Sodium applications

Regardless of sodiums applications in industry, the most important fact about sodium is that it is an element essential to health in humans and other higher animals. The sodium ion (Na+) is present in greatest concentration in the fluids that are outside the cells of animals (potas-... 

Sodium is an indispensable element for some crops (notably sugar beet), can partially substitute for potassium in several crops, contributes to neutralizing soil and subsoil acidity, and has a positive effect on soil phosphorus solubility. Sodium is an essential nutrient for cattle, and sodium application to soil increases its content in pastures. Sodium nitrate is particularly effective as a nitrogen source for sugar beet, vegetable crops, tobacco, and cotton (qv), and for any crop in acid soils. 

Sodium (in compound form) is sometimes applied to grazed swards in an attempt to improve palatability and intake. Sodium application can also reduce the risk from grass staggers in some situations. 

As an example of the application of the method, Neumann and Tanner [54] followed the variation with time of the surface tension of aqueous sodium dode-cyl sulfate solutions. Their results are shown in Fig. 11-15, and it is seen that a slow but considerable change occurred. 

A selection of important anionic surfactants is displayed in table C2.3.1. Carboxylic acid salts or tire soaps are tire best known anionic surfactants. These materials were originally derived from animal fats by saponification. The ionized carboxyl group provides tire anionic charge. Examples witlr hydrocarbon chains of fewer tlran ten carbon atoms are too soluble and tliose witlr chains longer tlran 20 carbon atoms are too insoluble to be useful in aqueous applications. They may be prepared witlr cations otlrer tlran sodium. 

The reaction with sodium is by no means an infallible practical test for alcohols since, strictly speaking, it is applicable only to pure anhydrous liquids. Traces of water, present as impurities, would give an initial evolution of hydrogen, but reaction would stop after a time if an alcohol is absent furthermore, certain esters and ketones also evolve hydrogen when treated with sodium (compare Section XI,7,6). It may, however, be assumed that if no hydrogen is evolved in the test, the substance is not an alcohol. 

The method is generally applicable when other modes of esterification are either slow, inefficient, or likely to cause isomerisation it is, however, time-consuming and expensive. Small quantities of acid impurities are sometimes produced, hence it is advisable to wash the ester with saturated sodium bicarbonate solution. The silver salt can usually be prepared by dissolving the acid in the calculated quantity of standard ammonium hydroxide solution and... 

The reaction is applicable to the preparation of amines from amides of aliphatic aromatic, aryl-aliphatic and heterocyclic acids. A further example is given in Section IV,170 in connexion with the preparation of anthranilic acid from phthal-imide. It may be mentioned that for aliphatic monoamides containing more than eight carbon atoms aqueous alkaline hypohalite gives poor yields of the amines. Good results are obtained by treatment of the amide (C > 8) in methanol with sodium methoxide and bromine, followed by hydrolysis of the resulting N-alkyl methyl carbamate ... 

In general, benzoylation of aromatic amines finds less application than acetylation in preparative work, but the process is often employed for the identification and characterisation of aromatic amines (and also of hydroxy compounds). Benzoyl chloride (Section IV, 185) is the reagent commonly used. This reagent is so slowly hydrolysed by water that benzoylation can be carried out in an aqueous medium. In the Schotten-Baumann method of benzoylation the amino compound or its salt is dissolved or suspended in a slight excess of 8-15 per cent, sodium hydroxide solution, a small excess (about 10-15 per cent, more than the theoretical quantity) of benzoyl chloride is then added and the mixture vigorously shaken in a stoppered vessel (or else the mixture is stirred mechanically). Benzoylation proceeds smoothly and the sparingly soluble benzoyl derivative usually separates as a solid. The sodium hydroxide hydrolyses the excess of benzoyl chloride, yielding sodium benzoate and sodium chloride, which remain in solution ... 

The experimental conditions necessary for the preparation of a solution of a diazonium salt, diazotisation of a primary amine, are as follows. The amine is dissolved in a suitable volume of water containing 2 5-3 equivalents of hydrochloric acid (or of sulphuric acid) by the application of heat if necessary, and the solution is cooled in ice when the amine hydrochloride (or sulphate) usually crystallises. The temperature is maintained at 0-5°, an aqueous solution of sodium nitrite is added portion-wise until, after allowing 3-4 minutes for reaction, the solution gives an immediate positive test for excess of nitrous acid with an external indicator—moist potassium iodide - starch paper f ... 

An interesting application of the diazo reaction is to the preparation of the otherwise difficultly accessible o- and />-dinitrobenzenes o- or p-rutrophenyl-diazonium fluoborates react with sodium nitrite in the presence of copper powder to yield o- or p-dinitrobenzene ... 

Oximes (compare Section III,74,B). The following procedure has wide application. Dissolve 0-5 g. of hydroxylamine hydrochloride in 2 ml. of water, add 2 ml. of 10 per cent, sodium hydroxide solution and 0-2 g. of the aldehyde (or ketone). If the latter is insoluble, add just sufficient alcohol to the mixture to give a clear solution. Heat the mixture under reflux for 10-15 minutes, and then cool in ice. If crystals separate, filter these off, and recrystallise from alcohol, dilute alcohol, benzene or light petroleum (b.p. 60-80°). If no solid separates on cooling, dilute with 2-3 volumes of water, filter the precipitated sohd, and recrystallise. 

Esters of dicarboxyUc acids having hydrogen on tbe 8 or e carbon atoms undergo intramolecular cyclisation when heated with sodium or with sodium ethoxide. This cyclisation is known as the Dieckmann reaction. It is essentially an application of the Claiseu (or acetoacetic eater) condensation to the formation of a ring system the condensation occurs internally to produce s... 

Potassium and sodium borohydride show greater selectivity in action than lithium aluminium hydride thus ketones or aldehydes may be reduced to alcohols whilst the cyano, nitro, amido and carbalkoxy groups remain unaffected. Furthermore, the reagent may be used in aqueous or aqueous-alcoholic solution. One simple application of its use will be described, viz., the reduction of m-nitrobenzaldehyde to m-nitrobenzyl alcohol ... 

The formation of alkylbenzenes, largely free from unaaturated compounds, provides another interesting application of organosodium compounds. Thus pure M-butylbenzene is readily obtained in good yield from benzyl sodium and n-propyl bromide. Benzyl-sodium is conveniently prepared by first forming phenyl-sodium by reaction between sodium and chlorobenzene in a toluene medium, followed by heating the toluene suspension of the phenyl-sodium at 105° for about 35 minutes ... 

Sodium terbium borate is used in solid-state devices. The oxide has potential application as an activator for green phosphors used in color TV tubes. It can be used with Zr02 as a crystal stabilizer of fuel cells which operate at elevated temperature. Few other uses have been found. 

Table 8 1 illustrates an application of each of these to a functional group transfer matron The anionic portion of the salt substitutes for the halogen of an alkyl halide The metal cation portion becomes a lithium sodium or potassium halide... 

The large rate enhancements observed for bimolecular nucleophilic substitutions m polai aprotic solvents are used to advantage m synthetic applications An example can be seen m the preparation of alkyl cyanides (mtiiles) by the reaction of sodium cyanide with alkyl halides... 

The most frequent applications of these procedures he in the preparation of terminal alkynes Because the terminal alkyne product is acidic enough to transfer a proton to amide anion one equivalent of base m addition to the two equivalents required for dou ble dehydrohalogenation is needed Adding water or acid after the reaction is complete converts the sodium salt to the corresponding alkyne... 

Saccharin was discovered at Johns Hopkins Uni versity in 1879 in the course of research on coal tar derivatives and is the oldest artificial sweetener In spite of Its name which comes from the Latin word for sugar saccharin bears no structural relationship to any sugar Nor is saccharin itself very soluble in wa ter The proton bonded to nitrogen however is fairly acidic and saccharin is normally marketed as its water soluble sodium or calcium salt Its earliest applications were not in weight control but as a... 

Standard polyester fibers contain no reactive dye sites. PET fibers are typically dyed by diffusiag dispersed dyestuffs iato the amorphous regions ia the fibers. Copolyesters from a variety of copolymeri2able glycol or diacid comonomers open the fiber stmcture to achieve deep dyeabiHty (7,28—30). This approach is useful when the attendant effects on the copolyester thermal or physical properties are not of concern (31,32). The addition of anionic sites to polyester usiag sodium dimethyl 5-sulfoisophthalate [3965-55-7] has been practiced to make fibers receptive to cationic dyes (33). Yams and fabrics made from mixtures of disperse and cationicaHy dyeable PET show a visual range from subde heather tones to striking contrasts (see Dyes, application and evaluation). 

W. J. O ReiUy and co-workers. Development of Sodium Chlorate Candles for the Storage and Supply of Oxygen for Space Exploration Applications, Rept. No. 69-4695, Air Research Corp., Los Angeles, Calif., July 1969. 

M. M. Cook and co-workers, "Sodium Borohydride Reductions—Novel Approaches to Decolorization and Metals Removal iu Dye Manufacturiug and Textile Effluent Applications," 203rd National Meeting of the American Chemical Society, San Erancisco, Apr. 5—10,1992. 

In comparison to N—S bond formation, O—N bond formation by essentially oxidative procedures has found few applications in the synthesis of five-membered heterocycles. The 1,2,4-oxadiazole system (278) was prepared by the action of sodium hypochlorite on A(-acylamidines (277) (76S268). The A -benzoylamidino compounds (279) were also converted into the 1,2,4-oxadiazoles (280) by the action of r-butyl hypochlorite followed by base. In both cyclizations A -chloro compounds are thought to be intermediates (76BCJ3607). 

---