Nitrogen dissolution

Oxides of nitrogen Dissolution of targets in nitric acid will result... 

Beryllium Nitrate. BeryUium nitrate tetrahydrate [13516-48-0], Be(N02)2 4H2O, is prepared by crystallization from a solution of beryUium hydroxide or beryllium oxide carbonate in a slight excess of dilute nitric acid. After dissolution is complete, the solution is poured into plastic bags and cooled to room temperature. The crystallization is started by seeding. Crystallization from more concentrated acids yields crystals with less water of hydration. On heating above 100°C, beryllium nitrate decomposes with simultaneous loss of water and oxides of nitrogen. Decomposition is complete above 250°C. 

Agronomic Properties and Nutrient Release Mechanism. The conversion of UF reaction products to plant available nitrogen is a multistep process, involving dissolution and decomposition. Materials are slow to enter the soil solution by virtue of their low solubiUty. Longer polymer chain products are less soluble than shorter chains and take longer to become available to the plants. 

Cu(N03 )26H2 0, is produced by crystallization from solutions below the transition poiat of 26.4°C. A basic copper nitrate [12158-75-7] Cu2(N02)(0H)2, rather than the anhydrous product is produced on dehydration of the hydrated salts. The most common commercial forms for copper nitrate ate the ttihydtate and solutions containing about 14% copper. Copper nitrate can be prepared by dissolution of the carbonate, hydroxide, or oxides ia nitric acid. Nitric acid vigorously attacks copper metal to give the nitrate and evolution of nitrogen oxides. 

The reverse reaction to ammonia synthesis, the decomposition to nitrogen and hydrogen, is used in die nitriding of iron and canied out industiially at temperatures around 800 K and atmospheric pressure to produce surfacehardening. This dissolution reaction must also play a part in the synthesis of ammonia by the industiial process. The attempt to ninide non by reaction with nin ogen gas is vety slow under atmospheric pressure, presumably due to the stability of the nitrogen molecule. 

Because phenols are weak acids, they can be freed from neutral impurities by dissolution in aqueous N sodium hydroxide and extraction with a solvent such as diethyl ether, or by steam distillation to remove the non-acidic material. The phenol is recovered by acidification of the aqueous phase with 2N sulfuric acid, and either extracted with ether or steam distilled. In the second case the phenol is extracted from the steam distillate after saturating it with sodium chloride (salting out). A solvent is necessary when large quantities of liquid phenols are purified. The phenol is fractionated by distillation under reduced pressure, preferably in an atmosphere of nitrogen to minimise oxidation. Solid phenols can be crystallised from toluene, petroleum ether or a mixture of these solvents, and can be sublimed under vacuum. Purification can also be effected by fractional crystallisation or zone refining. For further purification of phenols via their acetyl or benzoyl derivatives (vide supra). 

Thiothienoyltrifluoroacetone [4552-64-1] M 228.2, m 61-62". Easily oxidised and has to be purified before use. This may be by recrystd from benzene or by dissolution in pet ether, extraction into IM NaOH soln, acidification of the aqueous phase with 1-6M HCl soln, back extraction into pet ether and final evapn of the solvent. The purity can be checked by TLC. It was stored in ampoules under nitrogen at 0" in the dark. [Muller and Rother Anal Chim Acta 66 49 1973.]... 

An alternative process from U.S. Patent 3,635,946 A vigorously stirred reaction mixture consisting of 32.B7 g (0.1 mol) of 5-fluorouracilmercury, 100 ml of dimethylformamide and 50 ml of toluene is dried by azeotropic distillation of toluene. It is then cooled to -40°C in a stream of dry nitrogen, and a solution of 21.3 g (0.2 mol) of 2-chlorofuranidin in 20 ml of dried dimethylformamide is gradually added to the stirred mixture, the temperature being maintained between -40°C and -30°C. After completion of the reaction (which is marked by complete dissolution of the starting 5-fluorouracilmercury) i.e. after about 3 to 4 hours, 60 to 80 ml of the solvent are distilled off in vacuo at a bath temperature not exceeding 35°C ... 

Streicher, M. A., The R61e of Carbon, Nitrogen and Heal Treatment in the Dissolution of Fe-Cr Alloys in Acids , Corrosion, 29, 337 (1973)... 

Determination of the nature of the sulfate content was attempted by following the conch of this impurity in two ways (1) during the course of laboratory simulated industrial stabilization procedures, and (2) from successive dissolutions of unstabilized NC samples in various solvents and subsequent repptn from non-solvents. This approach was based on the premise that free occluded sulfuric acid would be released from the fibers by the soln-pptn treatment, whereas chemically combined sulfate would remain unaffected. The fuli details of the various expts can be found in Ref 5 some typical results are shown in Table 3 for four samples of NC of different nitrogen content... 

The pentafluorophenylcopper tetramer is usually analytically pure as isolated and melts at 200° with decomposition. If any significant decomposition occurs during the final drying, the product can be purified by dissolution in ether, filtration to remove copper metal, and precipitation by addition of hexane. It can also be recrystallized from benzene. When kept in a sealed container under nitrogen at room temperature, pentafluorophenyl copper tetramer appears to be stable for reasonable periods. It can be stored indefinitely at -78° under an atmosphere of carbon dioxide. 

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