Sodium hydroxide addition

Other options for the purification of CA include dissolution in hot water, aqueous ammonia, aqueous formaldehyde, or hot dimethylformamide followed by filtration to remove most of the impurities. The CA is recoverable by cooling the aqueous solution (84), acidifying the ammonium hydroxide solution (85), or cooling the dimethylform amide solution with further precipitation of CA by addition of carbon tetrachloride (86). Sodium hydroxide addition precipitates monosodium cyanurate from the formaldehyde solution (87). 

A. M. Selikhanovich, G. A. Chuprina, and A. N. Olejnikov. Reagent for treating drilling muds—contains acrylic polymer, sodium hydroxide, additional diethylene glycol, and water. Patent RU 2087515-C, 1997. 

These basic materials eventually are converted to their neutral salts by use of some alkaline material, such as sodium hydroxide. Additional, minor ingredients are added, e.g, sodium silicate or magnesium sulfate, to control alkalinity, odor, and aging stability. 

Sodium Hydroxide. Addition of liquid chlorine to 20% sodium hydroxide solution resulted in a violent reaction.31... 

Procedure Fill the titrator buret with the 0.05 N Sodium Hydroxide solution, and following the manufacturer s instructions, set the temperature to 30° and the pH set point to 7.0. Transfer 15.0 mL of the Substrate Emulsion to the titration cell, and add a small stirrer bar. Add 1.0 mL of the diluted Sample Preparation, and actuate the titrator. Record the rate of 0.05 N Sodium Hydroxide addition. Stop the titration after a constant (linear) rate of addition has been observed for 5 min. Determine the addition rate, in milliliters per minute, from the linear portion of the recording and record this value as R. 

Typically, in cases where some minor impurity is isolated instead of the expected product, the whole stuff is washed into the waste and the experiment repeated with purified reactants and greater control over the reaction conditions. If Pedersen had followed this pattern of behavior (especially because product 214 was unable to complex the cation and therefore useless from the viewpoint of the initial practical request ), he probably would never again have had the chance to go to Stockholm to receive the Nobel Prize subsequently awarded to him (together with Donald Cram and Jean-Marie Lehn) in 1987. Fortunately, peculiarities displayed by 214 did not escape Pedersen s attention. In fact, while ether 214 was only slightly soluble in methanol, its solubility increased dramatically in the presence of sodium hydroxide. Additional tests showed that this effect was not base dependent and could be observed with many sodium salts, as well as with many other salts of inorganic cations. Even more intriguing was the observation that inorganic salts which were... 

As reaction (1) is strongly exothermic, the furfural is cooled to 2 °C before the sodium hydroxide solution is added, and the reactor content is stirred vigorously while this is done. Typically, a 28 % sodium hydroxide solution is used. The addition of the sodium hydroxide must be carried out slowly to make sure that the temperature does not exceed 20 C. In other words, the rate of sodium hydroxide addition depends on the efficiency of cooling. Customarily, this addition requires a period in the order of half an hour. 

Since the Cannizzaro reaction is slow, after completion of the sodium hydroxide addition the stirring must be continued for at least one hour. In the course of the reaction, con-... 

The first ring closure process investigated used a technique whereby 50% aqueous sodium hydroxide was added at a constant rate under conditions where the water was removed by azeotropic distillation with the excess epichlorohydrin and toluene solvent, giving a dehydrochlorination under essentially anhydrous conditions. Fig. 14 shows the conversion of chlorohydrin ester to glycidyl 2-ethylhexanoate using two different rates of addition of sodium hydroxide solution (0.25 mol. hr. i and 0.125 mol. hr. ). Excellent conversion to glycidyl 2-ethylhexanoate was obtained which may be seen to be relatively independent of the rate of sodium hydroxide addition. However in order to attain high yields (>99%) it may be seen that 40-50% excess (based on chlorohydrin ester) sodium hydroxide was required. 

For the high-resin-content formulation (Table 12), a partial addition of the PF resin can be made just after the initial mix and before sodium hydroxide addition if more fluidity is needed for propeller-type stirring. This formulation is more properly termed a blood-fortified exterior PF resin adhesive for hot-pressing plywood or laminated veneer lumber [52]. Even in quantities this small, the effect of the animal blood is to reduce the hot-press curing time by 2(%30% over that of phenolic resins used alone. For purposes of adhesive solid, calculation, the blood content can legitimately be included with the phenolic resin solids. 

Sodium hydroxide Addition of amines to carbon-carbon double bonds... 

Ideally samples should be analyzed in situ or at the site of sampling in the field. If direct measurements are not possible or are too expensive, samples should be analyzed as soon as possible to avoid the need for preservation. However, samples cannot always be analyzed directly and they may have to be stored for so long that preservation is necessary. The preservation of water samples is covered in ISO standard 5667/3 (1985). The preservation methods described in this standard include time limits for sample storage and analysis specifications for container material prevention of exposure to light temperature control (2-5°C) pH control (addition of sulfuric, nitric, or phosphoric acid, or sodium hydroxide) addition of special reagents (e.g., ethylenediaminetetraacetic acid (EDTA), copper sulfate, zinc acetate, formaldehyde) to retard biological activity, hydrolysis of compounds and complexes and measures for reducing volatility of compounds and sorption effects. 

Figure 14. Example of the result of sodium hydroxide additions to the process on surfaetant coneentrations and, in turn, the electric charges on different surfaees.

Introduce into a 4 cm beaker, 3 cm of distilled water, 2 g sodinm hydroxide and fresh boiling chips, heat to incipient boiling and add 675 g of AnalaR potassium sulfate. Adjust to pH 10 or higher by sodium hydroxide addition. Boil for 20 minutes to expel ammonia. Filter the boiling solution on a Buchner funnel throngh (previously hot water washed) Whatman No. 42 filter paper. Cool the filtrate to 5 °C and vacuum filter off the small uniform crystals. Dry the crystals in an air oven (yield 450 g). Allow to cool in a desiccator and store in well stoppered glass bottle. 

Note 7. Volatile acids in digestion mixture. It has been found that traces of steam volatile acids remain in the acid digestion mixture after digestion of certain organic materials. These are removed by passing steam through the diluted digestion mixture prior to sodium hydroxide addition. This acidic distillate is rejected. 

Two examples of unsupported proline-based catalysts are compounds 88 and 89 (Figure 24.30). Dipeptide 88 was used in water in the presence of NaOH in the addition of ketones to nitroalkenes. The presence of sodium hydroxide additive was crucial for the success of the reaction [109]. Catalyst 89 was designed on the structurally rigid hexahydropyrrolo[2,3]indole skeleton and efficiently catalyzed the enantioselective addition of aldehydes to nitroalkenes both in methanol and water [110]. The same catalyst was also used in the addition of aldehydes to vinyl sulfone followed by reduction with sodium borohydride. In this case water was a better reaction medium than methanol [111]. 

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