Ammonium nitrite

Ammonium nitrite [13446-48-5] NH4NO2, a compound of questionable stabiUty, can be prepared by reaction of barium nitrite and aqueous ammonium sulfate. After removal of the precipitated barium sulfate by filtration, the ammonium nitrite can be recovered from solution. The salt is said to decompose, sometimes explosively, at 60—70°C. 

Allied-Signal Process. Cyclohexanone [108-94-1] is produced in 98% yield at 95% conversion by liquid-phase catal57tic hydrogenation of phenol. Hydroxylamine sulfate is produced in aqueous solution by the conventional Raschig process, wherein NO from the catalytic air oxidation of ammonia is absorbed in ammonium carbonate solution as ammonium nitrite (eq. 1). The latter is reduced with sulfur dioxide to hydroxylamine disulfonate (eq. 2), which is hydrolyzed to acidic hydroxylamine sulfate solution (eq. 3). 

Hot aqueous solutions of ammonium nitrite also decompose to give nitrogen though small amounts of NO and HNO3 are also formed (p. 434) and must be removed by suitable absorbents such as dichromate in aqueous sulfuric acid ... 

Ammonium bromate (NH4Br03), ammonium nitrite (NH4N02), ammonium perborate (NH4B03), ammonium persulfate... 

Subsequently, the formed HN02 undergoes the same reactions via ammonium nitrite to nitrogen as shown in the upper part of Figure 9.12. More details about the SCR chemistry can, for example, be found in [32,33,37-41]. 

An explosion in the vent of an ammonia combustion plant was attributed to deposition of ammonium nitrite/nitrate crystals. It is considered that the very unstable nitrite acts as a sensitiser to the nitrate, and that explosion is triggered by contact with acid. 

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],... 

Interaction of nitrites when heated with metal amidosulfates (sulfamates) may become explosively violent owing to liberation of nitrogen and steam. Mixtures with ammonium sulfamate form ammonium nitrite which decomposes violently around 80°C. 

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 ... 

Ammonium nitrite is unstable above 100 °C and the sum of reactions (13.25) and (13.26) results in the fast SCR reaction (13.24). This reaction scheme can explain the optimal 1 1 NO NO2 feed ratio of the fast SCR on the basis of well-known chemistry however, it cannot explain all of the several products (N2, NH4NO3, N2O) observed in experiments covering the full range of NO NO feed ratios [71]. 

In the presence of NH3, nitrous acid forms ammonium nitrite, which readily decomposes to N2 ... 

The capability of NO to reduce nitrates, providing a pathway for the production of ammonium nitrite and thus of nitrogen, has also been demonstrated recently by Weitz and co-workers, mainly on the basis of IR data collected over BaNa-Y zeolite [75] however, according to a parallel additional route NO would also react with NO2 to form N2O3 and then nitrogen [reactions (13.25) and (13.26)], as already discussed. The oxidation of NO by surface nitrates over a Pt-Ba/Al2O3 catalyst has also been reported by Olsson et al. [76], whereas the formation of surface nitrates from NO2 on bare AI2O3 has been reported by Apostolescu et al. [77] and previously observed in our laboratories also [78]. 

Spongy copper slowly reduces it to ammonium nitrite in the absence of air however, no reaction occurs with copper wire or gauge. (Basset, H. and R. G. Durrant. 1922. J. Chem. Soc., 121, 2631) ... 

Ammonium nitrite is decomposed according to the following reaction. 

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