cyanide was to fuse potash (potassium carbonate) with iron oxide and proteinaceous or nitrogenous materials (sources of nitrogen e.g., blood, fecal matter, etc.). This produced potassium ferrocyanide, which was treated with more potash to form potassium cyanide.

Notice that this procedure is similar to fluxing a metal oxide with soda ash (sodium carbonate). If nitrogen is present, for example as nitre (sodium nitrate), we have the basic requirements for the formation of cyanide. The question being, can cyanide be formed in the presence of metals other than iron?

Another question, doesn't cyanide act as a reductant?

2. Urea.
Nitric acid + urea -> Urea nitrate (heat of explosion: 767 kcal/kg = 3211 kJ/kg; deflagration point: 186 deg C)

Urea nitrate + sulfuric acid -> nitro urea (heat of explosion: 895 kcal/kg = 3745 kJ/kg; beginning of decomposition: 80 deg C)

This is what you're making when you add urea to aqua regia, and then add sulfuric acid.

3. Silver oxalate. Ag2C2O4. Explodes around 110 - 130 deg C. See Urbanski, p. 224.

4. Complex salts of precious metals. The quote below is from:

Chemistry and Technology of Explosives
by TADEUSZ URBANSKI, 1964
Library of Congress Card. No. 63-10077
(p. 230, vol 3)

The complex salts of precious metals, formed by the action of ammonia either on aqueous solutions of silver, gold and platinum salts or on silver oxide were the first substances to reveal the ability to explode violently on heating, on direct contact with, flame or by friction or impact (“fulminating” silver and gold).

Later it was found that a number of other metals which can give typical complex salts (Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni and Zn) can form explosive coordination compounds.

These substances have a variable composition depending upon the reaction conditions, chiefly the concentration of the reagents used. ... The explosive properties of these salts were partially studied by Ephraim and Jahnsen [120] and were later investigated in detail by Friedrich and Vervoorst [121]. The latter also investigated the analogous combinations described by Franzen and Mayer [122], in which ammonia was replaced by hydrazine.

120. F. EPHIRAIM and A. JAHNSEN. Ber. 48, 41 (1915).
121. W. FRIEDRICH and P. VERVOORST, Z. ges. Schiess- u. Sprengstoffw. 21, 49 (1926),
122. H. FRANZEN and O. V. MAYER, Z. anorg. Chem. 60, 247 (1908); 70, 145 (1911).

If anyone has access to Science Citation Index, you can see who has cited those references, and that will point you to more modern articles.

The azides are poisonous as well as explosive. Mixing with acid liberates hydrazoic acid, a poison gas which can have delayed effects. Silver azide is photosensitive - ultraviolet radiation makes it detonate, and gold powder makes it more sensitive.

To destroy azides, mix with vinegar in which sodium nitrite was dissolved (Urbanski, p. 171).

 

[rickbb]

From a safety point it's important to know what not to do, and in this respect this is a good post.

However;

Perhaps we shouldn't "help" anyone to discover just how explosives and poison gases are made by pointing these things our.

 

[solar_plasma]

Perhaps we shouldn't "help" anyone to discover just how explosives and poison gases are made by pointing these things our.

A good point. On the other side, just mixing Au, AR and SMB makes no shiny gold button. Same here, reading 5 lines about those compounds will not give anyone the expertise to form them intentionally. It is good to know, where the dangers hide and more is not been published in this post.

 

[Pantherlikher]

Having delt with ADD, Attention Deficate Dissorder all my life from me as well as kids.
I am very inclined to NOT completely explain how to make dangerous mixtures and only state that it can be extremely dangerous to mix haphazzardly.

In reading the post, I got sidetrackd and interested in what and how to do it.
Years ago before finding the forum, I spent over a year digging into refinning and found myself having to stop after I found myself learning about the "H" bomb as well as nukes...

It's tough enough staying focused on the goals at hand.

B.S.
...Squirrel!!!...

 

[niteliteone]

Having delt with ADD, Attention Deficate Dissorder all my life from me as well as kids.
I am very inclined to NOT completely explain how to make dangerous mixtures and only state that it can be extremely dangerous to mix haphazzardly.

In reading the post, I got sidetrackd and interested in what and how to do it.
Years ago before finding the forum, I spent over a year digging into refinning and found myself having to stop after I found myself learning about the "H" bomb as well as nukes...

It's tough enough staying focused on the goals at hand.

B.S.
...Squirrel!!!...

Rest assured, You're not alone with the ADD induced distractions :shock:

 

[Tub Buster]

Perhaps we shouldn't "help" anyone to discover just how explosives and poison gases are made by pointing these things our.

I spent some time re-wording the message before posting, to make it vague while delivering the necessary info. The only exception was urea, which is the exact process being used by refiners, so I didn't see any point in obfuscation.

 

[freechemist]

Some comments to discuss on the subject...

1.) Cyanide: The ancient method of producing cyanide used nitrogen and carbon containing materials as key-ingredients. An important prerequisite for such materials is the presence of one or more covalent carbon-nitrogen bonds, -C-N-, like in proteins, amino-acids, urea and the like, the nitrogen being mostly present in an oxidation-state of (-III). A combination of potash (potassium carbonate) and sodium- or potassium nitrate, where nitrogen is in it's highest oxidation state, (+V) never delivers any cyanide. Charcoal, mixed with nitrate (a strong oxidant) and varying amounts of sulfur are the components of ancient gun-powder. Chances are, that an ordinary barbeque-grill, where proteinaceous meat-juice is dripping down occasionally onto the glowing charcoal, is much more dangerous with respect to cyanide-formation, than any of our smelting-procedures.

2.) Urea: it's use in recovery/refining and it's possible dangers have been discussed already extensively in this forum.

3.) Silver oxalate, as far as I know, is never encountered in our usual recovery/refining procedures, because silver chloride, AgCl, is insoluble in aqueous HCl, and thus silver is separated by filtration before having a chance to come into contact with oxalic acid eventually. Silver oxalate is a colorless solid, practically insoluble in water, but will dissolve in aqueous solutions of strong acids, forming Ag⁺-ions and water-soluble oxalic acid.

4.) Complex salts of precious metals: The for us all known way, to refine palladium, involves an aqueous solution of tetrammine-palladium(II)chloride, [(NH₃)₄Pd]Cl₂, from which pure diammine-palladium(II)chloride, (NH3)₂PdCl₂ is crystallized. As far as I know, this procedure has never led to an explosion.

 

[Tub Buster]

Very thoughtful comments, Freechemist, thanks. Somehow I missed the previous comments on urea, I'll do some more searching.