Reverend Necroticus Rex - 24-8-2004 at 19:24
A while ago I discussed with one of the members (you know who you are
)
via PM regarding a thread on fulminate synthesis.
Here's my 0.2 on the matter
Fulminic acid is both toxic and unstable, decomposing spontaneously at 0 degrees C, the halogen cyanides decompose in aqueous solution to cyanic acid
and presumably the free halogen.
I am proposing an aqueous solution of a metal hydroxide to be treated with a halogen cyanide other than fluorine which would probably not decompose
due to fluorine's nasty tendency to gain a vicious hold upon whichever element that bonds (read is assaulted by ) to it.
How about treatment of an ice-cold NaOH solution with the halogen cyanide of choice, preferably ClCN as this would cause the formed Cl gas to exit
stage left immediately from the reaction vessel, forming fulminic acid in situ thus forming sodium fulminate.
NaCN+Cl2-CNCl+NaCl at PH 9-11
CnCl+2NaOH-NaClO+NaCl.
I think thius would be a novel way to prepare fulminates sans acids for the HNO3 imparied (me at the moment
)
Marvin - 25-8-2004 at 01:43
I think you are confusing cyanic acid with fulminic acid.
NCO is cyanate. CNO is fulminate.
Carbon wants the oxygen badly, and the nitrogen is blocking it in fulminate, so knock the nitrogen away (forms N2 gas) and carbon gets the oxygen.
This makes it a high energy state compaired to what it can decompose to.
Cyanate on the other hand, the carbon allready has the oxygen, so there is much less power to be gained when it decomposes, and its not explosive.
Cyanic acid decomposes rapidly above 0C, in fact it polymerises. Fulminic acid might not even be preperable as a free acid. It certainly cant be
made in concentrated solution.
ClCN undoubtly hydrolyses to cyanate, not fulminate.
Fulminate chemistry is... complicated. There are a lot of weird complexes that form when you think you should be getting simple salts. Its not a
good material for home experimenters. Quite aside from it being explosive of course.
JohnWW - 25-8-2004 at 02:13
And it is bloody poisonous, too, along with the NaCN and CNCl proposed to be used in the above reactions. You had better try it only in an
hermetically sealed chamber, perhaps a good "glovebox". And you had better wear a gas-mask and have some amyl nitrite (antidote for cyanide
poisoning) on hand.
John W.