Sodium hydroxide chloride

Anhydrous hydrosulphites are obtained as products of methods described on p. 225. Commercially the anhydrous sodium salt is manufactured in large quantities on account of its greater stability than the hydrated Na2S204.2Ha0. The latter can be dehydrated by extraction with warm alcohol or acetone at 60° to 70° C. It is also possible to produce the anhydrous salt directly by precipitation of the aqueous solution with alcohol at 60° to 70° C., or even by salting-out the solution at this temperature by the addition of sodium hydroxide, chloride, sulphate, carbonate, nitrate or acetate with sodium hydroxide solution of 50 per cent, concentration the anhydrous salt can be separated even at 20° C.1... 

Diethylamine, CH3CH2)2NH. B.p. 55-5°C. Forms a crystalline i hydrate. Prepared by the action of a boiling solution of sodium hydroxide on nitrosodielhylaniline. Forms crystalline compounds with many metallic chlorides. 

Trichloroethylene is not attacked by dilute acids or alkalis, but when heated with sodium hydroxide under pressure it yields sodium gly-collate. In the presence of light and oxygen dichloroethanoyl chloride is formed, which can react with any moisture present to give small amounts of highly corrosive HCl. Numerous stabilizers have been patented. 

It is quite clear, first of all, that since emulsions present a large interfacial area, any reduction in interfacial tension must reduce the driving force toward coalescence and should promote stability. We have here, then, a simple thermodynamic basis for the role of emulsifying agents. Harkins [17] mentions, as an example, the case of the system paraffin oil-water. With pure liquids, the inter-facial tension was 41 dyn/cm, and this was reduced to 31 dyn/cm on making the aqueous phase 0.00 IM in oleic acid, under which conditions a reasonably stable emulsion could be formed. On neutralization by 0.001 M sodium hydroxide, the interfacial tension fell to 7.2 dyn/cm, and if also made O.OOIM in sodium chloride, it became less than 0.01 dyn/cm. With olive oil in place of the paraffin oil, the final interfacial tension was 0.002 dyn/cm. These last systems emulsified spontaneously—that is, on combining the oil and water phases, no agitation was needed for emulsification to occur. 

Sodium hydroxide is manufactured by electrolysis of concentrated aqueous sodium chloride the other product of the electrolysis, chlorine, is equally important and hence separation of anode and cathode products is necessary. This is achieved either by a diaphragm (for example in the Hooker electrolytic cell) or by using a mercury cathode which takes up the sodium formed at the cathode as an amalgam (the Kellner-Solvay ceW). The amalgam, after removal from the electrolyte cell, is treated with water to give sodium hydroxide and mercury. The mercury cell is more costly to operate but gives a purer product. 

By the electrolysis of concentrated sodium chloride solution this process was initially used primarily for the production of sodium hydroxide but the demand for chlorine is now so great that the chlorine is a primary and not a by-product. 

A compound of cobalt has the formula Co(NH3)jtCl. 0.500 g of it was dissolved in 50.00 cm M hydrochloric acid the excess acid required 40.00 cm M sodium hydroxide solution to neutralise it. Another 0.500 g portion of the compound was dissolved in water and allowed to react with excess silver nitrate solution. 0.575 g of silver chloride was precipitated. 

If a compound has been recrystallised from petrol, benzene, etc.y some freshly cut shavings of clean paraffin wax should be added to the calcium chloride in (A) or to the sodium hydroxide in D, The surface of the wax absorbs organic solvent vapours (particularly the hydrocarbons) and the last trace of such solvents is thus readily removed from the recrystallised material. 

Both forms sublime very readily, even at room temperature a small sample on exposure to the air will completely volatilise in a short time, particularly on a warm day or if the sample is exposed to a gentle current of air. Hence the above method for rapid drying. A sample confined in an atmospheric desiccator over calcium chloride rapidly disappears as the vapour is adsorbed by the calcium chloride. A sample of the hexahydrate similarly confined over sodium hydroxide undergoes steady dehydration with initial liquefaction, for the m.p. of the hydrated-anhydrous mixture is below room temperature as the dehydration proceeds to completion, complete resolidification occurs. 

Aluminium isopropoxide can be obtained as a fine powder from technical sources. When the bottle has once been opened however, the stopper should be firmly replaced and covered with wax more conveniently, the stoppered bottle can be kept in an atmospheric desiccator over calcium chloride or sodium hydroxide, preferably in the dark. 

Place the distillate in a separating-funnel and extract the benzonitrile twice, using about 30 ml. of ether for each extraction. Return the united ethereal extracts to the funnel and shake with 10% sodium hydroxide solution to eliminate traces of phenol formed by decomposition of the benzenediazonium chloride. Then run off the lower aqueous layer, and shake the ethereal solution with about an equal volume of dilute sulphuric acid to remove traces of foul-smelling phenyl isocyanide (CaHjNC) which are always present. Finally separate the sulphuric acid as completely as possible, and shake the ether with water to ensure absence of acid. Run off the water and dry the benzonitrile solution over granular calcium chloride for about 20 minutes. 

When an aqueous solution of a diazonium salt is added to an alkaline solution of a phenol, coupling occurs with formation of an azo-compound (p. 188). If ho vc cr the ntiueous solution of the diazonium salt, t. . ., />-bromohenzene diazonium chloride, is mixed with an excess of an aromatic hydrocarbon, and aqueous sodium hydroxide then added to the vigorously stirred mixture, the diazotate which is formed, e.g., BrC,H N OH, dissolves in the hydrocarbon and there undergoes decomposition with the formation of nitrogen and two free radicals. The aryl free radical then reacts with the hydrocarbon to give a... 

In the Schotten-Baumann method of benzoylation, the hydroxyl- or amino-compound (or a salt of the latter) is dissolved or suspended in an excess of 10% aqueous sodium hydroxide solution, a small excess (about 10% more than the theoretical amount) of benzoyl chloride is then added and the mixture vigorously shaken. Benzoylation proceeds smoothly under these conditions, and the solid benzoyl compound, being insoluble in water, separates out. The sodium hydroxide then hydrolyses the excess of benzoyl chloride, giving sodium... 

Add I ml. (1 04 g.) of aniline to 15 ml. of 10% aqueous sodium hydroxide solution contained in a wide-necked bottle as before, and then add 1-5 ml. (1-7 g.) of benzoyl chloride, and shake vigorously for 15-20 minutes. The mixture becomes warm, and the crude benzoyl derivative separates as a white... 

Place I ml. of benzyl alcohol in a boiling-tube and add 6 ml. of 10% sodium hydroxide solution add also 6 ml. of water to moderate the subsequent reaction, otherwise the rise in temperature may cause hydrolysis of some of the ester produced. Now add r-q g. of finely powdered />-nitrobenzoyl chloride, and shake the well-corked tube vigorously. The mixture becomes warm, and the solid ester rapidly... 

The reaction between 3,5 dinitrobenzoyl chloride and compounds containing the OH, NHj, or NH groups is very rapid, and therefore is particularly suitable for identification purposes cf. pp. 335, 338, 381). It is usual to have sodium hydroxide present during the reaction with phenols and amino-acids, but this is not necessary with alcohols if they are dry. 

The Schotten-Baumann reaction may also be carried out, using, for example, benzene sulphonyl chloride, CeH,SO,Cl (. e., the acid chloride of benzene sulphonic acid, C H5SOjOH) in place of benzoyl chloride, and similar deri a-tives are obtained. Thus when phenol is dissolved in an excess of 10% sodium hydroxide solution, and then shaken with a small excess of benzene sulphonyl... 

Required Phenol, 0-4 g. 10% sodium hydroxide, 2-5 ml. toluene-/)-sulphonyl chloride, 0-9 g. acetone, 4 ml. 

Arsonic acids, like carboxylic and sulphonic acids (pp. 349, 353), usually give crystalline benzylthiouronium salts. Add just sufficient dilute aqueous sodium hydroxide dropwise with shaking to a suspension of 0 5 g. of phenylarsonic acid in 10 ml. of water to give a clear solution. Then add 0 5 g. of benzylthiouronium chloride dissolved in 10 ml. of water. Filter off the precipitated benzylthiouronium salt, wash with water and dry m.p. 114-117° it tends to dissociate on attempted recrystallisation. 

In the example given below, phenylarsonic acid is reduced to dichlorophenyh arsine, Ccll jAsCl. This compound when added to aqueous sodium hydroxide and treated with benzyl chloride gives benzylphenylarsinic acid, which is readily isolated from solution. 

Add about 0 2 g. of ferrous sulphate crystals to the first portion of the filtrate contained in a boiling-tube. An immediate dark greenish-grey precipitate of ferrous hydroxide should occur if the mixture remains clear, add a few ml. of sodium hydroxide solution. Now boil the mixture gently for a few minutes to ensure formation of the ferrocyanide, cool under the tap, add one drop of ferric chloride solution, and then acidify... 

Z>) Toluene-p-sulphonylotion (p. 247). Proceed as in 3(a), but using 1 5 g of toluene-p-sulphonyl chloride, either finely pow dered or in concentrated acetone solution. Note. The sulphonyl derivative of a primary amine is soluble in aqueous sodium hydroxide, and the final solution must be diluted and acidified to precipitate the product. Recrystallise and take the m.p. (M.ps., pp. 550-551.)... 

B) Benzoyl derivatives. Most amino-acids can be benzoyl-ated when their solutions in 10% aqueous sodium hydroxide are shaken with a small excess of benzoyl chloride until a clear solution is obtained (Schotten-Baumann reaction, p. 243). Acidification of the solution then precipitates the benzoyl derivative and the excess of benzoic acid, and the mixture must be filtered off, washed with water, and recrystallised (usually from ethanol) to obtain the pure derivative. (M.ps., p. 555 )... 

A) Benzoyl Derivative. Since acetylation and benzoylation do not always proceed smoothly with nitrophenols, it is best to reduce them to the aminophenol as in (3) above. Add an excess of 20% aqueous sodium hydroxide to the reaction mixture after reduction, cool and then add a small excess of benzoyl chloride, and shake in the usual way. The dibenzoyl derivative wiU separate. Filter, wash with water and recrystalUse. (M.ps., p. 551.)... 

The dibenzoyl derivatives can be prepared by the normal Schotten-Baumann method, using 10% aqueous sodium hydroxide and an excess of benzoyl chloride, but the m.ps. of the dibenzoyl derivatives are inconveniently high (p- ssO-... 

II This dual tilling permits the absorption of both acid smd basic vapours which may be evolved. Thus an amine hydrochloride, which has been recrystallised from concentrated hydrochloric acid, may be readily dried in such a desiccator. If concentrated sulphuric acid alone were used, so much hydrogen chloride would be liberated that tlie pressure inside the desiccator would rise considerably, smd the rate of drying would be reduced. With sodium hydroxide present, however, the hydrogen chloride is removed, smd tho water is absorbed in the normal manner by the reagents but largely by the acid. 

By treatment with anhydrous aluminium chloride (Holmes and Beeman, 1934). Ordinary commercial, water-white benzene contains about 0 05 per cent, of thiophene. It is first dried with anhydrous calcium chloride. One litre of the dry crude benzene is shaken vigorously (preferably in a mechanical shaking machine) with 12 g. of anhydrous aluminium chloride for half an hour the temperature should preferably be 25-35°. The benzene is then decanted from the red liquid formed, washed with 10 per cent, sodium hydroxide solution (to remove soluble sulphur compounds), then with water, and finally dried over anhydrous calcium chloride. It is then distilled and the fraction, b.p. 79-5-80-5°, is collected. The latter is again vigorously shaken with 24 g. of anhydrous aluminium chloride for 30 minutes, decanted from the red liquid, washed with 10 per cent, sodium hydroxide solution, water, dried, and distilled. The resulting benzene is free from thiophene. 

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