The Chemistry of Powder and Explosives - Sciencemadness Dot Org

408 PRIMARY EXPLOSIVES, DETONATORS, AND PRIMERS
precipitate of the mercuric salt of nitromethane which gradually
becomes yellow and which, digested with warm dilute hydrochloric
acid, yields mercury fulminate. 7
^.o
CH2=N( N0Na
Sodium fulminate, soluble in water, has a molecular weight which
corresponds 8 to the simple monomolecular formula, NaONC.
These facts, taken together with the fact that mercury fulminate
warmed with concentrated aqueous hydrochloric acid yields hydroxylamine
and formic acid, 9 prove that fulminic acid is the
oxime of carbon monoxide.
HO—N=C + 2H2O > HO—NH2 + H—COOH
Mercury fulminate dissolves readily in an aqueous solution of
potassium cyanide to form a complex compound from which it
is reprecipitated by the addition of strong acid. It dissolves in
pyridine and precipitates again if the solution is poured into
water. A sodium thiosulfate solution dissolves mercury fulminate
with the formation of mercury tetrathionate and other inert
compounds, and this reagent is used both for the destruction of
fulminate and for its analysis. 10 The first reaction appears to be
as follows.
Hg(0NC)2 + 2Na4S2O! + H2O > HgS4O6 + 2NaOH + NaCN + NaNCO
The cyanide and cyanate are salts of weak acids and are largely
hydrolyzed, and the solution, if it is titrated immediately, appears
to have developed four molecules of sodium hydroxide for
every molecule of mercury in the sample which was taken. If the
solution is allowed to stand, the alkalinity gradually decreases
because of a secondary reaction whereby sulfate and thiocyanate
are formed.
7 Nef, Ann., 280, 275 (1894); Jones, Am. Chem. J., 20, 33 (1898).
8\V6hler, Ber., 43, 754 (1910).
9 Carstenjen and Ehrenberg, J. prak. Chem., [2] 25, 232 (1883); Steiner,
Ber., 16, 1484, 2419 (1883); Divers and Kawita, J. Chem. Soc, 45, 17 (1884).
10 Brownsdon, Chem. News, 89, 303 (1904); Philip, Z. ges. Schiess-
Sprengstoffw., 7, 109, 156, 180, 198, 221 (1912); Taylor and Rinkenbach,
"Explosives, Their Materials, Constitution, and Analysis," U, S. Bureau oj
Mines Bulletin 219, Washington, 1923, p. 62.