Ammonium reactions

When organics containing reduced nitrogen are degraded, they usually produce ammonium, which is in equilibrium with ammonia. As the pK for NH3 NH4" is 9.3, the ammonium ion is the primary form present in virtually all biological treatment systems, as they operate at pH < 8.5 and usually in the pH range of 6.5-7.5. In aerobic reactions, ammonium is oxidized by nitrifying bacteria (nitrosomonas) to nitrite... 

Europium oxide (EU2O3) nanorods have been prepared by the sonication of an aqueous solution of europium nitrate in the presence of ammonia. In this reaction, ammonium ions adsorbed on the Eu(OH)3 particles (formed due to the collapse of the bubbles) results in the formation of a monolayer which then fuse together by hydrogen bonding leading to the formation of nanorods [28]. 

In the manufacture of PVC plastisol propellants, the usual care is taken to assure that all ingredients meet specifications for chemical composition, dryness, and particle size. Since PVC plastisol propellants do not involve chemical reaction in their curing process, however, the presence of certain impurities in the ingredients is far less critical than with those propellant systems that are solidified by polymerization reaction. Ammonium perchlorate, the most common oxidizer, can normally be procured from the supplier with the required low moisture content. If not, it is dried immediately before use. Tray dryers or other drying means may be used, depending upon the quantity of material. Normally, some or all of the oxidizer must be ground to achieve the desired mean particle size and particle-size distribuion. High speed hammer mills have proved... 

Thus, in the first stage of reaction, ammonium perchlorate and cyanamide are produced. The latter furnishes melamine, which is decomposed in turn under the influence of ammonium perchlorate or the perchloric acid that is produced from the perchlorate. 

Fig. 1. A new process (Urea Technologies) developed for the Tennessee Valley Authority operates at considerable energy savings. Urea is produced in an overall exothermic reaction of ammonia and carbon dioxide at elevated pressure and temperature. In a highly exothermic reaction, ammonium carbamate is first formed as an intermediate compound, followed by its dehydration to urea and water, which is a slightly endothermic reaction. The conversion of CO2 and NH3 to urea depends oil the ammonia-to-caibon dioxide ratio, temperature, and water-to-carbon dioxide ratio, among other factors. The new process makes maximum use of the heat created in the initial reaction, including heat recycling. 1 Urea Technologies and Tennessee Valley Authority)...

According to A. Hantzsch and L. Kaufmann,1 if dry ammonia be passed into the ethereal soln. of hyponitrous acid, ammonium hydrohyponitrite, (NH4)HN202, or NH4O.N N.OH, is formed in colourless crystals which melt with turbulent decomposition at 64°-65°. The salt spontaneously decomposes into ammonia, nitrous oxide, and water. The salt dissolves in water with an alkaline reaction. Ammonium hyponitrite, NH4O.N H.ONH4, cannot be prepared directly, but... 

During the opening of an epoxide, an alkoxide is liberated which may then be the cause of undesired side reactions. Ammonium chloride is often added to the reaction mixture to neutralise the alkoxide produced. 

With an excess of carbon monoxide Berthelot finds substances which seem related to parabanic acid. If water occurs in the reactions, ammonium nitrite is present. 

Summary Sulfur nitride is conveniently prepared by passing dry anhydrous ammonia gas into a benzene or toluene solution of sulfur chloride. During the reaction, ammonium chloride and sulfur precipitates, and towards the end of the reaction, red fumes will develop. When red fumes evolve, the reaction is complete. Thereafter, the reaction mixture is filtered, and then evaporated to yield dry crystals. These crystals are then recrystallized from toluene to yield high purity sulfur nitride. 

Figure 2. Calibration curve for ammonia analysis by Nesslers reaction (ammonium chloride).

Ammonia generated reacts with acetic acid forming ammonium acetate. To regenerate acetic acid from acetate, hydrochloric acid is added towards the end of the hydrolysis reaction. Ammonium chloride also forms, while acetic acid is regenerated. 

Ammonia (the base) accepts a proton from water (the acid) to form the ammonium ion (the conjugate acid of the base, ammonia) and hydroxide ion (the conjugate base of the acid, water). Another way of looking at the equation is that both sides have an acid and a base. In the forward reaction (—>) ammonia is the base, and water is the acid. In the reverse reaction (<—), ammonium ion, NH4+, is the acid, and hydroxide ion, OH , is the base. Each acid in the equation is related to a base on the opposite side... 

As we see in the reverse reaction, ammonium ion, NH4+, is the conjugate acid of NH3. The hydroxide ion, OH , is the conjugate base of water. In three dimensions, the molecular structures are... 

If the reaction mixture can be removed readily from the reaction vessel, it is best to pour it first on to ice and then, if necessary, after addition of more ice, to run in a suitable acid to the desired concentration. When acid may lead to polymerization or other undesirable reactions, ammonium chloride solution is used. 

In a reaction involving ammonia and water, ammonia (NH3) is a base because it accepts a proton, and water is an acid because it donates a proton. Thus, HO is the conjugate base of H2O, and ( NH4) is the conjugate acid of (NH3). In the reverse reaction, ammonium ion ( NH4) is an acid because it donates a proton, and hydroxide ion (HO ) is a base because it accepts a proton. 

For nitric acid-based liquid explosives, macromolecule monomers, which would be cross-linked to form network structure, are used in thickening methods [24]. The initiator should be capable of generating free radicals at low temperatures in the course of the reaction. Ammonium peroxydisulfate is able to be an initiator. The initial radial reaction is given as ... 

Ammonium is determined in many laboratories in a CF system in which the Berthelot reaction is implemented. In the Berthelot reaction, ammonium reacts with chlorine and phenol in the presence of sodium nitroprusside as catalyst in alkaline medium. EDTA is added to prevent interference of calcium and magnesium. Modern systems have been developed that use macroporous polytetrafluoroethylene (PTFE) membranes. In these systems a sample is introduced into a stream to which sodium hydroxide solution is added. Ammonia diffuses through the PTFE membrane into a stream of de-ionized water and the stream is fed through the flow-through cell of a conductivity meter. In this system a minimum of reagents is required and the only interference is from volatile amines. 

Temperature changes that accompany dissolution of ammonium nitrate in water are measured. Lee R. Summerlin and lames L. Ealy, )r., "Endothermic Reaction Ammonium Nitrate," Chemical Demonstrations, A Sourcebook for Teachers, Vol. 2 (Washington American Chemical Society, 1988) p. 65. 

Nova et al. [37] presented a global kinetic model for ammonia SCR over a Cu-zeolite catalyst. They used the same seven reactions as presented above (Eqs. 12.21-12.27). In addition, they added two more reactions. In the first reaction (Eq. 12.28), N2O is formed from a reaction between ammonia on the surface (denoted NH3) and NO and in the second reaction, ammonium nitrate is formed... 

P-2-P using the Leuckart reaction Ammonium formate Formic acid... 

The efficient one-pot three-component synthesis of pyrroles 51 in PEG 400 was developed (Sdieme 28) [52]. The reaction proceeded with various amines, however, anilines gave better yields (80-89%) of the product 51 than alkyl-amines (59-75%). Using in the same reaction ammonium acetate as the aminocomponent resulted in 41% yield of the... 

More recently, Kim et al. combined the copper-catalyzed C—H and C—B bond activation with the copper-catalyzed generation of cyanide anion in one pot to develop an efficient synthesis of aryl nitriles (Scheme 5.81) [83], which are important both in the pharmaceutical industry and in organic synthesis. In this cyanation reaction, ammonium iodide and DMF were used as the source of nitrogen and carbon atom of the cyano unit, respectively (Scheme 5.82). It is assumed that DMF is initially oxidized to its iminium species A upon the reduction of Cu(II) salts to Cu(I). Cyanide ion is envisioned to form on the reaction of A with anunonia, presumably via an amidinyl species B. The reaction is believed to proceed via a two-step process initial iodination and then cyanation. In the first step, the key intermediate iodoarene C is formed through the reaction of boronates with certain plausible iodide sources, such as NH I or the in situ-generated Cul and where copper species facilitate its conversion in the latter two cases. In the second step, cyanation of C takes place presumably upon the reaction with either cyanide anion under copper-mediated... 

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