Sodium and its compounds

Like lithium, sodium and its compounds have been studied extensively in solution in liquid NH3. Sodium metal in such solutions slowly or with catalysis forms the amide, NaNH2. The solution of the metal is a powerful... 

The student of Organic Chemistry will probably be impressed at an early stage with the importance of metallic sodium and its compounds in synthetic work, and will subsequently mark the value of such substances as acetoacetic-, malonic-, and cyanacetic-ester and their sodium compounds. 

Of the alkali metals lithium, sodium, potassium, rubidium and cesium, elemental sodium and its compounds are the most important industrially, particularly the mineral and industrial heavy chemicals sodium chloride, sodium carbonate, sodium hydroxide, sodium sulfate etc. In second place is potassium, which is as its salts (chloride, sulfate, nitrate, phosphate) an important component of mineral fertilizers. Lithium and its compounds have a much lower but steadily increasing importance. Cesium and rubidium are only utilized in very small quantities for special applications. 

Describe some uses for (a) lithium and its compounds and (b) sodium and its compounds. 

Obsolete uses of urea peroxohydrate, as a convenient source of aqueous hydrogen peroxide, include the chemical deburring of metals, as a topical disinfectant and mouth wash, and as a hairdresser s bleach. In the 1990s the compound has been studied as a laboratory oxidant in organic chemistry (99,100). It effects epoxidation, the Baeyer-Villiger reaction, oxidation of aromatic amines to nitro compounds, and the conversion of sodium and nitrogen compounds to S—O and N—O compounds. 

Thermodynamic data show that the stabilities of the caesium chloride-metal chloride complexes are greater than the conesponding sodium and potassium compounds, and tire fluorides form complexes more readily tlrair the chlorides, in the solid state. It would seem that tire stabilities of these compounds would transfer into tire liquid state. In fact, it has been possible to account for the heats of formation of molten salt mixtures by the assumption that molten complex salts contain complex as well as simple anions, so tlrat tire heat of formation of the liquid mixtures is tire mole fraction weighted product of the pure components and the complex. For example, in the CsCl-ZrCU system the heat of formation is given on each side of tire complex compound composition, the mole fraction of the compound... 

W. A. Hart and O. F. Beumel, Lithium and its compounds, Comprehen.tive Inorganic Chemistry. Vol. 1, Chap. 7, Pergamon Press, Oxford, 1973. T. P. Whaley, Sodium, potassium, rubidium, caesium and francium, ibid.. Chap. 8. 

Lithium resembles magnesium, and its compounds show covalent character. Sodium compounds are soluble in water, plentiful, and inexpensive. Potassium compounds are generally less hygroscopic than sodium compounds. 

Similar to the history of many other elements, iodine s discovery was serendipitous in the sense that no one was looking for it specifically. In 1811 Bernard Courtois (1777—1838), a French chemist, attempted to remove sodium and potassium compounds from the ash of burned seaweed in order to make gunpowder. After removing these chemicals from the ash, he added sulfuric acid (H SO j) to the remaining ash. However, he mistakenly added too much acid, which produced a violet-colored vapor cloud that erupted from the mixture. This violet vapor condensed on all the metallic objects in the room, leaving a layer of sohd black iodine crystals. Sir Humphry Davy (1778—1829) confirmed this discovery of a new element and named it iodine after the Greek word iodes, which means violet, but it was Courtois who was given credit for the discovery of iodine. 

Strontium and its compounds are mostly derived from celestite, SrS04. The mineral is converted to its carbonate by heating with sodium carbonate. Alternatively, the mineral may be reduced to sulfide by heating with coke. The carbonate or the sulfide is then converted to other strontium salts. 

A pulse polarographic method to determine dantrolene sodium and its major metabolites in urine after ethyl acetate extraction has been reported [181]. The ethyl acetate is brought to a residue and the dantrolene plus the total extract-able metabolites are analyzed for reduction of the azomethine linkage at -0.86 V in a DMF-acetate buffer (pH 4.0). The nitro compounds are simultaneously determined in the same media as dantrolene equivalents from the reduction of the nitro group at -0.26 V (see Fig. 26.13). The difference between the two determinations represents the metabolites not containing the nitro group. Levels as low as 0.1 fig/mL can be determined for either functional group. 

Chromates, Dichromates, Trichromates T etra-chromates. See p C274-Lff Chromic Acid. See p C298-R to C299-L Chromium and Its Compounds. See pp C300-Lff Diazonium compounds and sodium sulfides react vigorously and are known to explode. Similar explosive reactions have been observed with H2S, also (Refs 40 41)... 

CAUTION The toxicity of mercury is such that the element and its compounds should not be allowed to contaminate air or water. Wear eye protection, nitrile rubber gloves, and laboratory coat. Work in the fume hood. Dissolve the waste mercury salts (10 g) as far as possible in water (100 mL). Adjust the solution to pH 10 with 10% sodium hydroxide solution. Add 20% sodium sulfide solution while stirring until no further precipitation occurs. Withdraw a small sample of supernatant liquid and add sodium sulfide solution to check that precipitation is complete. Allow the precipitate to settle, and then decant or filter the supernatant liquid into the drain with at least 50 times its volume of water. Package the dry mercuric sulfide for disposal in a secure landfill.13-15... 

Retention Times and Relative Retention Times for Pantoprazole Sodium and its Related Compounds... 

Ores of arsenic orpiment, realgar, arsenolite, arsenopyrite. Compounds of arsenic arsine, arsenic trioxide, arsenious acid, cupric hydrogen arsenite, arsenic pentoxide, arsenic acid, sodium arsenate. The Marsh test for arsenic. U.ses of arsenic and its compounds lead shot, insecticides, weed killers, chemotherapy. 

Courtois and his father collected seaweed on the coasts of Normandy and Brittany in France. Then they burned it. Next, they soaked the seaweed ashes in water to dissolve the sodium and potassium compounds. Sulfuric acid was added to react with the unwanted seaweed chemicals. Finally, they allowed the water to evaporate, leaving the compounds behind. These compounds are white crystals, much like ordinary table salt. The compounds were sold to large industrial businesses for use in such products as table salt and baking soda. 

They note (21), "Considerable development work remains before an integrated process could be demonstrated. Questions include materials of construction to withstand the severe corrosion during the calcination step and the reduction step. Methods of trapping the reduced sodium metal need to be devised. It was found that the nitrate level would have to be reduced to an undetermined low level (probably < 10% ) for a safe carbon reduction reaction. Thermal decomposition may have to be supplemented by chemical reduction to achieve this level. Excessive volatility of sodium and cesium compounds was observed during calcination. To this we add that no calculation of the costs of installing and operating such a sodium removal process has been made. 

The thiocyanate method has been used for determining niobium in steels [35,118], tantalum and its compounds [6,7,119], cobalt alloys [37], uranium [120], rocks and minerals [1,121], sodium metal [122], and thin Nb-Ti films [123]. Niobium has been determined in various metals and alloys with the use of Bromopyrogallol Red [124]. 

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