Spontaneous Explosions

The iodine compound is more stable and separates as so-called nitrogen trHodide monoammoniate [14014-86-9], NI NH, an insoluble brownish-black soHd, which decomposes when exposed to light in the presence of ammonia. In reactions of the halogens with the respective ammonium salts, however, the action is different. Chlorine replaces hydrogen and nitrogen chloride [10025-85-1], NCl, separates as oily, yeUow droplets capable of spontaneous explosive decomposition. 

These batteries are used mainly for specialized technical equipment where power sources of small size but high power are needed. During early production years, cases of rather violent spontaneous explosion were observed, so that domestic uses were ruled out. The specihc energy can be as high as 1000 Wh/kg, which is the highest value among known types of electrochemical power sources. 

Alkyl nitrates become spontaneously explosive if they contain nitrogen oxides. 

When nitromethane comes into contact with silver nitrate, this can cause spontaneous explosions that are explained by the formation of explosive silver fulminate (see reaction below). 

Olah, G. A. et al., J. Inorg. Nucl. Chem., 1960, 14, 295-296 Experimental directions must be followed exactly to prevent violent spontaneous explosions during preparation of the salt from silver oxide and boron trifluoride etherate in nitromethane, according to the earlier method [1], The later method [3] is generally safer than that in [2],... 

Simons, H. P. el al., Ind. Eng. Chem., 1958, 50, 1665, 1659 Effects of presence of moisture or benzene vapour in air on the spontaneously explosive reaction have been studied. 

It is somewhat endothermic (AH°f (g) +87.5 kJ/mol, 1.0 kJ/g), the liquid may explode on pouring or sparking at 2°C, and the gas readily explodes on rapid heating or sparking [1,2], on adiabatic compression in a U-tube, or often towards the end of slow thermal decomposition. Kinetic data are summarised [3], The spontaneously explosive decomposition of the gas was studied at 42-86°C, and induction periods up to several hours were noted [4], Preparative precautions have been detailed [5],... 

The spontaneously explosive interaction of dichlorine oxide with methane, ethane, propane, ethylene or butadiene was investigated at 50-150°C. Self-heating occurs with ethylene, ethane and propane mixtures. 

The azide is very explosive, even when moist. Loosening the solid from filter paper caused frictional initiation. Explosion initiated by impact is very violent, and spontaneous explosion has also been recorded [1], It is also an exceptionally powerful initiator [2]. Detonation of the azide when dry has been confirmed [3], Good crystals are considerably more sensitive to shock, friction and electric discharge than is powder [4],... 

Interaction at — 20°C produces potassium trioxide, a spontaneously explosive solid [1], Later references suggest that these compounds are not spontaneously explosive [2,3]. 

The main factors leading to spontaneous explosions of blasting explosives in sulfide ore mines are identified as presence of ammonium nitrate, presence of pyrites and their weathering products, as well as the pH and temperature. At pH below 2, the critical temperature for spontaneous explosion may be lower than 40°... 

The very high friction-sensitivity, particularly of large crystals, and brisance on explosion are to be expected from the thermodynamic properties of the salt. Its great sensitivity, even under water, renders it unsuitable as a practical detonator [1], Spontaneous explosions dining interciystalline transformations have been observed, or on crystallisation from hot water [2], A safe method of preparing solutions in aqueous THF for synthetic purposes is available [3],... 

Spontaneous explosions have been observed [1] with this dangerously explosive material, especially when pure. A sample at 0°C exploded during removal of traces of benzene under high vacuum [2], A residue containing the tetraazide, silicon chloride triazide and probably silicon dichloride diazide, exploded on standing for 2 or 3 days, possibly owing to hydrazoic acid produced by hydrolysis. 

A boron analog - sodium borohydride - was prepared by reaction of sodium hydride with trimethyl borate [84 or with sodium fluoroborate and hydrogen [55], and gives, on treatment with boron trifluoride or aluminum chloride, borane (diborane) [86. Borane is a strong Lewis acid and forms complexes with many Lewis bases. Some of them, such as complexes with dimethyl sulfide, trimethyl amine and others, are sufficiently stable to have been made commercially available. Some others should be handled with precautions. A spontaneous explosion of a molar solution of borane in tetrahydrofuran stored at less than 15° out of direct sunlight has been reported [87]. 

Bromine pentafluoride is a highly reactive compound combining explosively or with ignition with most elements and their compounds. Spontaneous explosion or flaming can occur when mixed with water, organic compounds, metal powder, metal hahdes, metal oxides, metal sulfides and chlorine (upon warming) (Patnaik, P. 1999. A Comprehensive Guide to the Hazardous Properties of Chemical Substances, 2nd ed. New York John Wdey). 

H. Ellern D.E. Olander, "Spontaneous Explosion of a Normally Stable Complex Salt , JChemEduc 32, 24(1955) [The salt which spontaneously exploded was pure Trihydrazinenickel(II) nitrate prepd by adding an ethanolic soln of nickelous nitrate, slowly and with agitation, to a 40% ethanolic soln of hydrazine hydrate. The pptd fine pink pdr was separated, washed with ethanol and then dried for 16 hrs in... 

Ellern and Olander (Ref 4) report a spontaneous explosion of a thoroughly washed and dried nickel nitrohydrazinate [Ni(N2H4)3-(N03)2] after exposure to the atm for 10 min... 

NH4 Cl ratios, r, was found to be the lowest for r= 1 2. The mixts, when stored over CaCl2, undergo spontaneous explosion after 30-50 days, but stabilizers such as 2% of MgO, CaO, CaC2,... 

Temperature of storage It has been established by a number of investigators notably Will [24], Robertson [25], Farmer [26-28] and Hinshelwood [29] that all explosives undergo a thermal decomposition at temperatures far below those at which spontaneous explosion occurs. Therefore, decomposition reactions are of considerable importance in determining stability of explosives and it can be determined by measuring their rate of decomposition at elevated temperatures. 

As stated above, Wohler and Krupko [80] noticed that lead azide may explode during crystallization. Miles [75] confirmed this and stated that spontaneous explosion could occur during the growth period of crystals of /Head azide, i.e. when the two solutions forming the crystals diffused slowly. When isolated, however, the crystals (some of which had reached a length of 4 cm) were not found to be particularly sensitive. 

Spontaneous explosions of lead azide also take place during crystallization from saturated solution in ammonium acetate. A detailed study of this phenomenon has been made by Taylor and A. T. Thomas [105]. When the concentration of the solutions and the temperature and conditions of cooling were carefully controlled, they were able to predict the time at which spontaneous explosions occur. E.g. ... 

Taylor and Thomas have shown that spontaneous explosions are not associated with the large crystals of lead azide that are formed they filtered off-large crystals ca. 30 min before the predicted time of explosion and at the predicted time the mother liquor exploded while the filtered lead azide crystals remained intact. 

According to Kaufman [91] spontaneous explosion can also take place during the growth of a-lead azide crystals, e.g. when a supersaturated solution of lead azide in ammonium acetate is seeded with crystals of the a-form. Spontaneous explosions have also been observed with mercuric azide and in some cases with cadmium azide. 

According to Sudo [96] spontaneous explosion can occur during the formation of lead azide from sodium azide and lead acetate, when the concentration of reacting solutions is high (10% or more). 

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