Specific gravity sodium hydroxide

Procedures for determining the quaUty of formaldehyde solutions ate outlined by ASTM (120). Analytical methods relevant to Table 5 foUow formaldehyde by the sodium sulfite method (D2194) methanol by specific gravity (D2380) acidity as formic acid by titration with sodium hydroxide (D2379) iron by colorimetry (D2087) and color (APHA) by comparison to platinum—cobalt color standards (D1209). 

What s the density of sodium hydroxide You ve just done a wash with 5-10% sodium hydroxide solution, you ve just read something about finding various layers in the funnel by their densities, and, by this question, you ve just shown that you ve missed the point. Most wash solutions are 5 to 10% active ingredient dissolved in water. This means they are 90 to 95% water. Looking up the density of the solid reagents then, is a waste of time. The density of these solutions is very close to that of water. (10% NaOH has a specific gravity of 1.1089.)... 

Sodium iodate dissolves copiously in warm dil. sulphuric acid without decomposition but it is decomposed by hydrochloric acid. The presence of potassium iodide causes potassium iodate to dissolve more readily than in pure water and although A. Ditte says that a double salt is not obtained from the soln., yet the phenomenon is probably due to the formation of a complex salt in soln. J, N. Bronsted measured the solubility of potassium iodate in aq. soln. of potassium hydroxide. Potassium iodate does not dissolve in alcohol. According to H. L. Wheeler, 100 grms. of water at 23° dissolve 21 grms. of rubidium iodate, and 26 grms. of caesium iodate at 24°. The specific gravity of a sat. aq. soln. of lithium iodate 52 at 18° is 1 568 thesp. gr. of soln. of potassium iodate calculated by G. T. Gerlach. from P. Kremers data, are ... 

Table VI.—Per Cent, of NaOH in Solutions of Sodium Hydroxide of Specific Gravity l-00 to 1 53 at 15° (Water at 4° Unity).

Table VII.—The Specific Gravities of Solutions of Sodium Hydroxide at...

From the nitration of metriol monoacetate metriol acetate-dinitrate is formed as an oily liquid of specific gravity d25 = 1.362. Cautious hydrolysis of this substance in contact with sodium hydroxide solution in ethanol at room temperature produces trimethylolethane dinitrate with a yield of 75%. 

Methoxyl analyses are most conveniently carried out with large samples (2 to 3 g.). The sample is hydrolyzed in a sodium hydroxide solution, and the methanol is fractionally distilled into a tared receiver.4 From the weight and specific gravity of the distillate the percentage of methoxyl group may be calculated.6,6... 

Assay The specific gravity of a sample, determined by any reliable method (see General Provisions), is not greater than 0.8096 at 25725° (equivalent to 0.8161 at 15.56715.56°). Acidity Transfer 10 mL of sample to a glass-stoppered flask containing 25 mL of water, add 0.5 mL of phenolphthalein TS, and then add 0.02 N sodium hydroxide to the first appearance of a pink color that persists after shaking for 30 s. Add 25 mL of sample, mix, and titrate with 0.02 N sodium hydroxide until the pink color is restored. Not more than 0.5 mL of 0.02 N sodium hydroxide is required to restore the pink color. 

Resin Preparation. All phenolic resins were prepared in the laboratory. Resin preparations were replicated one time. To prepare each resin, all phenol and water were placed in a reaction kettle. The formaldehyde was added in three steps 1) total formaldehyde less 1 mole of formaldehyde was added at the beginning 2) the balance was divided into two equal parts (i.e., 0.5 mole each), one of which was added 1 hour after the reaction began and 3) the remainder of formaldehyde was added 20 minutes later. The sodium hydroxide was added as catalyst in four steps (i.e., four equal parts at 10-minute intervals). To initiate the reaction, the mixture was heated and maintained at 75 °C. All reactions were terminated at the end of 100 minutes. Gel time, pH, viscosity, solid content, and specific gravity were determined. The general conditions for resin preparation were ... 

Molar Ratios of Sodium Hydroxide/Phenol. Table II summarizes the effect of varying molar ratios of NaOH/phenol on pH, viscosity, solid content, specific gravity, gel time, and molecular weight of the resins. The GPC chromatograms of the phenolic resins reacted at different NaOH/phenol ratios are given in Figure 4. 

In addition to the method described, which is the one commonly used, the reduction can also be effected with iron shavings. This method, however, is difficult to carry out. There is also the electrolytic method in which nitrobenzene, in suspension in sodium hydroxide solution, is reduced to l drazobenzene at the cathode. So far as is known, this method is used only by the GeseUschaft fur Chemische Industrie in Basel. It does not require zinc dust and gives good yields. The best results are obtained when the specific gravity of the hydroxide solution equals that of m trobenzene. 

One of the most important developments in the field of hydrometallurgy has been the application of elevated pressures and temperatures to complex sulfide and oxide ores (B21, F8, G8, M5, M6). The pressure-leaching of bauxite ores by the Bayer process (E3) is probably the first successful commercial application of this technique. The bauxite ore is leached with sodium hydroxide solution with a specific gravity of 1.36-1.4 at 160-170°C for 1 2 hr under a working pressure of 100 psig. The alumina is produced by calcining the aluminum hydrate precipitated from the leach liquor. 

Properties o the alkali hydroxides.—The alkali hydroxides are brittle, white, translucent solids with a more or less crystalline fracture, and fibrous texture. Sodium hydroxide deliquesces on exposure to the air, but it goes solid again owing to the formation of the carbonate by the absorption of carbon dioxide from the air. Lithium hydroxide is a little hygroscopic. Potassium hydroxide is even more deliquescent than the sodium compound but its carbonate is also deliquescent. The hydroxides are very soluble in water, and they also dissolve in alcohol. The reported numbers for the specific gravities of sodium hydroxide range from 1 723 to 2T30 and for potassium hydroxide, from 1 958 to 2 6. The best representative sp. gr. are 2 54 for lithium hydroxide 2 130 for sodium hydroxide 2 044 for potassium hydroxide 3 203 (11°) for rubidium hydroxide and 3 675 (11°) for cjesium hydroxide. 

The test device for specific gravity consists of an absorbent cellulose pad impregnated with bromthymol blue, poly-methylvinyi ether and/or maleic anhydride, and sodium hydroxide. The test depends on the apparent pK change of the pretreated polyelectrolyte in relation to ionic strength the hydrogen ions released are detected by the pH indicator. The color changes from a dark blue at a low specific gravity... 

The average current efficiency of the Nelson cell is to be considered as 86 per cent, and the chemical efficiency rated at 80 per cent. All but 2 per cent of the sodium chloride is to be considci ed as recoverable. The Nelson cell is to operate under optimum conditions on a 26.4 per cent sodium chloride solution at 55 0, producing a solution of specific gravity 1.23 and containing 9.67 per cent sodium hydroxide and 14.52 per cent residual sodium chloride. 

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