Neutral waters

Thiosulfates. The ammonium, alkaU metal, and aLkaline-earth thiosulfates are soluble in water. Neutral or slightly alkaline solutions containing excess base or the corresponding sulfite are more stable than acid solutions. Thiosulfate solutions of other metal ions can be prepared, but their stabiUty depends on the presence of excess thiosulfate, the formation of complexes, and the prevention of insoluble sulfide precipitates. 

Chemical Reactivity - Reactivity with Water Reacts vigorously with water to form highly flammable acetylene gas which can spontaneously ignite Reactivity with Common Materials Reacts with copper and brass to form an explosive formulation Stability During Transport Stable but in absence of water Neutralizing Agents for Acids and Caustics Not pertinent Polymerization Not pertinent Inhibitor of Polymerization Not pertinent. 

The following procedure is given in U.S. Patent 3,458,528 78 grams (0.675 mol) of 5-nitroimidazole is dissolved in 1,500 ml of acetic acid upon the addition of 72 ml (0.57 mol) of boron trifluoride etherate. 175 ml (3.5 mols) of ethylene oxide in 175 ml of hexane, in a dropping funnel topped with a cold finger, is added slowly over 1 hour to the above solution maintained at 32° to 35°C with a water cooling bath. The mixture is concentrated under high vacuum to 100 to 150 ml volume. The residue is diluted with 500 ml of water, neutralized to pH 7 with aqueous sodium hydroxide, and extracted with 1.5 liters of ethyl acetate. The extract is dried and evaporated to yield 1-(2 -hydroxyethyl)-5-nitroimidazole. 

To measure the amount of the enol-sulfate of coelenterazine in a tissue, the methanol homogenate prepared in Section C5.1 is centrifuged, and 10 pi of the supernatant is heated with 0.1 ml of 0.5 M HC1 at 95° C for one minute under argon gas, in order to hydrolyze the enol-sulfate group. The material is quickly cooled in ice water, neutralized with a small amount of solid NaHCO , and then the amount... 

Basically, most processes for the commercial production of PETN involve pouring PE into 98+% nitric acid (sp gr 1.50—1.52g/cc) at a temp not exceeding 25°. Since PETN is only slightly sol in nitric acid it ppts near the end of the nitration. The ppt is then filtered, washed with water, neutralized with Na2C03 soln, and recrystd from acet. In some processes the nitric acid is diluted with water after nitration. This is believed to keep some of the impurities in soln... 

Acid Manufacture. Relatively small mostly leakage plus drainings from air pollution abatement scrubbers. Also included are a) acid waters, neutralized with lime or soda ash b) sometimes azeotroping agents such as n-propyl acetate c) sometimes heavy metals from equipment corrosion and d) nitrobodies from acid recovery... 

BEET JUICE The soluble solids (and some fine particulates in suspension) extracted from beet cossettes (slices) by a countercurrent hot water (neutral or slightly alkaline pH) diffusion process. A small amount of soluble solids remains in the spent cossettes (or pulp). 

Tie has good resistance to sulfuric acid.l l A passivating oxide layer is formed up to a potential of 1.8 V at which point corrosion becomes severe. TiC is also very resistant to sea water, neutral industrial waste waters, and human sweat. Cr7C3 is even more corrosion resistant and is used extensively as a passivation interlayer. 

As in water, neutralization in all amphiprotic solvents represents the backward reaction of self-dissociation down to the equilibrium level of the ionic product in the pure solvent. 

Ethyl Benzyl Ether [Brpnsted Acid Promoted Reduction of an Aldehyde to an Unsymmetrical Ether].327 To a cooled mixture of benzaldehyde (4.3 g, 41 mmol) and absolute ethanol (3.7 g, 80 mmol) was added trichloroacetic acid (18.2 g, 111 mmol). Et3SiH (6.96 g, 60 mmol) was then added dropwise with stirring while the mixture was maintained at 50-60°. After 4 hours, the reaction mixture was diluted with water, neutralized with aqueous NaHC03 solution, and extracted with Et20. The dried ether extract was distilled and the 170-190° fraction was collected. Distillation from sodium gave ethyl benzyl ether 4.8 g (90%) bp 187-189°. 

In a synthesis similar to that depicted in Scheme 54, aminoesters 344 dissolved in DMF are treated with POCI3 and heated at 50-60 °C for 2h. The simple work-up procedure involves pouring into ice-water, neutralization with NaOH and separation of the precipitate by fdtration to afford amidines 345 in 66-86% yield (Equation 11). Some of the obtained amidines exhibit selective antibacterial activity <2003SC3969>. 

Acids react with a base to form a salt and water ( neutralization )... 

VIII. Acid + Base — Salt + Water (Neutralization)... 

Add 20g (0.08M) (VI) to 3 8% HBr in glacial acetic acid and stir and reflux for 6 hours. Pour onto ice and water, neutralize with solid sodium carbonate and extract with ether. Extract the ether with 10% aqueous NaOH, acidify the aqueous solution with HC1, extract with ether and dry, evaporate in vacuum (can distill) to get 2-(3,5-dihydroxyphenyl)-3-methyloctane (VII) (5-(l,2-dimethylheptyl)-res-orcinol). 

A. 0.02 M substituted benzaldehyde, 27 g acetic anhydride, 12 g fused K acetate in 250 ml round bottom flask with air condenser and CaCI2 tube. Heat on oil bath at 160° one hour and then at 175c for four hours. Pour into water (neutralize with Na carbonate and steam distill to recover unreacted aldehyde), cool, acidify and filter to get about 60% yield substituted cinnamic acid (I). 

Silica-based materials obtained by the sol-gel process are perhaps the most promising class of functional materials capable to meet such a grand objective. In the sol-gel process liquid precursors such as silicon alkoxides are mixed and transformed into silica via hydrolytic polycondensation at room temperature. Called soft chemitry or chimie douce, this approach to the synthesis of glasses at room temperature and pressure and in biocompatible conditions (water, neutral pH) has been pioneered by Livage and Rouxel in the 1970s, and further developed by Sanchez, Avnir, Brinker and Ozin. 

Landers et al. [97] and others [98] have described a wet digestion method for the determination of total sulphur in soils. In this method the sample (1.50-500mg) is placed in a digestion flask and heated in a sand bath to dryness at 250°C with 3ml of sodium hypobromite solution. The residue is resuspended with water, neutralized with formic acid, and then hydriodic acid reduction of the sample is followed to quantitatively recover the inorganic sulphate formed by wet oxidation. 

RP-HPLC has been employed for the determination of flavonoids and other phenolic compounds in cranberry juice. The neutral and acidic analytes were preconcentrated octadecyl silica SPE cartridges conditioned with distilled water (neutral analytes) or with 0.01 M HC1 (acidic compounds). Hydrolysis of samples was carried out in aqueous methanol solution acidified with 6 M HC1 at 35°C for 16h. Chromatographic separation was performed in an ODS column (150 X 4.6mm i.d. particle size 5/.an). Solvents A and B were water-acetic acid (97 3, v/v) and methanol, respectively. The gradient started with 0 per cent B (flow rate, 0.9 ml/min), reached 10 per cent B in lQmin (flowrate, 1.0 ml/min) and increased to 70 per cent B in 40min (flowrate, 1.0 ml/min). Analytes were detected at 280 and 360 nm. Some typical chromatograms are presented in Fig. 2.71. The concentrations of flavonoids and phenolic acids are compiled in Table 2.69. It was stated that the SPE-HPLC procedure makes possible the simultaneous determination of phenolic compounds and flavonoids, therefore, it can be employed for the measurement of these classes of analytes in other fruit juices [188],... 

PTA dissolved in water, neutralized with NaOH, and evaporated down until a precipitate was obtained. 

Only one polymorphic form of the substance has been observed. A study was undertaken to attempt to produce different forms by flash cooling and slow evaporation from various solvents (V, V-dimethylformamide, acetonitrile,ethanol, dichloromethane,2-propanol, water (neutral pH, pH 5, and pH 9), ethanol/watermixtures (1 1, neutral and at pH 5 and 9). No additional forms were observed upon examination of the resulting crystals by x-ray powder diffraction. 

Figure 3.3-6 The distribution ratios between [BMIMjlPFg] and water (neutral pH) for organic solutes correlate with literature partition functions of the solutes between octanol and water (log P).

The salts of the series are bright red crystalline bodies. They are soluble in water, neutral in reaction, and dilute mineral acids do not transform them into aquo-salts. The least soluble member of the series is the sulphate [(NH3)4Co (OH)2 Co(NH3)4](S04)a.2H30, which is prepared by heating hydroxo-aquo-tetrammino-cobaltic sulphate at 100° C. till it is constant in weight. The mass is extracted with water and the sparingly soluble sulphate collected and dried. The crude product so obtained is converted into the chloride and an aqueous solution of this then treated with a solution of sodium sulphate, when a crystalline precipitate of the diol-sulphate is obtained. It is collected, washed with water, alcohol, and finally with ether. It forms small red needle-shaped crystals which contain two molecules of water of hydration. 

The chloride may be prepared in similar manner to the nitrate from cobaltous chloride, and the other salts from the nitrate by double decomposition with soluble salts of the respective acids. All the salts of the series are soluble in water, neutral in reaction, and have a yellowish-brown colour. 

These pentammino-salts are mostly soluble in water, neutral in reaction, with the exception of the nitrite, which is alkaline. 

---