Estimation of Sodium

In another situation, a known excess quantity of standard iodine solution is added in the substance (a reducing agent) to be assayed and then the excess iodine may be titrated with the help of standard sodium thiosulphate solution, such as the estimation of sodium bisulphite ... 

For the estimation of sodium peroxide, Niemeyer14 recommends titration with standard potassium permanganate in presence of sulphuric acid ... 

The sulphur is obtained in a weighable form, and Sinnatt6 advocates the estimation of sodium hyposulphite by this method. 

The salts of sodium react with a solution of potassium nitrite and the nitrates of bismuth and caesium, yielding a yellow, crystalline precipitate of the formula 5Bi(N02)3,9CsN02,6NaN02. This reaction is applicable to the detection and estimation of sodium.2... 

Estimation of sodium, potassium and calcium ions and Na -K, Mg, Ca ATPases... 

The B.P, method for the estimation of sodium salicylate, C7H503Na, Mol. Wt. 160-1, is the same as for sodium benzoate (p. 125) and is a modification of Henville s method, using bromophenol blue instead of methyl orange. 1 ml 0-5N 0-08005 g. 

The estimation of sodium salicylate by the determination of the alkalinity of its ash was shown by Harrison and Carter to be inaccurate when the ash... 

Usually prepared by the action of NaCN on benzaldehyde in dilute alcohol. It is oxidized by nitric acid to benzil, and reduced by sodium amalgam to hydrobenzoin PhCHOHCHOHPh by tin amalgam and hydrochloric acid to des-oxybenzoin, PhCH2COPh and by zinc amalgam to stilbene PhCH = CHPh. It gives an oxime, phenylhydrazone and ethanoyl derivative. The a-oxime is used under the name cupron for the estimation of copper and molybdenum. 

C12H9N3O4. A brownish-red powder, soluble in sodium hydroxide. Used for the detection and estimation of magnesium, with which it forms a blue lake in alkaline solutions. 

An indirect estimate of surface tension may be obtained from the change in lattice parameters of small crystals such as magnesium oxide and sodium chloride owing to surface tensional compression [121] however, these may represent nonequilibrium surface stress rather than surface tension [68]. Surface stresses may produce wrinkling in harder materials [122]. 

Sodium thiosulphate is an important reducing agent used in volumetric analysis for the estimation of iodine ... 

Addition of calcium nitrate solution to a fluoride gives a white precipitate of calcium fluoride, CaFj. If the latter is precipitated slowly, it can be filtered off and weighed to estimate the fluoride. Fluoride can also be determined by the addition of sodium chloride and lead nitrate which precipitate lead chlorofluoride, PbClF. This is filtered off and weighed. 

Note. (1) Most sulphur compounds are completely oxidised if the tube is heated under the conditions described for the estimation of halogens. Sul-phonic acids and sulphones are more difficult to oxidise completely and the tube should be slowly heated to 300 and maintained at this temperature for at least 6 hours. The oxidation may be facilitated by adding a few crystals of sodium or potassium bromide to the organic material in the small tube, so that bromine shall be present to intensify the oxidation during the heating. 

Into a 750 ml. round-bottomed flask furnished with a reflux condenser place a solution of 34 g. (18-5 ml.) of concentrated sulphuric acid in 100 ml, of water add 33 g. of di-n-butyl cyanamide and a few fragments of porous porcelain. Reflux gently for 6 hours. Cool the resulting homogeneous solution and pour in a cold solution of 52 g. of sodium hydroxide in 95 ml. of water down the side of the flask so that most of it settles at the bottom without mixing with the solution in the flask. Connect the flask with a condenser for downward distillation and shake it to mix the two layers the free amine separates. Heat the flask when the amine with some water distils continue the distillation until no amine separates from a test portion of the distillate. Estimate the weight of water in the distillate anp add about half this amount of potassium hydroxide in the form of sticks, so that it dissolves slowly. 

Analysis. Dilute aqueous solutions of hydroxyhydroquiaone turn blue-green temporarily when mixed with ferric chloride. The solutions darken upon addition of small amounts, and turn red with additions of larger amounts of sodium carbonate. Derivatives used for identification are the picrate, which forms orange-red needles (mp of 96°C), and the triacetate (mp 96—97°C). Thin-layer chromatography and Hquid chromatography are well suited for the quahtative and quantitative estimation of hydroxyhydroquiaone (93,94). 

Production figures for sodium alumiaate are not released by manufacturers ia the United States. There are approximately eight commercial U.S. producers and total production was estimated at 120,000 metric tons ia 1990. Prices for large quantities of sodium alumiaate are ia the range of 0.22/kg to 0.43/kg for Hquids, depending upon concentration, location, and volume purchased. 

Alkali sihcates are used as components, rather than reactants, in many appHcations. In many cases they only contribute partially to overall performance. Utility factors are generally not as easy to identify. Their benefit usually depends on the surface and solution chemical properties of the wide range of highly hydrophilic polymeric siUcate ions deUverable from soluble sihcate products or their proprietary modifications. In most cases, however, one or two of the many possible induences of these complex anions cleady express themselves in final product performance at a level sufficient to justify their use (102). Estimates of the 1995 U.S. consumption of sodium sihcates are shown in Table 6. 

U.S. sodium bromide demand accounts for 8—10% of total bromine production. In 1994 demand is estimated to have been 13,600—17,200 metric tons (5). At mid-1996, the price for technical-grade sodium bromide iu tmckload quantities was 1.54/kg ( 0.70/lb) (6). Manufacturers of sodium bromide iuclude Albemarle, Great Lakes Chemical, Rhc )ne-Poulenc, and Whittaker Corporation. 

Economic Aspects and Uses. Production and sales values for high purity sodium hydrosulfide are Hsted ia Table 1. These figures exclude the low purity material produced by oil refiners, beHeved to be sold primarily to pulp mills. Estimates of uses of NaHS ia the United States for 1994 are as shown (3,4) ... 

Economic Aspects and Uses. Production and pricing information for Na2S through 1991 are Hsted in Table 2. U.S. production of sodium sulfide increased rapidly from 1965 through 1972 and then began to decrease. The last year that the U.S. Bureau of the Census released official production figures was in 1974 because at that time there were only three producers of sodium sulfide. Estimates indicate that 1991 production fell to the levels of the late 1950s. List prices have increased since 1974 as sulfur and sodium hydroxide prices have increased. 

Economic Aspects. U.S. production of sodium metabisulfite is estimated to be well ia excess of 45,000 t, but statistics are confused by some commingling with sodium sulfite. The principal U.S. producers are Rhc ne-Poulenc and General Chemical. The price ia mid-1995 was 0.63/kg for anhydrous sodium bisulfite. 

Economic Aspects. U.S. capacity for production of merchant sodium dithionite (soHds basis) was estimated at 93,000 metric tons in 1994. There are three North American producers of sodium dithionite. Hoechst Celanese is the largest producer (68,000 tons capacity) with two formate production locations and one zinc process location. Olin (25,000 t capacity) produces solution product only at two locations using both the amalgam and electrochemical processes. In 1994, Vulcan started a small solution plant in Wisconsin using the Olin electrochemical process. In addition, it is estimated that 13,000 t/yr is produced at U.S. pulp mills using the Borol process from sulfur dioxide and sodium borohydride. Growth is estimated at 2—3%/yr. The... 

A study of the North American bleaching agent market was completed in June 1988 and includes consumption quantities for the year 1986 (156). Chlorine consumption for 1986 was 1.86 x 10 t. The North American consumption volume of other chlorine-containing bleaching compounds including sodium and calcium hypochlorite, chlorinated isocyanurates, and hydantoins was 286,000 t. The 1986 North American consumption of sodium chlorate was estimated at 5.5 x 10 t. 

The specific use appHcations of sodium chlorite varies from country to country. Important factors are the regulatory and environmental laws in effect for air and water quaUty standards. Sodium chlorite is generally priced at about four to six times the cost of sodium chlorate. The Hst price of 80% technical-grade NaC102 in January 1991 was 2.65/kg (146). In 1990, the estimated consumption of sodium chlorate for the production of sodium chlorite in Canada was about 2700 metric tons and about 9100 metric tons in the United States (74). In Western Europe, the 1990 chlorate consumption estimate was about 11,000 metric tons. A summary of 1991 U.S. and foreign sodium chlorite producer annual plant capacities in various world market areas is given in Table 3. 

The prices of some important chromium chemicals are given ia Table 4, and production and shipment data for sodium chromate and dichromate are given ia Table 5. Data for the productioa and shipment of chromic acid have not been available siace 1972. However, traditionally CrO has held at about 30—35% of sodium dichromate production. The estimated capacity for domestic production of sodium dichromate is 150,000 to 200,000 t/yr. 

Estimates of various uses for hydrogen cyanide in the United States ate adiponitrile for nylon, 41% acetone cyanohydrin for acryhc plastics, 28% sodium... 

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