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FULMINIC ACID, HCNO

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Originally appearing in Volume V11, Page 300 of the 1911 Encyclopedia Britannica.
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FULMINIC See also:

ACID, HCNO or H2C2N202, an organic acid isomeric with cyanic and cyanuric acids; its salts, termed fulminates, are very explosive and are much employed as detonators. The See also:free acid, which is obtained by treating the salts with acids, is an oily liquid smelling like prussic acid; it is very explosive, and the vapour is poisonous to about the same degree as that of prussic acid. The first fulminate prepared was the " fulminating See also:silver "of L. G. Brugnatelli, who found in 1798 that if silver be dissolved in nitric acid and the See also:solution added to See also:spirits of See also:wine, a See also:white, highly explosive See also:powder was obtained. This substance is to be distinguished from the See also:black " fulminating 1 A name misapplied in the See also:southern hemisphere to Diomedea melanophrys, one of the albatrosses.silver " obtained by C. L. Berthollet in 1788 by acting with See also:ammonia on precipitated silver See also:oxide. The next See also:salt to be obtained was the mercuric salt, which was prepared in 1799 by See also:Edward See also:Charles See also:Howard, who substituted See also:mercury for silver in Brugnatelli's See also:process. A similar method is that of J. von See also:Liebig (1823), who heated a mixture of See also:alcohol, nitric acid and mercuric nitrate; the salt is largely manufactured by processes closely resembling the last. A laboratory method is to mix solutions of See also:sodium nitromethane, See also:CH2: NO(ONa), and mercuric chloride, a yellow basic salt being formed at the same See also:time. Mercuric fulminate is less explosive than the silver salt, and forms white needles (with 4H20) which are tolerably soluble in See also:water.

The use of mercuric fulminate as a detonator See also:

dates from about 1814, when the explosive cap was invented. It is still the commonest detonator, but it is now usually mixed with other substances; the See also:British service uses for percussion caps 6 parts of fulminate, 6 of See also:potassium chlorate and 4 of See also:antimony sulphide, and for time fuses 4 parts of fulminate, 6 of potassium chlorate and 4 of antimony sulphide, the mixture being damped with a shellac See also:varnish; for use in See also:blasting, a See also:home See also:office See also:order of 1897 prescribes a mixture of 4 parts of fulminate and 1 of potassium chlorate. In 1900 Bielefeldt found that a fulminate placed on See also:top of an aromatic nitro See also:compound, such as trinitrotoluene, formed a useful detonator; this See also:discovery has been especially taken See also:advantage of in See also:Germany, in which See also:country detonators of this nature are being largely employed. Tetranitromethylaniline (tetryl) has also been employed (Brit. Pat. 13340 of 1905). It has been proposed to replace fulminate by silver See also:azoimide (See also:Wohler & See also:Matter, Brit. Pat. 4468 of 19(38), and by See also:lead azoimide (Hyronimus, Brit. Pat. 1819 of 1968). The constitution of fulminic acid has been investigated by many experimenters, but apparently without definitive results.

The researches of Liebig (1823), Liebig and See also:

Gay-Lussac (1824), and of Liebig again in 1838 showed the acid to be isomeric with cyanic acid, and probably (HCNO)2, since it gave mixed and acid salts. See also:Kekule, in 1858, concluded that it was nitroacetonitrile, NO2•CH,.CN, a view opposed by See also:Steiner (1883), E. See also:Divers and M. Kawakita (1884), R. See also:Scholl (189o), and by J. U. Nef (1894), who proposed the formulae: C : N•OH N : CH CH : N•O , : N•OH, 0< N : C•OH, CH : NO, C : N .OH. Steiner, Divers, Scholl, Nef. The formulae of Kekule, Divers and See also:Armstrong have been discarded, and it remains to be shown whether Nef's carbonyloxime See also:formula (or the bimolecular formula of Steiner) or Scholl's glyoxime peroxide formula is correct. There is some doubt as to the molecular formula of fulminic acid. The existence of See also:double salts, and the observations of L. Wohler and K.

Theodorovits (See also:

Bey., 1905, 38, p. 345), that only compounds containing two See also:carbon atoms yielded fulminates, points to (HCNO)2; on the other See also:hand, Wohler (loc. cit. p. 1351) found that cryoscopic and electric conductivity measurements showed sodium fulminate to be NaCNO. Nef based his formula, which involves bivalent carbon, on many reactions; in particular, that silver fulminate with hydrochloric acid gave salts of formylchloridoxime. which with water gave See also:hydroxylamine and formic acid, thus C: NO OAg_HC<NOAg_HCCOH H---> H.0O2H+H2N•0H, and also on the See also:production from sodium nitromethane and mercuric chloride, thus CH2 :NO.Ohg-See also:H2O-I--C :NOhg(hg=1Hg). H. See also:Wieland and F. C. Palazzo (1907) support this formula, finding that methyl nitrolic acid, NO2.CH : N•OH, yielded under certain conditions fulminic acid, and See also:vice versa (Palazzo, 1907). M. Z. Jowitschitsch (See also:Ann., 1906, 347, p. 233) inclines to Scholl's formula; he found that the synthetic silver salt of glyoxime peroxide resembled silver fulminate in yielding hydroxylamine with hydrochloric acid, but differed in being less explosive, and in being soluble in nitric acid.

H. Wieland and his collaborators regard " glyoxime peroxide " as an oxide of furazane (q.v.), and have shown that a See also:

close relationship exists between the nitrile oxides, furoxane. and fulminic acid (see Ann. See also:Rep., See also:London Chem. See also:Soc., 1909, p. 84). Fulminuric acid, (HCNO)3, obtained by Liebig by boiling mercuric fulminate with water, was synthesized in 19o5 by C. Ulpiani and L. Bernardini (Gazetta, iii. 35, p. 7), who regard it as NO2•CH(CN)•CO•NH2. It deflagrates at 145°, and forms a characteristic cuprammonium salt. The See also:early See also:history of mercuric fulminate and a See also:critical See also:account of its application as a detonator is given in The Rise and Progress of the British See also:Explosives See also:Industry (See also:International See also:Congress of Applied See also:Chemistry, 1909).

The manufacture and See also:

modern aspects are treated in Oscar Guttmann, The Manufacture of Explosives, and Manufacture of Explosives, Twenty Years' Progress (1909).

End of Article: FULMINIC ACID, HCNO

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