Mercury(II) fulminate

Mercury(II) fulminate
Other names Fulminated Mercury
Identifiers
CAS number	628-86-4 Y
PubChem	11022444
ChemSpider	9197626 Y
ChEBI	CHEBI:39152 Y
Jmol-3D images	Image 1
SMILES [O-][N+]#C[Hg]C#[N+][O-]
InChI InChI=1S/2CNO.Hg/c2*1-2-3; Y Key: MHWLNQBTOIYJJP-UHFFFAOYSA-N Y InChI=1/2CNO.Hg/c2*1-2-3;/rC2HgN2O2/c6-4-1-3-2-5-7 Key: MHWLNQBTOIYJJP-HZIBCBEIAJ
Properties
Molecular formula	Hg(CNO)2
Molar mass	284.624 g/mol
Appearance	Grey Crystalline solid
Density	4.43 g/cm3
Solubility in water	slightly soluble
Solubility	soluble in ethanol, ammonia
Explosive data
Shock sensitivity	High
Friction sensitivity	High
Explosive velocity	4250 m/s
Hazards
Main hazards	Highly Toxic, Shock Sensitive Explosive
Autoignition temperature	180 °C
Y (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Mercury(II) fulminate, or Hg(CNO)₂, is a primary explosive. It is highly sensitive to friction and shock. It is mainly used as a trigger for other explosives in percussion caps and blasting caps. Mercury(II) cyanate, though its formula is identical, has a different atomic arrangement; the cyanate and fulminate anions are isomers.

First used as a priming composition in small copper caps after the 1830s, mercury fulminate quickly replaced flints as a means to ignite black powder charges in muzzle loading firearms. Later, during the late 19th century and most of the 20th century, mercury fulminate or potassium chlorate became widely used in primers for self-contained rifle and pistol ammunition. Mercury fulminate has the distinct advantage over potassium chlorate of being non-corrosive, but it is known to weaken with time. Today, mercury fulminate has been replaced in primers by more efficient chemical substances. Those are non-corrosive, less toxic and more stable over time: lead azide, lead styphnate and tetrazene derivatives. In addition, none of these compounds replacing Hg(II) fulminate requires mercury for manufacture, supplies of which can be unreliable in wartime.^{[citation needed]}

Preparation

Mercury(II) fulminate is prepared by dissolving mercury in nitric acid and adding ethanol to the solution. It was first prepared by Edward Charles Howard in 1800. The crystal structure of this compound was only determined in 2007.

Silver fulminate can be prepared in a similar way, but this salt is even more unstable than mercury fulminate; it can even explode under water.

In Popular Culture

On AMC's Breaking Bad, Walter White uses fulminated mercury to cause an explosion at Tuco Salamanca's hangout.

External links

• National Pollutant Inventory - Mercury and compounds Fact Sheet
• "300 years after discovery, structure of mercury fulminate finally determined". physorg.com. 24 August 2007. http://www.physorg.com/news107176552.html.