Ammonium nitrite, decomposition

Nitrite can also react with ammonia to form ammonium nitrite which is stable in alkaline media but unstable under acid conditions. It decomposes to liberate nitrogen gas. This reaction, which is similar to or identical with the Van Slyke reaction discussed above, has been emphasized by many workers over the years. There is still little quantitative data that characterize the reaction with respect to concentration, temperature, pH, and effects of catalysts (Wilson, 1943 AlUson, 1966). Most recent workers, with the notable exception of Gerretsen and De Hoop (1957), seem to agree that there is no good evidence that loss of gaseous nitrogen via ammonium nitrite decomposition is likely to be... 

Heating a mixture of an ammonium salt with a nitrite salt causes a violent explosion on melting [1], owing to formation and decomposition of ammonium nitrite. Salts of other nitrogenous bases behave similarly. Mixtures of ammonium chloride and sodium nitrite are used as commercial explosives [2], Accidental contact of traces of ammonium nitrate with sodium nitrite residues caused wooden decking on a truck to ignite [3],... 

Nitrogen can also be obtained by the careful decomposition of ammonium nitrite,... 

Ray, P. C. et al., J. Chem. Soc., 1911, 99, 1470 1912, 101, 141, 216 Ammonium and substituted-ammonium nitrite salts exhibit a range of instability, and reaction mixtures which may be expected to yield these products should be handled with care. Ammonium nitrite will decompose explosively either as the solid, or in cone, aqueous solution when heated to 60-70°C. Presence of traces of acid lowers the decomposition temperature markedly. Hydroxylammo-nium nitrite appears to be so unstable that it decomposes immediately in solution. Hydrazinium(l+) nitrite is a solid which explodes violently on percussion, or less vigorously if heated rapidly, and hydrogen azide may be a product of decomposition [1], Mono- and di-alkylammonium nitrites decompose at temperatures below 60-70°C, but usually without violence [2], Individual entries are ... 

The mechanism of fast SCR over a zeolite-based catalyst has also been addressed by Sachtler and co-workers using an IR technique [69, 70]. They concluded that nitrogen is produced through fast decomposition of ammonium nitrite (the hydrated form of nitrosamide), vhich is formed from equimolar NO/NO2 feeds via N2O3 and its reaction vith water and ammonia ... 

A mixture of sodium nitrite with ammonium chloride may decompose with time to form unstable ammonium nitrite. The presence of moisture and of acids favours the decomposition of a mixture of sodium nitrite with ammonium chloride. On the other hand, alkaline reaction and absence of moisture stabilize the system. Experiments have shown that for all practical purposes the mixture is best stabilized by the addition of 2% sodium carbonate. Ammonium carbonate or magnesium oxide may also be used. 

Ammonium nitrite is explosive and very sensitive to heating. Explosive decomposition can occur even when an aqueous solution is heated to 60-70°C. Acidification of an aqueous solution with a drop of concentrated hydrochloric, sulphuric or nitric acid produces a spontaneous decomposition even at room temperature. 

Pure nitrogen can be prepared by the decomposition in aqueous solution of ammonium nitrite. 

Preparation of nitrogen. The preparation of pure nitrogen on a laboratory scale is best accomplished by the formation and subsequent decomposition of ammonium nitrite. These reactions are effected in aqueous solution by warming the reactants cautiously. 

Ammonium Cobalti-nitrite, 4(NH4)3Co(N02)s.3Ha0, was first prepared in 1856 by Gibbs and Genth. Erdmann 2 obtained it by the action of ammonium nitrite upon cobalt chloride solution acidulated with acetic acid. It may also be obtained by adding semicarbazide to a solution of sodium cobalti-nitrite 3 and by double decomposition of solutions of ammonium chloride and sodium cobalti-nitrite or by addition of nitrous acid to a suspension of cobalt carbonate in the requisite quantity of ammonium nitrite solution.4 In all three cases the salt is precipitated out. 

The average value of the rate constant is 0.0003879 s 1 Example From the following data for the decomposition of ammonium nitrite in aqueous solution, show that the reaction is first-order. 

The preparation of ammonium nitrite has been effected by various methods. Examples are the double decomposition of lead9 or barium8 nitrite and ammonium sulphate the action of nitrogen peroxide on ammonium hydroxide, and purification of the nitrite by fractional crystallization 10 passing a mixture of air and ammonia over heated platinized asbestos 11 and heating a very concentrated solution of ammonium chloride and sodium nitrite in vacuum between 60° and 80° C., the ammonium nitrite subliming into the neck of the flask.12 It... 

With the exception of silver nitrite, which is only slightly soluble, nitrite salts readily dissolve in water. The alkali metal nitrites and ammonium nitrite are hygroscopic. While sodium nitrite melts without decomposition, most other nitrites decompose before reaching the melting point (Ba(N02)2 > 593 K, AgN02 > 413 K, Hg(N02)2 > 348 K). Ammonium nitrite decomposes above 333 K, sometimes explosively, to dinitrogen and water ... 

Discrepancies in the experimental values of the molar mass of nitrogen provided some of the first evidence for the existence of the noble gases. If pure nitrogen is collected from the decomposition of ammonium nitrite,... 

A convenient method is by the decomposition of ammonium nitrite by heat ... 

Few reactions can have been studied over so long a period, with so little evidence of complex chemistry and yet so little agreement, as the decomposition of ammonium nitrite. Investigations are quantitative and apparently deal with the homogeneous reaction. There has also been interest in decomposition of the solid in presence of water vapour , and in the catalysis by platinum black of the reaction in solution . 

Molecular nitrogen is obtained by fractional distillation of air (the boiling points of liquid nitrogen and liquid oxygen are -196°C and -183°C, respectively). In the laboratory, very pure nitrogen gas can be prepared by the thermal decomposition of ammonium nitrite ... 

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