Potassium chloride, magnesium sulphate, water

W. C. Blasdale has applied these results to show what takes place during the fractional crystallization by the evaporation of soln. containing different proportions of the component salts—the separation of (i) sodium and potassium chlorides (ii) potassium chloride and sulphate (iii) potassium and sodium sulphate (iv) sodium sulphate and chloride and of (v) potassium salts from mixtures of sodium and potassium chlorides and sulphates. The results were then extended to samples of desert brine. J. H. Hildebrand also showed how J. H. van t Hoff s results show the course of the fractional crystallization of sea-water containing magnesium, sodium, and potassium sulphates and chlorides. 

Z14. System Water, magnesium chloride, magnesium sulphate, chloride of potassium, potassium sulphate. Investigations of Loewenherz, Van t Hoff, and Meyerhoffer.— An interesting example of these various considerations is found in the researches of Loewenherz, continued recently by Van t Hoff, Meyerhoffer, and Donnan. ... 

X i6. Four salts dissolved in water, one of them to saturation System Water, sodium chloride, potassium chloride, sodium sulphate, magnesium chloride.—Suppose that into the system water, potassium chloride, sodium sulphate, magnesium chloride, we introduce a new independent component, which we shall denote... 

Casein which is a phosphoprotein, is the chief nitrogenous constituent of milk, in which it occurs as a calcium salt in combination with calcium phosphate. Casein is insoluble in water, but its salts are readily soluble those of calcium, barium, strontium, and magnesium form opalescent colloidal solutions. The sodium, potassium, and ammonium salts form comparatively clear solutions, which pass through clay filters. Casein also forms salts with acids. It is precipitated from a solution of its salts and from milk by small quantities of mineral acids, and by larger amounts of acetic acid, but it dissolves in an excess of acid. Casein and its salts are precipitated from solutions by saturating the latter with sodium chloride, magnesium sulphate, or sodium sulphate. The solutions of the salts of casein... 

In a 500 ml. three-necked flask, equipped with a thermometer, a sealed Hershberg stirrer and a reflux condenser, place 32-5 g. of phosphoric oxide and add 115-5 g. (67-5 ml.) of 85 per cent, orthophosphoric acid (1). When the stirred mixture has cooled to room temperature, introduce 166 g. of potassium iodide and 22-5 g. of redistilled 1 4-butanediol (b.p. 228-230° or 133-135°/18 mm.). Heat the mixture with stirring at 100-120° for 4 hours. Cool the stirred mixture to room temperature and add 75 ml. of water and 125 ml. of ether. Separate the ethereal layer, decolourise it by shaking with 25 ml. of 10 per cent, sodium thiosulphate solution, wash with 100 ml. of cold, saturated sodium chloride solution, and dry with anhydrous magnesium sulphate. Remove the ether by flash distillation (Section 11,13 compare Fig. II, 13, 4) on a steam bath and distil the residue from a Claisen flask with fractionating side arm under diminished pressure. Collect the 1 4-diiodobutane at 110°/6 mm. the yield is 65 g. 

The distillate contains alcohol, toluene and water, and may be dried with anhydrous potassium carbonate and used again for esterification after the addition of the necessary quantity of alcohol alternatively, the toluene may be recovered by washing with water, drying with anhydrous calcium chloride or anhydrous magnesium sulphate, and distiUing. 

The experimental details for mono-M-propylanillne are as follows. Reflux a mixture of 230 g. of aniline and 123 g. of n-propyl bromide for 8-10 hours. Allow to cool, render the mixture alkafine, and add a solution of 150 g. of zinc chloride in 150 g. of water. Cool the mixture and stir after 12 hours, filter at the pump and drain well. Extract the thick paste several times with boiling light petroleum, b.p. 60-80° (it is best to use a Soxhlet apparatus), wash the combined extracts successively with water and dilute ammonia solution, and then dry over anhydrous potassium carbonate or anhydrous magnesium sulphate. Remove the solvent on a water bath, and distil the residue from a Claisen flask with fractionating side arm (well lagged). Collect the n-propyl-aniline at 218-220° the yield is 80 g. Treat the pasty solid zincichloride with an excess of. sodium hydroxide solution and steam distil 130 g. of pure aniline are recovered. 

In a 250 ml. distilling flask (1) place 122 g. (119 ml.) of p-phenylethyl alcohol and 40 g. of sodium hydroxide peUets (or 56 g. of potassium hydroxide). Heat is evolved. Warm gently until bubbles commence to form and the mixture separates into two sharply-defined layers. Distil slowly water, etc. passes over first accompamed by the gradual dis appearance of the upper phase. FinaUy the styrene passes over at 140 160° (mainly 150°) coUect this separately in a receiver containing about 0 1 g. of hydroquinone. Dry the distillate with a httle anhydrous calcium chloride or magnesium sulphate, and then distil under reduced pressure (2). C oUect the pure styrene at 42-43°/18 mm. The 3rield is 80 g. Add about 0-2 g. of hydroquinone (anti-oxidant) if it is desired to keep the phenylethylene. 

Esters. The most common impurities are the corresponding acid and hydroxy compound (i.e. alcohol or phenol), and water. A liquid ester from a carboxylic acid is washed with 2N sodium carbonate or sodium hydroxide to remove acid material, then shaken with calcium chloride to remove ethyl or methyl alcohols (if it is a methyl or ethyl ester). It is dried with potassium carbonate or magnesium sulphate, and distilled. Fractional distillation then removes residual traces of hydroxy compounds. This method does not apply to esters of inorganic acids (e.g. dimethyl sulphate) which are more readily hydrolysed in aqueous solution when heat is generated in the neutralisation of the excess acid. In such cases, several fractional distillations, preferably under vacuum, are usually sufficient. 

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