Nitrogen energy decomposition

Considering the low energy level of elemental nitrogen, the decomposition enthalpy ofp-ethoxyphenylpentazole (5.4 kcal/mole) indicates the high resonance energy of the pentazole system. 

A marked difference exists between the behavior pattern of silica and alumina, in the case of prolonged irradiation this particular feature is worth mentioning, even if it is not immediately relevant to the problem under examination. While the nitrogen fixation is progressing, the G pp of the reaction decreases in both%ases. This quite normal decrease is more apparent as equilibrium is approached, when the opposite nitrogen oxide decomposition is more important. Nevertheless, decrease of G is seen to be much more rapid for silica than for alumina, especially for energy amounts... 

Ammonium nitrate decomposes into nitrous oxide and water. In the solid phase, decomposition begins at about I50°C (302°F) but becomes extensive only above the melting point (I70°C) (338°F). The reaction is first-order, with activation energy about 40 kcal/g mol (72,000 Btii/lb mol). Traces of moisture and Cr lower the decomposition temperature thoroughly dried material has been kept at 300°C (572°F). All oxides of nitrogen, as well as oxygen and nitrogen, have been detected in decompositions of nitrates. 

Both symmetrical and unsymmetrical azo compounds can be made, so that a single radical or two different ones may be generated. The energy for the decomposition can be either thermal or photochemical. In the thermal decomposition, it has been established that the temperature at which decomposition occurs depends on the nature of the substituent groups. Azomethane does not decompose to methyl radicals and nitrogen until temperatures above 400°C are reached. Azo compounds that generate relatively stable radicals decompose at much lower temperatures. Azo compounds derived from allyl groups decompose somewhat above 100°C for example ... 

In view of the enthalpy and activation energy (see Section II, B, 1) of the decomposition of arylpentazoles the activation energy for the reversal of the decomposition, the 1,3-addition of elementary nitrogen to arylazides, can be estimated to be 25-30 kcal/mole, an amount which does not exclude the reaction. To ascertain whether the decomposition of arylpentazoles is a reversible reaction, p-ethoxyphenylazide-[j8-N ] (see Section II, B, 3) adsorbed on charcoal was exposed to unlabeled nitrogen (45-50°, 380 atm, 100 hr), but the anticipated exchange of between the reactants was not detected. ... 

The decomposition of methanesulphonyl azide in isopropyl alcohol could be effected by selective irradiation of 2-acetonaphthone instead of benzophenone 21>. Since 2-acetonaphthone triplets are incapable of hydrogen abstraction from isopropyl alcohol 22>, initiation must occur via transfer of excitation energy to the azide. A marked difference was observed from benzophenone sensitization in that the reaction was extremely slow, gave a nitrogen yield of only 68%, and produced a yellow solution 21>. 

The title compound (with 66.5% nitrogen content) is prepared by condensing formylhydrazine (2 mols, with elimination of 2H2O) by heating to 170°C. Dining a pilot production run in a 500 1 reactor, an explosion destroyed the vessel. The heat of decomposition of the compound was determined by thermal analysis as 1.5 kJ/g, with an energy of activation of 91 kJ/mol. 

Widmann, G. et al Thermochim. Acta, 1988, 134, 451-455 The energy of decomposition of Prussian blue in air in the range 210-360°C was determined by DSC as 2.42 kJ/g, peaking at 271 °C. When nitrogen was used as inerting gas in the sealed micro-crucible, decomposition was delayed to 250-350°C with a broad peak. 

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