Nitrous oxide evolution

Method A The activated carbon was dried at 100°C / 0.1 mbar and stored under Argon. 1.7 - 1.8 g were impregnated with 7 ml of a saturated aqueous metal nitrate solution. The mixture was magnetically stirred for 20 min. The mushy dispersion was filtered by applying vacuum and using a commercially available filter paper. The residual solid was mechanically squeezed and dried for 30 min at 80 °C in an oven. Some metal nitrates like iron and chromium show nitrous oxide evolution. 

In the full scale fire tests some additional gaseous species were studied specifically, i.e. formaldehyde. Not all gas species were studied in every test. Hydrogen cyanide and hydrogen chloride have only been studied in situations where evolution of these species were suspected. HCN and HC1 have only been studied as collective (2, 5 or 10 minutes) samples for each fire test. It is most preferable to follow the concentrations with direct reading instruments. This has been the case for carbon monoxide, carbon dioxide, oxygen and in three out of four cases for nitrous oxide. Drager tubes were used for measurements of nitrous oxides in the DIN 53436 test. 

LAUGHING GAS (And/Or Press, 1973) is the best reference on the psychedelic effects of nitrous oxide. N20 can be produced by heating ammonium nitrate at 240° until gas evolution ceases (the... 

Hydroxylamine, although not commercially used as a developing agent, shows good selectivity under proper conditions. Its use in the study of reaction mechanism offers the distinct advantage that the rate of the reaction can be followed by measuring the rate of evolution of nitrogen or nitrous oxide. 

Heating ammonium nitrate can present a severe explosion hazard. When heated above 210°C, its decomposition is exothermic, producing nitrous oxide and water vapor. In closed confinement, heating the molten mass can cause a pressure build-up. Above 300°C, there is rapid evolution of nitrogen, water... 

In a 1.5-1. beaker (Note 1), 191 ml. (180 g.) of aqueous 25% dimethylamine solution (1.0 mole) is diluted with 64 ml. of water and treated with 116 g. (1.1 moles) of nitrourea.2 The temperature of the resulting brownish liquid rises spontaneously to 35-42°. The solution is warmed to 56-60°, and a reaction sets in vigorously with evolution of nitrous oxide. External cooling with water is applied when required the reaction temperature is maintained below 70° during the first 5-7 minutes and below 85° during the second period of 5-7 minutes. After a total of 10-15 minutes, the effervescence slackens and the reaction mixture is kept at 90-100° until the evolution of gas has completely ceased. This usually requires an additional 15-20 minutes. 

Methylenedinitramine undergoes decomposition under the influence of strong acids and strong bases. At a pH of about 1.0 and 10.0, however, it is fairly stable although it decomposes readily when the pH ranges between 3 and 8, the maximum of the decomposition rate occurring at pH 5.4 (Lamberton et al. [14]). Decomposition is accompanied by the evolution of nitrous oxide and formaldehyde. 

Its chemical stability is fairly high and only an insignificant amount decomposes on prolonged boiling in water. Boiling in dilute sulphuric acid causes decomposition with the evolution of nitrous oxide, acetaldehyde and ethylene glycol. 

Nitrourea, like nitroguanidine, is prepared by the action of sulphuric acid on urea nitrate. It was recommended as an explosive by Badische Anilin und Soda-Fabrik in 1915 [62] but without success, as it was not sufficiently stable. In the presence of water it decomposes at a little above 60°C with the evolution of nitrous oxide. 

The latter is unstable and undergoes decomposition in hot water with the evolution of formaldehyde, nitrous oxide and ammonium nitrate... 

Decomposition accompanied by the development of nitrous oxide compatible with the scheme (4) only starts above 170° C. Marked decomposition together with the evolution of nitrogen, nitric oxide and water, corresponding with the reaction (3), begins at a temperature of about 220°C [11]. 

Biogenic silicon (BSI) was determined, with minor modifications, by the method of DeMaster (17). As adapted, the technique involved time-course leaching of <20-mg samples of particulate matter in 30 mL of 1.0% Na2C03 in a water bath at 85 °C. Silica in leachates was quantified either colorimetrically (Technicon autoanalyzer procedure) or by nitrous oxide flame atomic absorption. A high-temperature catalytic-combustion technique (Perkin Elmer 240C) was used for particulate organic carbon determinations. Particulate inorganic (carbonate) carbon was measured on the same instrument by CO 2 evolution after treatment of the particles with phosphoric acid. 

The conversion of a carbohydrate C-nitroalcohol to the corresponding sugar is achieved simply by adding an aqueous solution of the sodium oci-nitroalcohol to a moderately concentrated aqueous sulfuric acid solution at room temperature. A copious evolution of nitrous oxide occurs during the addition and the resulting sugar then can be obtained from the reaction solution in yields of from 60 to 80 percent, depending upon the ease of isolation of the particular aldose produced. 

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