Sodium ammonium compound

Recovery of Ammonia. The filter Hquor contains unreacted sodium chloride and substantially all the ammonia with which the brine was originally saturated. The ammonia may be fixed or free. Fixed ammonia (ammonium chloride [12125-02-97]) corresponds stoichiometrically to the precipitated sodium bicarbonate. Free ammonia includes salts such as ammonium hydroxide, bicarbonate, and carbonate, and the several possible carbon—ammonia compounds that decompose at moderate temperatures. A sulfide solution may be added to the filter Hquor for corrosion protection. The sulfide is distilled for eventual absorption by the brine in the absorber. As the filter Hquor enters the distiller, it is preheated by indirect contact with departing gases. The warmed Hquor enters the main coke, tile, or bubble cap-fiUed sections of the distiller where heat decomposes the free ammonium compounds and steam strips the ammonia and carbon dioxide from the solution. 

The first reported synthesis of acrylonitrile [107-13-1] (qv) and polyacrylonitrile [25014-41-9] (PAN) was in 1894. The polymer received Htde attention for a number of years, until shortly before World War II, because there were no known solvents and the polymer decomposes before reaching its melting point. The first breakthrough in developing solvents for PAN occurred at I. G. Farbenindustrie where fibers made from the polymer were dissolved in aqueous solutions of quaternary ammonium compounds, such as ben2ylpyridinium chloride, or of metal salts, such as lithium bromide, sodium thiocyanate, and aluminum perchlorate. Early interest in acrylonitrile polymers (qv), however, was based primarily on its use in synthetic mbber (see Elastomers, synthetic). 

Arsenic Peroxides. Arsenic peroxides have not been isolated however, elemental arsenic, and a great variety of arsenic compounds, have been found to be effective catalysts ia the epoxidation of olefins by aqueous hydrogen peroxide. Transient peroxoarsenic compounds are beheved to be iavolved ia these systems. Compounds that act as effective epoxidation catalysts iaclude arsenic trioxide, arsenic pentoxide, arsenious acid, arsenic acid, arsenic trichloride, arsenic oxychloride, triphenyl arsiae, phenylarsonic acid, and the arsenates of sodium, ammonium, and bismuth (56). To avoid having to dispose of the toxic residues of these reactions, the arsenic can be immobi1i2ed on a polystyrene resia (57). 

A number of simple, standard methods have been developed for the analysis of ammonium compounds, several of which have been adapted to automated or instmmental methods. Ammonium content is most easily deterrnined by adding excess sodium hydroxide to a solution of the salt. Liberated ammonia is then distilled into standard sulfuric acid and the excess acid titrated. Other methods include colorimetry (2) and the use of a specific ion electrode (3). 

Ammonium nitrate [6484-S2-2J, NH NO, formula wt 80.04, is the most commercially important ammonium compound both Hi terms of production volume and usage. It is the principal component of most iadustrial explosives and nonmilitary blasting compositions however, it is used primarily as a nitrogen fertilizer. Ammonium nitrate does not occur Hi nature because it is very soluble. It was first described Hi 1659 by the German scientist Glauber, who prepared it by reaction of ammonium carbonate and nitric acid. He called it nitrium flammans because its yeUow flame (from traces of sodium) was... 

Sodium nitrate is used as a fertiliser and in a number of industrial processes. In the period from 1880—1910 it accounted for 60% of the world fertiliser nitrogen production. In the 1990s sodium nitrate accounts for 0.1% of the world fertiliser nitrogen production, and is used for some specific crops and soil conditions. This decline has resulted from an enormous growth in fertiliser manufacture and an increased use of less expensive nitrogen fertilisers (qv) produced from synthetic ammonia (qv), such as urea (qv), ammonium nitrate, ammonium phosphates, ammonium sulfate, and ammonia itself (see Ammonium compounds). The commercial production of synthetic ammonia began in 1921, soon after the end of World War I. The main industrial market for sodium nitrate was at first the manufacture of nitric acid (qv) and explosives (see Explosives and propellants). As of the mid-1990s sodium nitrate was used in the production of some explosives and in a number of industrial areas. 

Acids such as sulfuric or nitric acids or bases such as sodium hydroxide may catalyze the hydrolysis of PET. It has been demonstrated that the rate of alkaline PET hydrolysis increases in the presence of quaternary ammonium compounds.26 27 Niu et al.26 reported an increase in the rate of alkaline PET degradation in the presence of dodecylbenzyldimethylammonium chloride at 80°C. Polk et al.27 reported increases in the rate of sodium hydroxide depolymerization of PET in the presence of trioctylmethylammonium chloride, trioctyl-methylammonium bromide, and hexadecyltrimethylammonium bromide at 80° C. 

Polk et al. reported27 that PET fibers could be hydrolyzed with 5% aqueous sodium hydroxide at 80°C in the presence of trioctylmethylammonium bromide in 60 min to obtain terephthalic acid in 93% yield. The results of catalytic depolymerization of PET without agitation are listed in Table 10.1. The results of catalytic depolymerization of PET with agitation are listed in Table 10.2. As expected, agitation shortened the time required for 100% conversion. Results (Table 10.1) for the quaternary salts with a halide counterion were promising. Phenyltrimethylammonium chloride (PTMAC) was chosen to ascertain whether steric effects would hinder catalytic activity. Bulky alkyl groups of the quaternary ammonium compounds were expected to hinder close approach of the catalyst to the somewhat hidden carbonyl groups of the fiber structure. The results indicate that steric hindrance is not a problem for PET hydrolysis under this set of conditions since the depolymerization results were substantially lower for PTMAC than for die more sterically hindered quaternary salts. 

In the case of quaternary ammonium compounds the chromatograms can be treated afterwards with sodium nitrite solution in order to intensify the color [27]. 

Cationic salts Tetraalkyl quaternary ammonium compounds Triethylamine, sodium nitrate... 

The use of ion pairing agents, such as sodium benzenesulfonate, may be helpful in the analysis of complex mixtures of quaternary ammonium compounds, as they modify their retention times418. 

Crystals composed of the R and S enantiomers of the same racemic mixture must be related by mirror symmetry in terms of both their internal structure and external shape. Enantiomorphous crystals may be sorted visually only if the crystals develop recognizable hemihedral faces. [Opposite (hid) and (hkl) crystal faces are hemihedral if their surface structures are not related to each other by symmetry other than translation, in which case the crystal structure is polar along a vector joining the two faces. Under such circumstances the hemihedral (hkl) and (hkl) faces may not be morphologically equivalent.] It is well known that Pasteur s discovery of enantiomorphism through die asymmetric shape of die crystals of racemic sodium ammonium tartrate was due in part to a confluence of favorable circumstances. In the cold climate of Paris, Pasteur obtained crystals in the form of conglomerates. These crystals were large and exhibited easily seen hemihedral faces. In contrast, at temperatures above 27°C sodium ammonium tartrate forms a racemic compound. 

K bicarbonate, K chloride, K iodide, K metaphosphate, K perchlorate, K phosphate, K silico-fluoride, K urea oxalate, sodium ammonium sulfate, sulfur, zinc sulfate and Zr oxide It was claimed that methylene urea reduced the flash to a far greater extent than any of the organic compounds used, ft was also stated that cerium salts were much more effective than any other metallic salts investigated (Ref 4)... 

Through luck, in 1848, Louis Pasteur was able to separate or resolve racemic tartaric acid into its (+) and (—) forms by crystallization. Two enantiomers of the sodium ammonium salt of tartaric acid give rise to two distinctly different types of chiral crystal that can then be separated easily. However, only a very few organic compounds crystallize into separate crystals (of two enantiomeric forms) that are visibly chiral as are the crystals of the sodium ammonium salt of tartaric acid. Therefore, Pasteur s method of separation of enantiomers is not generally applicable to the separation of enantiomers. 

E. Filhol and J. B. Senderens claim to have made Sodium ammonium sesquiphos-phate, Na3P04.(NH4)3P04.2H3P04.3H20, analogous to the sodium salt (q.v.). This compound—if it be a compound—is said to be very unstable and readily decomposed by water into an acid and a basic salt. 

Figure 11.13 Adsorption isotherms for a series of alkyl ammonium compounds on sodium montmoril-lonite (adapted from Cowan and White. 1958). The horizontal dashed line indicates the cation exchange capacity of the clay.

Ammonium Compounds and Organic Bodies Such as Occur in Unpurified Glycerin. — On heating 1 cc. of glycerin with 1 cc. of sodium hydroxide solution, no ammonia should be evolved (to be detected by means of moistened litmus paper) nor should a color develop nor an odor resembling that of glue. 

Ammonium Compounds. — On heating the solution of 1 gm. of potassium and sodium tartrate in 10 cc. of water with 10 cc. of sodium hydroxide solution (sp. gr. 1.3), no vapors of ammonia should be given off (to be ascertained by means of moist litmus paper). 

Ammonium Compounds. — On adding 1 cc. of Nessler s reagent to a solution of 10 gm. of sodium carbonate in 50 cc. of water, no change should be observed. 

Salts therefore, are prepared (1) from solutions of acids and bases by neutralization and separation by evaporation and crystallization (2) from solutions of two salts by precipitation where the solubility of the salt formed is slight (e.g., silver nitrate solution plus sodium chloride solution yields silver chloride precipitate [almost all as sulid], and sodium nitrate present in solution as sodium cations and nitrate anions [recoverable as sodium nitrate, solid by separation of silver chlondc and subsequent evaporation of the solution]) (3) from fusion of a basic oxide (or its suitable compound—sodium carbonate above) and an acidic oxide (or its suitable compound—ammonium phosphate), since ammonium and hydroxyl are volatilized as ammonia and water. Thus, sodium ammonium hydrogen phosphate... 

The method given above is, of course, applicable to the detection of either saccharin or its compounds, of which the most commonly used are the sodium, ammonium and magnesium derivatives. 

The ammonium theory.—In the ammonium theory of H. Davy, A. M. Ampere, and J. J. Berzelius, it was assumed. that the ammonium compounds contain a metallic radicle, NH4 (4.31,38), which may replace potassium, sodium, etc., in different salts. When ammonia unites with hydrogen chloride, the NH4-radicle is formed which unites with chlorine to form ammonium chloride in the same way that potassium united with chlorine forms potassium chloride. The ammonium theory thus corresponds with the ethyl theory of J. J. Berzelius, and J. von Liebig. The nitrogen is assumed to be quinquevalent, and this is in harmony with the work of V. Meyer and M. T. Lecco, A. Ladenburg, and W. Lossen on the quaternary ammonium baseb, and with the isomorphism of the ammonium and the potassium salts. 

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