From sodium hydroxide solution

Phenarsazinic acid, or the chloride, is warmed with concentrated nitric acid (density I 4) and the temperature gradually raised to boiling-point. The dinitro-acid has also been obtained by the nitration of the oxide. It separates in bright yellow needles. The sodium salt forms glistening bronze plates from sodium hydroxide solution. This salt is dibasic, but replacement of the hydroxide by sodium carbonate gives a monobasic salt, crystallising in yellow needles. 

This patent utilizes the same principles that the Hess patent, U.S. 3,308,063, that we discussed previously, viz., the ability of an organic compound at high pressure and temperature to dissolve water. The objective of the Hess patent is the dissolution of water from sea water for subsequent recovery of salt-free water and the salt water is discarded. The objective of the this patent is the dissolution of water from sodium hydroxide solution for the purpose of concentrating the sodium hydroxide and the extracted water is discarded. 

The process for subsequent extraction of alkali earth elements from mineralized effluents rom the iodine-txomine production in Turkmenistan includes the investigation of the possibility of isolating calcium and strontium from sodium hydroxide solutions. 

Low background /F counting was also used to determine Tc in seawater. The nuclide was preconcentrated from seawater by adsorbing " TcOj on an anion exchanger. It was purified from other radionuclides by scavenging with iron(lll)-oxide hydrate and extracting from sodium hydroxide solution into methyl ethyl ketone. 

Either use a commercially available solution, in which case the concentration should be determined iodometrically, or prepare the solution from sodium hydroxide solution by introducing chlorine... 

Both assayed by extraction of about 0-3 g of the base from sodium hydroxide solution with chloroform which is washed and evaporated. The residue is dissolved in excess of 0-lN hydrochloric acid and back-titrated with O IN sodium hydroxide to methyl red indicator. 1 ml 0-lN — 0-02467 g of the hydrochloride and 0-02733 g of the nitrate. 

The assay for strychnine is the same as given under Injection of Strychnine after extracting the alkaloid with chloroform from sodium hydroxide solution. 

Dextromethorphan hydrobromide, CigH250N,HBr,H20, Mol. Wt. 370-3, is assayed in the B,P,C, by extracting about 0-3 g with chloroform from sodium hydroxide solution and titrating the extracts directly with 0-02N perchloric acid using methyl red as indicator, 1 ml 0-02N = 0-007047g of Ci8H250N,HBr. 

Assemble the apparatus shown in Fig. 56. F is a 200 ml. flat-bottomed flask supported on a sand-bath and connected by a glass delivery-tube to the wash-bottle B, which is about two-thirds full of 10% aqueous sodium hydroxide solution. A second delivery-tube leads from B into a beehive stand (or between two earthenware tiles placed side by side) in a pneumatic trough T containing water. 

IODOFORM FROM ACETONE. (Semi-micro Scale.) Required Acetone, 0 5 ml. 10% potassium iodide solution, 20 ml. 10% sodium hydroxide solution, 8 ml. zM sodium hypochlorite solution, 20 ml. 

Place 0 5 ml. of acetone, 20 ml. of 10% aqueous potassium iodide solution and 8 ml. of 10% aqueous sodium hydroxide solution in a 50 ml. conical flask, and then add 20 ml. of a freshly prepared molar solution of sodium hypochlorite. Well mix the contents of the flask, when the yellow iodoform will begin to separate almost immediately allow the mixture to stand at room temperature for 10 minutes, and then filter at the pump, wash with cold w ater, and drain thoroughly. Yield of Crude material, 1 4 g. Recrystallise the crude iodoform from methylated spirit. For this purpose, place the crude material in a 50 ml. round-bottomed flask fitted with a reflux water-condenser, add a small quantity of methylated spirit, and heat to boiling on a water-bath then add more methylated spirit cautiously down the condenser until all the iodoform has dissolved. Filter the hot solution through a fluted filter-paper directly into a small beaker or conical flask, and then cool in ice-water. The iodoform rapidly crystallises. Filter at the pump, drain thoroughly and dry. 

Naphthyl Acetate. CHgCOOCi H,. Dissolve 1 g. of pure 2-naphtnol in 5 ml. (r8 mols.) of 10% sodium hydroxide solution as before, add 10 g. of crushed ice, and i-i ml. (1-14 g., 1 5 mols.) of acetic anhydride. Shake the mixture vigorously for about 10-15 minutes the 2-naphthyl acetate separates as colourless crystals. Filter at the pump, wash with water, drain, and dry thoroughly. Yield of crude material, 1-4 g. (theoretical). Recrystallise from petroleum (b.p. 60-80 ), from which, on cooling and scratching, the 2-naphthyl acetate separates as colourless crystals, m.p, 71 yield, 10 g. 

Place I g. of benzamide and 15 ml. of 10% aqueous sodium hydroxide solution in a 100 ml. conical flask fitted with a reflux water-condenser, and boil the mixture gently for 30 minutes, during which period ammonia is freely evolved. Now cool the solution in ice-water, and add concentrated hydrochloric acid until the mixture is strongly acid. Benzoic acid immediately separates. Allow the mixture to stand in the ice-water for a few minutes, and then filter off the benzoic add at the pump, wash with cold water, and drain. Recrystallise from hot water. The benzoic acid is obtained as colourless crystals, m.p. 121°, almost insoluble in cold water yield, o 8 g. (almost theoretical). Confirm the identity of the benzoic acid by the tests given on p. 347. 

Hydrolysis of />-Tolunitrile. As in the case of benzonitrile, alkaline h> drolysis is preferable to hydrolysis by 70% sulphuric acid. Boil a mixture of 5 g. of p-tolunitrile, 75 ml. of 10% aqueous sodium hydroxide solution and 15 ml. of ethanol under a reflux water-condenser. The ethanol is added partly to increase the speed of the hydrolysis, but in particular to prevent the nitrile (which volatilises in the steam) from actually crystallising in the condenser. The solution becomes clear after about i hour s heating, but the boiling should be continued for a total period of 1-5 hours to ensure complete hydrolysis. Then precipitate and isolate the p-toluic acid, CH3CgH4COOH, in precisely the same way as the benzoic acid in the above hydrolysis of benzonitrile. Yield 5 5 g. (almost theoretical). The p-toluic acid has m.p. 178°, and may be recrystallised from a mixture of equal volumes of water and rectified spirit. 

Transfer the diazotised solution to a 600 mi. beaker, add 150 ml. of benzene, and stir the mixture vigorously to obtain an intimate mixture of the two liquids. Then again maintain the temperature at about 5° (by ice-salt cooling because of the heat evolved) whilst 27 ml. of 20% aqueous sodium hydroxide solution are added from a dropping-fiinnel during 40-50 minutes. When the addition of the alkali is complete, remove the ice-water bath, and allow the stirred mixture to reach room temperature. 

The recrystallisation of diazoaminobenzene has to be performed with care, as the substance is freely soluble in most liquids and tends moreover to decompose if its solution is not rapidly cooled. Place 2 g. of the crude, freshly prepared, well-drained material in a boiling-tube, add about 15-20 ml. of ethanol and 1-2 drops of 10% aqueous sodium hydroxide solution, and then heat rapidly until boiling if the solution should contain insoluble impurities, filter through a small fluted paper, and at once cool the filtrate in ice-water. The diazoaminobenzene should rapidly crystallise out from the cold and stirred solution filter the crystals rapidly at the pump whilst the solution is still cold, as... 

Add 10 g. of the crude hydrazobenzene to 80 ml. of ethanol contained in a flask fitted with a reflux water-condenser. Heat the mixture on a water-bath until the ethanol bolls, and then add 10 g. of zinc dust and 30 ml. of 30% aqueous sodium hydroxide solution. Remove the flask from the water-bath and shake the contents vigorously from time to time. After about 10 minutes, replace the flask on the water-bath and boil the contents for 3-5 minutes. Filter the mixture at the pump, transfer the filtrate to a beaker and cool in ice-water with stirring. The hydrazobenzene separates as colourless crystals, which are filtered off at the pump and drained. A portion when dried in a desiccator has m.p. 124°. 

Chill the concentrated solution of the amine hydrochloride in ice-water, and then cautiously with stirring add an excess of 20% aqueous sodium hydroxide solution to liberate the amine. Pour the mixture into a separating-funnel, and rinse out the flask or basin with ether into the funnel. Extract the mixture twice with ether (2 X25 ml.). Dry the united ether extracts over flake or powdered sodium hydroxide, preferably overnight. Distil the dry filtered extract from an apparatus similar to that used for the oxime when the ether has been removed, distil the amine slowly under water-pump pressure, using a capillary tube having a soda-lime guard - tube to ensure that only dry air free from carbon dioxide passes through the liquid. Collect the amine, b.p. 59-61°/12 mm. at atmospheric pressure it has b.p. 163-164°. Yield, 18 g. 

Dissolve I ml. of benzaldehyde and 0-4 ml. of pure acetone in 10 ml. of methylated spirit contained in a conical flask or widemouthed bottle of about 50 ml. capacity. Dilute 2 ml. of 10% aqueous sodium hydroxide solution with 8 ml. of water, and add this dilute alkali solution to the former solution. Shake the mixture vigorously in the securely corked flask for about 10 minutes (releasing the pressure from time to time if necessary) and then allow to stand for 30 minutes, with occasional shaking finally cool in ice-water for a few minutes. During the shaking, the dibenzal -acetone separates at first as a fine emulsion which then rapidly forms pale yellow crystals. Filter at the pump, wash well with water to eliminate traces of alkali, and then drain thoroughly. Recrystallise from hot methylated or rectified spirit. The dibenzal-acetone is obtained as pale yellow crystals, m.p. 112 yield, o 6 g. 

Meanwhile, filter the original cold reaction product at the pump, and wash the sulphonyl-methylaniline on the filter first with 10% sodium hydroxide solution (to ensure complete removal of the sulphonyl-aniline) and then with water drain thoroughly. Recrystallise from ethanol toluene-/)-sulphonyl-methylaniline, C H5N(CH3)S02C4H4CH3, is thus obtained as colourless crystals, m.p. 95° yield, 7-5 g. 

Nitrogen. To one portion of the filtrate, add z-3 ml. of 10, aqueous sodium hydroxide solution, then add about o-2 g. of ferrous sulphate and proceed as in the Lassaigiie nitrogen test (p, 322). Note, however, that the fiUal acidification with dilute siiphiiric acid must be made with care, owing to the vigorous evolution of carbon dioxide from the carbonate present. 

Transfer 25 ml. of this dilute solution by means of a pipette to a conical flask, and add similarly 50 ml. of Ml 10 iodine solution. Now-add 10% sodium hydroxide solution until the liquid becomes pale yeilow in colour, and allow the solution to stand, with occasional shaking, at room temperature for at least 10 minutes. Then acidify with dilute hydrochloric acid (free from chlorine) in order to liberate the remaining iodine. Titrate the latter w ith Mho sodium thiosulphate solution, using starch as an indicator in the usual way. 

Place about 50 ml. of 40% formalin solution in a conical flask and add at least 10 drops of phenolphthalein solution. No add ery carefully from a burette dilute sodium hydroxide solution (il/ 10 will serve the purpose) until the solution is just faintly pink. 

Dilute sodium hydroxide solution (and also sodium carbonate solution and sodium bicarbonate solution) can be employed for the removal of an organic acid from its solution in an organic solvent, or for the removal of acidic impurities present in a water-insoluble solid or liquid. The extraction is based upon the fact that the sodium salt of the acid is soluble in water or in dilute alkali, but is insoluble in the organic solvent. Similarly, a sparingly soluble phenol, e.g., p-naphthol, CioH,.OH, may be removed from its solution in an organic solvent by treatment with sodium hydroxide solution. 

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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