Mercury(II) fulminate

Last updated
Mercury(II) fulminate
Mercury-fulminate-3D-vdW.png
Mercury-fulminate-xtal-3D-vdW.png
Mercuryfulminate puryfied.jpg
Names
IUPAC name
Mercury(II) fulminate
Systematic IUPAC name
Dioxycyanomercury
Other names
Fulminated Mercury
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.010.053 OOjs UI icon edit-ltr-progressive.svg
PubChem CID
UNII
  • InChI=1S/2CNO.Hg/c2*1-2-3; Yes check.svgY
    Key: MHWLNQBTOIYJJP-UHFFFAOYSA-N Yes check.svgY
  • InChI=1/2CNO.Hg/c2*1-2-3;/rC2HgN2O2/c6-4-1-3-2-5-7
    Key: MHWLNQBTOIYJJP-HZIBCBEIAJ
  • [O-][N+]#C[Hg]C#[N+][O-]
Properties
C2N2O2Hg
Molar mass 284.624 g/mol
AppearanceGrey, Pale Brown, or White Crystalline solid
Density 4.42 g/cm3
Melting point 160 °C (320 °F; 433 K)
Boiling point 356.6 °C (673.9 °F; 629.8 K)
slightly soluble
Solubility soluble in ethanol, ammonia
Explosive data
Shock sensitivity High
Friction sensitivity High
Detonation velocity 4250 m/s
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
Highly Toxic, Shock Sensitive Explosive
NFPA 704 (fire diamond)
NFPA 704.svgHealth 4: Very short exposure could cause death or major residual injury. E.g. VX gasFlammability 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g. canola oilInstability 4: Readily capable of detonation or explosive decomposition at normal temperatures and pressures. E.g. nitroglycerinSpecial hazards (white): no code
4
1
4
170 °C (338 °F; 443 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
X mark.svgN  verify  (what is  Yes check.svgYX mark.svgN ?)

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

Contents

First used as a priming composition in small copper caps beginning in the 1820s, 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 became widely used in primers for self-contained rifle and pistol ammunition; it was the only practical detonator for firing projectiles until the early 20th century. [1] Mercury fulminate has the distinct advantage over potassium chlorate of being non-corrosive, but it is known to weaken with time, by decomposing into its constituent elements. The reduced mercury which results forms amalgams with cartridge brass, weakening it, as well. Today, mercury fulminate has been replaced in primers by more efficient chemical substances. These are non-corrosive, less toxic, and more stable over time; they include lead azide, lead styphnate, and tetrazene derivatives. In addition, none of these compounds require mercury for manufacture, supplies of which can be unreliable in wartime.

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. [2] [1] The crystal structure of this compound was determined only in 2007. [3]

Silver fulminate can be prepared in a similar way, but this salt is even more unstable than mercury fulminate; it can explode even under water and is impossible to accumulate in large amounts because it detonates under its own weight. [4]

Decomposition

The thermal decomposition of mercury(II) fulminate can begin at temperatures as low as 100 °C, though it proceeds at a much higher rate with increasing temperature. [5]

A possible reaction for the decomposition of mercury(II) fulminate yields carbon dioxide gas, nitrogen gas, and a combination of relatively stable mercury salts.

4 Hg(CNO)2 → 2 CO2 + N2 + HgO + 3 Hg(OCN)CN
Hg(CNO)2 → 2 CO + N2 + Hg
Hg(CNO)2 → :Hg(OCN)2 (cyanate or / and isocyanate)
2 Hg(CNO)2 → 2 CO2 + N2 + Hg + Hg(CN)2 (mercury(II) cyanide)

In the episode "Crazy Handful of Nothin' " of the television series Breaking Bad , Walter White uses fulminated mercury "with a little tweak of chemistry" to create an explosion in meth kingpin Tuco Salamanca's office as an intimidation tactic. The depiction of the substance and its effects in the show is questionable in accuracy; the crystals themselves, as shown, would be too large to survive handling without exploding, and when Walt throws a crystal at the ground the resulting explosion ruins the office but leaves the occupants unharmed; [6] however, it is not explained what White means by a tweak of chemistry or how that may have affected the crystal's explosive properties.

See also

Related Research Articles

<span class="mw-page-title-main">Explosive</span> Substance that can explode

An explosive is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure. An explosive charge is a measured quantity of explosive material, which may either be composed solely of one ingredient or be a mixture containing at least two substances.

Carbon compounds are defined as chemical substances containing carbon. More compounds of carbon exist than any other chemical element except for hydrogen. Organic carbon compounds are far more numerous than inorganic carbon compounds. In general bonds of carbon with other elements are covalent bonds. Carbon is tetravalent but carbon free radicals and carbenes occur as short-lived intermediates. Ions of carbon are carbocations and carbanions are also short-lived. An important carbon property is catenation as the ability to form long carbon chains and rings.

Urea, also called carbamide, is an organic compound with chemical formula CO(NH2)2. This amide has two amino groups joined by a carbonyl functional group. It is thus the simplest amide of carbamic acid.

<span class="mw-page-title-main">Tetryl</span> Chemical compound

2,4,6-Trinitrophenylmethylnitramine or tetryl (C7H5N5O8) is an explosive compound used to make detonators and explosive booster charges.

<span class="mw-page-title-main">Detonator</span> Small explosive device used to trigger a larger explosion

A detonator, sometimes called a blasting cap in the US, is a small sensitive device used to provoke a larger, more powerful but relatively insensitive secondary explosive of an explosive device used in commercial mining, excavation, demolition, etc.

<span class="mw-page-title-main">Percussion cap</span> Ignition source in a type of firearm mechanism

The percussion cap, percussion primer, or caplock, introduced in the early 1820s, is a type of single-use percussion ignition device for muzzle loader firearm locks enabling them to fire reliably in any weather condition. Its invention gave rise to the caplock mechanism or percussion lock system which used percussion caps struck by the hammer to set off the gunpowder charge in rifles and cap and ball firearms. Any firearm using a caplock mechanism is a percussion gun. Any long gun with a cap-lock mechanism and rifled barrel is a percussion rifle. Cap and ball describes cap-lock firearms discharging a single bore-diameter spherical bullet with each shot.

In chemistry, azide is a linear, polyatomic anion with the formula N−3 and structure N=N+=N. It is the conjugate base of hydrazoic acid HN3. Organic azides are organic compounds with the formula RN3, containing the azide functional group. The dominant application of azides is as a propellant in air bags.

<span class="mw-page-title-main">Centerfire ammunition</span> Type of ammunition that is commonly found in small-, medium-, and large-caliber firearms

A center-fire is a type of firearm metallic cartridge whose primer is located at the center of the base of its casing. Unlike rimfire cartridges, the centerfire primer is typically a separate component seated into a recessed cavity in the case head and is replaceable by reloading the cartridge.

<span class="mw-page-title-main">Silver fulminate</span> High explosive used in bang snaps

Silver fulminate (AgCNO) is the highly explosive silver salt of fulminic acid.

Pseudohalogens are polyatomic analogues of halogens, whose chemistry, resembling that of the true halogens, allows them to substitute for halogens in several classes of chemical compounds. Pseudohalogens occur in pseudohalogen molecules, inorganic molecules of the general forms PsPs or Ps–X, such as cyanogen; pseudohalide anions, such as cyanide ion; inorganic acids, such as hydrogen cyanide; as ligands in coordination complexes, such as ferricyanide; and as functional groups in organic molecules, such as the nitrile group. Well-known pseudohalogen functional groups include cyanide, cyanate, thiocyanate, and azide.

<span class="mw-page-title-main">Fulminate</span> Chemical compounds containing an –O–N≡C group

Fulminates are chemical compounds which include the fulminate ion. The fulminate ion is a pseudohalic ion because its charge and reactivity are similar to those of the halogens. Due to the instability of the ion, fulminate salts are friction-sensitive explosives. The best known is mercury(II) fulminate, which has been used as a primary explosive in detonators. Fulminates can be formed from metals, such as silver and mercury, dissolved in nitric acid and reacted with ethanol. The weak single nitrogen-oxygen bond is responsible for their instability. Nitrogen very easily forms a stable triple bond to another nitrogen atom, forming nitrogen gas.

<span class="mw-page-title-main">Cyanate</span> Anion with formula OCN and charge –1

The cyanate ion is an anion with the chemical formula OCN. It is a resonance of three forms: [O−C≡N] (61%) ↔ [O=C=N] (30%) ↔ [O+≡C−N2−] (4%).

<span class="mw-page-title-main">Mercury(II) cyanide</span> Chemical compound

Mercury(II) cyanide, also known as mercuric cyanide, is a poisonous compound of mercury and cyanide. It is an odorless, toxic white powder. It is highly soluble in polar solvents such as water, alcohol, and ammonia; slightly soluble in ether; and insoluble in benzene and other hydrophobic solvents.

<span class="mw-page-title-main">Mercury(II) thiocyanate</span> Chemical compound

Mercury(II) thiocyanate (Hg(SCN)2) is an inorganic chemical compound, the coordination complex of Hg2+ and the thiocyanate anion. It is a white powder. It will produce a large, winding "snake" when ignited, an effect known as the Pharaoh's serpent.

<span class="mw-page-title-main">Potassium fulminate</span> Chemical compound

Potassium fulminate is the potassium salt of the fulminate ion. Its only use, aside from chemical demonstrations, is in the percussion caps for some early rifles. Usually prepared by reacting a potassium amalgam with mercury fulminate, it is much less sensitive due to the ionic bond between potassium and carbon, unlike the weaker covalent bond between mercury and carbon.

<span class="mw-page-title-main">Tetrazene explosive</span> Chemical compound

Tetrazene is an explosive material used for sensitization of priming compositions. It is a derivative of the compound with the IUPAC name tetrazene.

<span class="mw-page-title-main">Silver nitride</span> Chemical compound

Silver nitride is an explosive chemical compound with symbol Ag3N. It is a black, metallic-looking solid which is formed when silver oxide or silver nitrate is dissolved in concentrated solutions of ammonia, causing formation of the diammine silver complex which subsequently breaks down to Ag3N. The standard free energy of the compound is about +315 kJ/mol, making it an endothermic compound which decomposes explosively to metallic silver and nitrogen gas.

Sodium cyanate is the inorganic compound with the formula NaOCN. A white solid, it is the sodium salt of the cyanate anion.

<span class="mw-page-title-main">Nickel hydrazine nitrate</span> Chemical compound

Nickel hydrazine nitrate (NHN), (chemical formula: [Ni(N2H4)3](NO3)2 is an energetic material having explosive properties in between that of primary explosive and a secondary explosive. It is a salt of a coordination compound of nickel with a reaction equation of 3N2H4·H2O + Ni(NO3)2 →〔Ni(N2H4)3〕(NO3)2 + 3H2O

References

  1. 1 2 Wisniak, Jaime (2012). "Edward Charles Howard. Explosives, meteorites, and sugar". Educación Química. Universidad Nacional Autonoma de Mexico. 23 (2): 230–239. doi: 10.1016/s0187-893x(17)30114-3 . ISSN   0187-893X.
  2. Edward Howard (1800). "On a New Fulminating Mercury". Philosophical Transactions of the Royal Society of London . 90 (1): 204–238. doi:10.1098/rstl.1800.0012. S2CID   138658702.
  3. W. Beck; J. Evers; M. Göbel; G. Oehlinger; T. M. Klapötke (2007). "The Crystal and Molecular Structure of Mercury Fulminate (Knallquecksilber)". Zeitschrift für anorganische und allgemeine Chemie . 633 (9): 1417–1422. doi: 10.1002/zaac.200700176 .
  4. "The Sciences - Fulminating Substances". Scientific American. 11 June 1853.
  5. W. E. Garner & H. R. Hailes (1933). "Thermal decomposition and detonation of mercury fulminate". Proceedings of the Royal Society of London. 139 (1–3): 1–40. Bibcode:1933CP....334..128S. doi: 10.1098/rspa.1933.0040 .
  6. Hare2012-11-01T10:38:00+00:00, Jonathan. "Breaking Bad IV – can a little crystal blow up a room?". RSC Education. Archived from the original on 30 September 2023.{{cite web}}: CS1 maint: numeric names: authors list (link)