Sodium nitrate determination

Sodium Nitrate.- Determine moisture and chlorine by the usual methods, and the total, NaNO 3, by means of nitrometer-0.45 grm. is a very convenient quantity to work on (gives about 123 c.c. gas) grind very fine, and dissolve in a very little hot water in the cup of the nitrometer use about 15 c.c. concentrated H 2 SO 4. One cubic cent, of NO equals. 003805 grm. of NaNO 3. The insoluble matter, both organic and inorganic, should also be determined, also sulphate of soda and lime tested for. 

Black Powder. Black powder is mainly used as an igniter for nitrocellulose gun propellant, and to some extent in safety blasting fuse, delay fuses, and in firecrackers. Potassium nitrate black powder (74 wt %, 15.6 wt % carbon, 10.4 wt % sulfur) is used for military appHcations. The slower-burning, less cosdy, and more hygroscopic sodium nitrate black powder (71.0 wt %, 16.5 wt % carbon, 12.5 wt % sulfur) is used industrially. The reaction products of black powder are complex (Table 12) and change with the conditions of initia tion, confinement, and density. The reported thermochemical and performance characteristics vary greatly and depend on the source of material, its physical form, and the method of determination. Typical values are Hsted in Table 13. 

Preceding papers. h Preliminary values obtained through redetermination of parameters in crystals (cal-cite and sodium nitrate) by Mr. Norman Elliot. The values in parentheses are based on older parameter determinations. c L. Pauling and L. O. Brockway, Proc. Nat. Acad. Sci., 20, 336 (1934). The value 1.25 A. reported in crystals of oxalic acids and oxalates is probably less reliable. 

Comparison of the limiting viscosity numbers determined in deionized water with those determined in 1 molar sodium nitrate shows a 20 per cent decrease in copolymer intrinsic viscosity in the saline solution. These results are consistent with previous studies using aqueous saline solutions as theta solvents for 2-propenamide polymers(47) Degree of hydrolysis controls the value of limiting viscosity number for the hydrolyzed copolymers in distilled water. 

Example Feasible Region Determination and Rescaling. McLean and Anderson (9) described a mixture experiment in which magnesium (X ), sodium nitrate (X2), strontium nitrate (X3), and binder (X ) were combined and ignited to produce flares varying in intensity. The four components had the following ranges ... 

Other analytical assays proposed for the quantification of hydrolyzable tannins in plant materials include the rhodanine assay for the estimation of gallotannins (Berardini and others 2004) and sodium nitrate for the quantitative determination of ellagic acid (Wilson and Flagerman 1990). 

Ke and Regier [71] have described a direct potentiometric determination of fluoride in seawater after extraction with 8-hydroxyquinoline. This procedure was applied to samples of seawater, fluoridated tap-water, well-water, and effluent from a phosphate reduction plant. Interfering metals, e.g., calcium, magnesium, iron, and aluminium were removed by extraction into a solution of 8-hydroxyquinoline in 2-butoxyethanol-chloroform after addition of glycine-sodium hydroxide buffer solution (pH 10.5 to 10.8). A buffer solution (sodium nitrate-l,2-diamino-cyclohexane-N,N,N. AT-tetra-acetic acid-acetic acid pH 5.5) was then added to adjust the total ionic strength and the fluoride ions were determined by means of a solid membrane fluoride-selective electrode (Orion, model 94-09). Results were in close agreement with and more reproducible than those obtained after distillation [72]. Omission of the extraction led to lower results. Four determinations can be made in one hour. 

To date, a few methods have been proposed for direct determination of trace iodide in seawater. The first involved the use of neutron activation analysis (NAA) [86], where iodide in seawater was concentrated by strongly basic anion-exchange column, eluted by sodium nitrate, and precipitated as palladium iodide. The second involved the use of automated electrochemical procedures [90] iodide was electrochemically oxidised to iodine and was concentrated on a carbon wool electrode. After removal of interference ions, the iodine was eluted with ascorbic acid and was determined by a polished Ag3SI electrode. The third method involved the use of cathodic stripping square wave voltammetry [92] (See Sect. 2.16.3). Iodine reacts with mercury in a one-electron process, and the sensitivity is increased remarkably by the addition of Triton X. The three methods have detection limits of 0.7 (250 ml seawater), 0.1 (50 ml), and 0.02 pg/l (10 ml), respectively, and could be applied to almost all the samples. However, NAA is not generally employed. The second electrochemical method uses an automated system but is a special apparatus just for determination of iodide. The first and third methods are time-consuming. 

Buchberger et al. [104] carried out a selective determination of iodide in brine. The performance of a potentiometric method using an ion-selective electrode and of liquid chromatography coupled with ultraviolet detection at 230 nm were compared as methods for the determination of iodide in the presence of other iodide species. Satisfactory results were obtained from the potentiometric method provided the solution was first diluted tenfold with 5 M sodium nitrate, and external standards were used. Better reproducibility was, however, achieved with HPLC, provided precautions were taken to prevent reduction of iodine to iodide in the mobile phase, for which extraction of iodine with carbon tetrachloride prior to analysis was recommended. This was the pre-... 

Campbell and Ottaway [136] also used selective volatilisation of the cadmium analyte to determine cadmium in seawater. They could detect 0.04 pg/1 cadmium (2pg in 50 pi) in seawater. They dried at 100 °C and atomised at 1500 °C with no char step. Cadmium was lost above 350 °C. They could not use ammonium nitrate because the char temperature required to remove the ammonium nitrate also volatilised the cadmium. Sodium nitrate and sodium and magnesium chloride salts provided reduced signals for cadmium at much lower concentrations than their concentration in seawater if the atomisation temperature was in excess of 1800 °C. The determination required lower atomisation temperatures to avoid atomising the salts. Even this left the magnesium interference, which required the method of additions. 

The same reaction can be applied, not only to the aromatic parent substances, the hydrocarbons, but also to all their derivatives, such as phenols, amines, aldehydes, acids, and so on. The nitration does not, however, always proceed with the same ease, and therefore the most favourable experimental conditions must be determined for each substance. If a substance is very easily nitrated it may be done with nitric acid sufficiently diluted with water, or else the substance to be nitrated is dissolved in a resistant solvent and is then treated with nitric acid. Glacial acetic acid is frequently used as the solvent. Substances which are less easily nitrated are dissolved in concentrated or fuming nitric acid. If the nitration proceeds with difficulty the elimination of water is facilitated by the addition of concentrated sulphuric acid to ordinary or fuming nitric acid. When nitration is carried out in sulphuric acid solution, potassium or sodium nitrate is sometimes used instead of nitric acid. The methods of nitration described may be still further modified in two ways 1, the temperature or, 2, the amount of nitric acid used, may be varied. Thus nitration can be carried out at the temperature of a freezing mixture, at that of ice, at that of cold water, at a gentle heat, or, finally, at the boiling point. Moreover, we can either employ an excess of nitric acid or the theoretical amount. Small scale preliminary experiments will indicate which of these numerous modifications may be expected to yield the best results. Since nitro-compounds are usually insoluble or sparingly soluble in water they can be precipitated from the nitration mixture by dilution with water. 

Minimum impact energies to initiate the explosion of various exothermic mixtures, used for the continuous casting of steel, were determined. Components used included sodium nitrate, aluminium-iron scale, silicocalcium, ferrosilicon fluorspar, borax, etc. Hazardous mixtures were defined, and improved safety controls were derived. 

Other oxidizers, including barium chromate (BaCrO,), lead chromate (PbCrO 4), sodium nitrate (NaNO 3), lead dioxide (PbO 2), and barium peroxide (BaO 2) will also be encountered in subsequent chapters. Bear in mind that reactivity and ease of ignition are often related to the melting point of the oxidizer, and the volatility of the reaction products determines the amount of gas that will be formed from a given oxidizer /fuel combination. Table 3.2 contains the physical and chemical properties of the common oxidizers, and Table 5.8 lists the melting and boiling points of some of the common reaction products. 

Here/w stands for the electron fraction of water in the solution. Thus the electron fraction of the solute is/s = 1 —fw- In addition, G(HN02), G(H2), and G(02) are G-values of HNO2, H2, and O2 formation, respectively, experimentally determined in the solution. Reported G(H2) and G(02) in nitric acid and sodium nitrate solutions are summarized in Fig. 9 [127]. 

The Pb(II)/Pb(Hg) electrode process has been analyzed using digital simulation and the results have been compared with experiments carried out in aqueous sodium nitrate solutions applying convolution/deconvolution voltammetry to determine charge-transferrate constants and transfer coefficients [41]. Principles of thin-layer anodic stripping voltammetry have been discussed and a model for the stripping step has been proposed. 

The values agree well in position with those of Woldbye (17) (which were for solutions M in sodium nitrate), but our extinction coefficients are consistently about 10% higher than his. In addition, we note a weak maximum for T at 330 m/i and report some information on the spectra in the doublet region. These last measurements were made on filtered 0.04M solutions, using 5 cm. cells. The general absorption curves were obtained by a Cary Model 14 spectrophotometer, but for most of the kinetic studies and analytical measurements, optical densities at selected wave lengths were determined by a DU Beckman spectrophotometer. 

The terminal numbers with potassium, rubidium, and csesium nitrates represent the b.p. of sat. soln. at nearly normal press. for sodium nitrate the corresponding value is 67 6 (119°). Determinations of the solubility of sodium nitrate have been made by G. J. Mulder, Earl of Berkeley, A. Ditte, L. Maumene, A. fitard, etc.30 The solubility curve of sodium nitrate has been carried upwards 781 (180°), 83 5 (220°), 915 (225°), and 100 (313°), the last-named temp, represents the m.p. of the salt. According to L. C. de Coppet, the eutectic or cryohydric temp, of sodium nitrate is —18"5°, and the eutectic mixture is not a definite hydrate, NaN03.7H20, as A. Ditte once supposed. A. fitard represents the solubility S... 

Rogers and Harrison [103] tried to determine the conditions governing this phenomenon, i.e. the explosion during the growth of /Mead azide. Their experiments, which are illustrated diagrammatically in Fig. 46, were carried out in a test-tube. Three solutions were carefully introduced so that they did not mix. The bottom layer consisted of 20% lead nitrate (2 cm3). The middle layer was 20% sodium nitrate (1 cm3). The top layer was 10% sodium azide (2 cm3). Crystals of lead azide formed in the sodium nitrate layer after ihr. They appeared to start from the walls and spread inwards. A major explosion generally occurred in the system after the crystals had been growing for 6-12 hr. A series of very small explosions accompanied by clicks sometimes preceded the major explosion. 

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