Sodium acetate hydroxide

Since hydroxylamine is usually available only in the form of its salts, e.g., the hydrochloride or sulphate, the aqueous solution of these salts is treated with sodium acetate or hydroxide to liberate the base before treatment with the aldehyde or ketone. Most oximes are weakly amphoteric in character, and may dissolve in aqueous sodium hydroxide as the sodium salt, from which they can be liberated by the addition of a weak acid, e.g., acetic acid. 

Dissolve 36 g. of sodium hydroxide in 160 ml. of water contained in a 500 ml. conical flask, and chill the stirred solution to 0-5° in ice-water. Now add io-8 ml. (32-4 g.) of bromine slowly to the stirred solution exercise care in manipulating liquid bromine ) during this addition the temperature rises slightly, and it should again be reduced to 0-5°. Add a solution of 12 g. of acetamide in 20 ml. of water, in small portions, to the stirred hypobromite solution so that the temperature of the mixture does not exceed 20° the sodium acet-bromoamide is thus obtained in the alkaline solution. Now remove the flask from the ice-water, and set it aside at room temperature for 30 minutes. 

Unsymmetrical diaryls may be prepared by treating an aryl diazonium salt solution with sodium hydroxide or sodium acetate in the presence of a liquid aromatic compound. Thus 2-chlorodiphenyl is readily formed from o-chloro phenyl diazonium chloride and sodium hydroxide solution (or sodium acetate solution) in the presence of benzene ... 

The following are examples of the above procedure. A mixture of diethylamine and re-butyl alcohol may be separated by adding sufficient dilute sulphuric acid to neutralise the base steam distillation will remove the alcohol. The amine can be recovered by adding sodium hydroxide to the residue and repeating the distillation. A mixture of diethyl ketone and acetic acid may be treated with sufficient dilute sodium hydroxide solution to transform the acid into sodium acetate and distilling the aqueous mixture. The ketone will pass over in the steam and the non-volatile, stable salt will remain in the flask. Acidification with dilute sulphuric acid hberates acetic acid, which can be isolated by steam distillation or by extraction. 

The production of triphenyl tin hydroxide [76-87-9] and triphenyl tin acetate [900-95-8] start with triphenyl tin chloride, which is prepared by the Kocheshkov redistribution reaction from tetraphenyltin and tin tetrachloride. The hydroxide is prepared from the chloride by hydrolysis with aqueous sodium hydroxide. The acetate can be made directiy from the chloride using sodium acetate or from the hydroxide by neutrali2ation with a stoichiometric quantity of acetic acid. 

It is essential to neutralize any strong acid present before distilling lactic esters otherwise, condensation by ester interchange occurs, with liberation of alcohol and production of polylactic acid, a linear polyester. Other neutralizing agents, such as alkali or alkaline-earth hydroxides or carbonates, doubtless could be used satisfactorily instead of sodium acetate. 

A mixture of 10 g of the glyoxylic acid, 100 ml of acetic anhydride, and 0.5 g of 2,4-dinitrobenzenesulfonic acid is stirred at 25° for 2 hr. Sodium acetate (0.5 g) is added and the mixture concentrated in vacuum at 50°. The residue is taken up in 100 ml of benzene and washed with two portions of 2.5 N sodium hydroxide to remove the remaining acetic anhydride. The benzene solution is washed with water, dried and concentrated in vacuum to dryness. Crystallization from 40 ml of absolute ethanol gives 9.8 g (85%) of 3a,20,23-trihydroxy-16a-methyl-11 -oxo-21 -norchola-17(20),22-dienoic acid-24(20)-lactone 3,23-diacetate mp 165-175°. 

When the arenediazonium compound 1 is treated with sodium acetate, instead of alkali hydroxide, the reaction proceeds via an intermediate nitroso compound, and is called the Hey reaction. 

A number of halogen acceptors, such as alkali and alkaline hydroxides, aceutes, ethoxides, amines, and ammonia, have been used successfully. The pyrida2ine 9 was prepared via dehydrohalogenation of 8 using sodium acetate as acceptor (37). 

A mixture of 14 g (0.05 mol) of a A-diphenyl-7-dlmethylaminovaleronitrile, 16 g (0.2 mol) of sodium acetate, 14 g (0.2 mol) of hydroxylamine hydrochloride and 75 ml of ethyl alcohol was refluxed IB hours. The mixture was cooled, poured Into water and neutralized with ammonium hydroxide. The heavy white precipitate solidified on standing. The material was filtered and recrystallized from isopropanol. After three recrystallizations the aminopentamide product melted at 177° to 179°C. 

The food industry uses the acetic acid/sodium acetate buffer to control the pH of food. Given the following mixtures of acetic acid, HC2H302 (HAc), and sodium hydroxide, show by calculation which of the following solutions is a buffer. 

Discussion. Arsenates in solution are precipitated as silver arsenate, Ag3 As04, by the addition of neutral silver nitrate solution the solution must be neutral, or if slightly acid, an excess of sodium acetate must be present to reduce the acidity if strongly acid, most of the acid should be neutralised by aqueous sodium hydroxide. The silver arsenate is dissolved in dilute nitric acid, and the silver titrated with standard thiocyanate solution. The silver arsenate has nearly six times the weight of the arsenic, hence quite small amounts of arsenic may be determined by this procedure. 

Weak acid with a strong base. In the titration of a weak acid with a strong base, the shape of the curve will depend upon the concentration and the dissociation constant Ka of the acid. Thus in the neutralisation of acetic acid (Ka— 1.8 x 10-5) with sodium hydroxide solution, the salt (sodium acetate) which is formed during the first part of the titration tends to repress the ionisation of the acetic acid still present so that its conductance decreases. The rising salt concentration will, however, tend to produce an increase in conductance. In consequence of these opposing influences the titration curves may have minima, the position of which will depend upon the concentration and upon the strength of the weak acid. As the titration proceeds, a somewhat indefinite break will occur at the end point, and the graph will become linear after all the acid has been neutralised. Some curves for acetic acid-sodium hydroxide titrations are shown in Fig. 13.2(h) clearly it is not possible to fix an accurate end point. 

C04-0024. Determine whether the following salts are soluble or insoluble (a) sodium acetate (b) AgN03 (c) barium hydroxide (d) CaO (e) lead(II) sulfate (f) ZnCl2 and (g) manganese(II) sulfide. 

Mobile phase The HPLC mobile phase is made up as follows. Prepare 2 L of acetate buffer by dissolving 13.6 g of sodium acetate and 6 mL of glacial acetic acid in 2 L of deionized water. Adjust the solution to pH 4.8 with concentrated sodium hydroxide solution (or glacial acetic acid) if necessary. Mix 2 L of buffer with 1.6-2 L (the amount depends on the particular commodity) of methanol. Eilter the solution through a 0.22-pm Nylon 66 filter membrane before using the mobile phase Absolute ethanol Aaper Alcohol and Chemical Co. (200 proof)... 

How can you make a polyester and a polyamide Objectives Prepare a polyester from phthalic anhydride and ethylene glycol. Prepare a polyamide from adipoyl chloride and hexamethylenediamine. phthalic anhydride (2.0 g) sodium acetate (0.1 g) ethylene glycol (1 mL) 5% adipoyl chloride in cyclohexane (25 mL) 50% aqueous ethanol (10 mL) 5% aqueous solution of hexamethylenediamine (25 mL) 20% sodium hydroxide (NaOH) (1 mL) scissors copper wire test tube test-tube rack 10-mL graduated cylinder 50-mL graduated cylinder 150-mL beakers (2) ring stand clamp Bunsen burner striker or matches balance weighing papers (2)... 

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