Sodium fluoride, oxidation state

Meyer H.Wehrli, Helv 20, 353(1937) CA 31, 5807(1937) 5)M.L.Wolfrom et al, JACS 65, 2084(1943) 6)M.L.Wolfrom et al, Ohio State Univ Final Rept, Project 459, Columbus, Ohio(Jan 1953)pp 1,3 34 Nitrated Deacetylated Chitine A wh flocculent ppt contg 11=6 to 11,9% nitrate N(as detd by DuPont nitrometer obtd by Wolfrom et al(Ref 3) by nitrating deacetylated chitin with 100% HNOj. The nitrated product represented the combined nitrate salt nitrate ester of deacetylated chitin. This substance contd one nitric acid salt unit per anhydro-o-glucosamine unit and 1.60-1.65 nitrate ester unit per anhydro-o-glucosamine anhydro -N-acetyl-D -glucosammine units. Attempts to nitrate deacetylated chitin by means of nitrogen pent oxide, in a non-aqueous medium y in the presence of sodium fluoride, by the method of Caesar(Ref 2) were unsuccessful mainly because of occlusion of NaF in the nitrated products(Ref 3)... 

Aluminum occurs widely in nature in silicates such as micas and feldspars, complexed with sodium and fluorine as cryolite, and in bauxite rock, which is composed of hydrous aluminum oxides, aluminum hydroxides, and impurities such as free silica (Cotton and Wilkinson 1988). Because of its reactivity, aluminum is not found as a free metal in nature (Bodek et al. 1988). Aluminum exhibits only one oxidation state (+3) in its compounds and its behavior in the environment is strongly influenced by its coordination chemistry. Aluminum partitions between solid and liquid phases by reacting and complexing with water molecules and anions such as chloride, fluoride, sulfate, nitrate, phosphate, and negatively charged functional groups on humic materials and clay. 

For the analysis of molybdenum, the sample is decomposed by fuming with a few drops of nitric acid and sulfuric acid in a platinum crucible and the molybdenum is determined gravimetrically7 as the 8-quinolinol complex. From the filtrate, potassium is determined gravimetrically as K2S04. Fluoride is determined by titration with a standard solution of thorium nitrate using sodium alizarinsulfonate as indicator, after steam distillation of fluorosilicic acid.8 The determination of the oxidation state of molybdenum is carried out by oxidizing a known amount of the compound with a known amount of potassium dichromate in hot 2 N sulfuric acid and titrating the excess dichromate with standard Fe2+ solution. 

The active ingredient is sodium pyrophosphate (Na4P20ylO H2O). For reduction of Tc-pertechnetate to lower oxidation states, tin(II) chloride or tin(II) fluoride is used. An optimal ratio of reducing agent/pyrophosphate must be maintained to prevent Tc-Sn-colloid formation (Srivastava et al. 1977). Technical problems with kit production have been reported (Kowalsky and Dalton 1981). 

The active ingredients are diphosphonic acids - dicarboxypropane diphosphonic acid (DPD), hydroxymethylene diphosphonic acid (HDP or HMDP), hydroxyethylidene diphosphonic acid (EHDP), methylene diphosphonic acid (MDP) - or their sodium salts. As stabilizers are used N-(4-aminobenzoyl)-L-glutaminic acid, gentisic acid (2,5-dihydroxybenzoic acid), ascorbic acid, or carbamide. For reduction of Tc-pertechne-tate to lower oxidation states, tin(II) chloride and tin(II) fluoride are employed. 

Consider the reaction between sodium metai and fluorine (F2) gas to form sodium fluoride. Using oxidation states, how many electrons would each sodium atom iose, and how many eiectrons would each fluorine atom gain How many sodium atoms are needed to react with one fluorine molecule Write a baianced equation for this reaction. 

An early conventional method for plutonium analysis was coprecipitation in acid solution with a rare earth fluoride, dissolution in aluminum nitrate solution with sodium nitrite to maintain the 4-4 oxidation state, and extraction into thenoyl-trifluoroacetone (TTA) in benzene. Plutonium was back-extracted into dilute HCl, the acid was evaporated, and plutonium was taken up in HCI-NH4CI solution... 

Fluorine compounds are widely used in industry. Large quantities of fluorspar, Cap2, are required as flux in steel manufacture. Synthetic and natural cryolite, NajAlFg, is used as a solvent for aluminum oxide in the electrolytic preparation of aluminum metal. Sodium fluoride is added to water to help prevent tooth decay, a measure that is commonly called water fluoridation. World reserves of high-grade fluorspar are adequate for several decades with about 13% of the production in the United States. A great deal of by-product fluorine is recovered from the processing of fluorapatite, Ca5(P04)3F, which is used as a source of phosphorus. 

The book by Prof. Yanko [1] discusses a mechanism of degradation of the flue walls, stating that the main corrosion agents are aluminium fluoride and sodium fluoride. The temperature of evaporation of aluminium fluoride is - 950 °C, while the temperature of evaporation of sodium fluoride is - 1,050 °C. Volatile sodium and aluminium fluoride penetrate the permeable pores of refractory [1] and interact with silica, giving volatile silicon tetrafluoride, while sodium oxide is released in the pores ... 

Modem refining technology uses tantalum and niobium fluoride compounds, and includes fluorination of raw material, separation and purification of tantalum and niobium by liquid-liquid extraction from such fluoride solutions. Preparation of additional products and by-products is also related to the treatment of fluoride solutions oxide production is based on the hydrolysis of tantalum and niobium fluorides into hydroxides production of potassium fluorotantalate (K - salt) requires the precipitation of fine crystals and finishing avoiding hydrolysis. Tantalum metal production is related to the chemistry of fluoride melts and is performed by sodium reduction of fluoride melts. Thus, the refining technology of tantalum and niobium involves work with tantalum and niobium fluoride compounds in solid, dissolved and molten states. 

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)... 

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