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Sodium sulphate and water

Since, as has already been stated, each solid substance has its own solubility curve, there are three separate curves to be considered in the case of sodium sulphate and water. Where two curves cut, the solution must be saturated with respect to two solid phases at the point B, therefore, the point of intersection of the solubility curve of anhydrous sodium sulphate with that of the decahydrate, the solution must be saturated with respect to these two solid substances. But a system of two components existing in four phases, anhydrous salt—hydrated salt —solution— vapour, is invariant and this invariability will remain even if only three phases are present, provided that one of the factors, pressure, temperature, or concentration of components retains a constant value. This is the case when solubilities are determined in open vessels the pressure is then equal to atmospheric pressure. Under these circumstances, then, the system, anhydrous sodium sulphate — decahydrate—solution, will possess no degree of freedom, and can exist, therefore, only at one definite temperature and when the solution has a certain definite composition. The temperature of this point is 32 383°, or, in round figures, 32 4°, and the solution contains 33 20 per cent, of anhydrous salt. [Pg.176]

Further, the behaviour of sodium sulphate and water furnishes a very good example of the fact that a break in the solubility curve occurs when, and only when, the solid phase undergoes change. So long as the decahydrate, for example, remains unaltered in contact with the solution, the solubility curve is continuous but when the anhydrous salt appears in the solid phase, a distinct change in the direction of the solubility curve is observed. [Pg.178]

The vapour pressure of the different systems of sodium sulphate and water can best be studied with the help of the diagram in Fig. 75, The curve ABCD represents the vapour-pressure curve of the saturated solution of anhydrous sodium sulphate. GC is the pressure cuiwe of decahydrate -f- anhydrous salt, which, as we have seen, cuts the curve ABCD at the quadruple point, 32 6°. Since at this point the solution is saturated with respect to both the anhydrous salt and the deca-... [Pg.179]

B. Sulphur Dioxide and Water.—In the case just studied we have seen that the components can combine to form definite compounds possessing stable melting-points. The curves of equilibrium, therefore, resemble in their general aspect those of calcium chloride and water, or of ferric chloride and water. In the case of sulphur dioxide and water, however, the melting-point of the compound formed cannot be realised, because transition to another system occurs retroflex concentration-temperature curves are therefore not found here, but the curves exhibit breaks or sudden changes in direction at the transition points, as in the case of the systems formed by sodium sulphate and water. The case of sulphur dioxide and water is also of interest from the fact that two liquid phases can be formed. [Pg.200]

Ctystallizing system sodium carbonate, sodium sulphate, and water. The regions above the solubility isotherms demark undersaturated solution. Aity eompositions below the solubility isotherms are supersaturated and not stable. They deeompose to either one of the two or both crystalline solids (precipitate) and to the depleted solution (mother liquor). [Pg.67]

A fresh sample of dimethyl sulphate should be employed an old sample, or one that has been frequently exposed to the air, should be shaken with water, separated, dried over sodium sulphate, and distilled (b.p. 188"). [Pg.222]

Bromoform. Commercial bromoform should be shaken thoroughly with water, separated, dried over powdered anhydrous sodium sulphate and then fractionally distilled under reduced pressure using a water-condenser. It should be stored in a dark cupboard. It is an excellent solvent, has the advantage of a high Constant, and very seldom causes association of the solute. [Pg.435]

Vinylacetic acid. Place 134 g. (161 ml.) of allyl cyanide (3) and 200 ml. of concentrated hydrochloric acid in a 1-htre round-bottomed flask attached to a reflux condenser. Warm the mixture cautiously with a small flame and shake from time to time. After 7-10 minutes, a vigorous reaction sets in and the mixture refluxes remove the flame and cool the flask, if necessary, in cold water. Ammonium chloride crystallises out. When the reaction subsides, reflux the mixture for 15 minutes. Then add 200 ml. of water, cool and separate the upper layer of acid. Extract the aqueous layer with three 100 ml. portions of ether. Combine the acid and the ether extracts, and remove the ether under atmospheric pressure in a 250 ml. Claisen flask with fractionating side arm (compare Fig. II, 13, 4) continue the heating on a water bath until the temperature of the vapour reaches 70°. Allow the apparatus to cool and distil under diminished pressure (compare Fig. II, 20, 1) , collect the fraction (a) distilling up to 71°/14 mm. and (6) at 72-74°/14 mm. (chiefly at 72 5°/ 14 mm.). A dark residue (about 10 ml.) and some white sohd ( crotonio acid) remains in the flask. Fraction (6) weighs 100 g. and is analytically pure vinylacetic acid. Fraction (a) weighs about 50 g. and separates into two layers remove the water layer, dry with anhydrous sodium sulphate and distil from a 50 ml. Claisen flask with fractionating side arm a further 15 g. of reasonably pure acid, b.p. 69-70°/12 mm., is obtained. [Pg.465]

In a 250 ml. conical flask mix a solution of 14 g. of sodium hydroxide in 40 ml. of water and 21 g. (20 ml.) of pure benzaldehyde (Section IV,115). Add 15 g. of hydroxylamine hydrochloride in small portions, and shake the mixture continually (mechanical stirring may be employed with advantage). Some heat is developed and the benzaldehyde eventually disappears. Upon coohiig, a crystalline mass of the sodium derivative separates out. Add sufficient water to form a clear solution, and pass carbon dioxide into the solution until saturated. A colourless emulsion of the a or syn-aldoxime separates. Extract the oxime with ether, dry the extract over anhydrous magnesium or sodium sulphate, and remove the ether on a water bath. Distil the residue under diminished pressure (Fig. 11,20, 1). Collect the pure syn-benzaldoxime (a-benzald-oxime) at 122-124°/12 mm. this gradually solidifies on cooling in ice and melts at 35°. The yield is 12 g. [Pg.719]

Benzil monohydrazone. Method 1. Boil a mixture of 26 g. of hydrazine sulphate, 55 g. of crystallised sodium acetate and 125 ml. of water for 5 minutes, cool to about 50°, and add 115 ml. of methyl alcohol. Filter off the precipitated sodium sulphate and wash with a little alcohol. Dissolve 25 g. of benzil (Section IV,126) in 40 ml. of hot methyl alcohol and add the above hydrazine solution, heated to 60°. Most of the benzil hydrazone separates immediately, but reflux for 30 minutes in order to increase the yield. Allow to cool, filter the hydrazone and wash it with a httle ether to remove the yellow colour. The yield is 25 g., m.p. 149-151° (decomp.). [Pg.856]

To 10 c.c. of the oil (otto of rose or rose-geranium oil) 10 c.c. of formic acid 100 per cent, (specific gravity 1 22) is added, and the mixture gently boiled under a reflux condenser for one hour. The mixture is cooled, 100 c.c. of water added, and the whole transferred to a separator. The aqueous layer is rejected, and the oil washed with successive quantities of water as in the acetylation process. The formylated oil is dried with anhydrous sodium sulphate, and about 2 grams neutralised and saponified with alcoholic potash in the usual manner. The percentage of citronellol is then calculated from the following formula —... [Pg.334]

Ten grams of hydroxylamine hydrochloride are dissolved in 25 c.c. of water 10 grams of carbonate of potash, separately dissolved in 25 c.c. of water, are then added and the mixture filtered. With this solution 10 grams of the oil are thoroughly shaken for two hours at 15° to 18° C. The oil is then separated, dried with anhydrous sodium sulphate, and acetyl-ated with twice its volume of acetic. anhydride and one-fifth of its weight of anhydrous sodium acetate for two hours under a reflux condenser. The oil is washed, dried, and neutralised, and a weighed quantity (about 2 grams) saponified with alcoholic potash in the usual manner. [Pg.335]

Packaging materials Materials to be used in contact with metals should be as free as possible from corrosive salts or acid. BS 1133, Section 7 1967 gives limits for non-corrosive papers as follows chloride, 0-05% (as sodium chloride) sulphate, 0-25% (as sodium sulphate) and pH of water extract 5 -5-8 0. Where there is doubt, contact corrosion tests may be necessary in conditions simulating those in the package. [Pg.772]

H-l,3-ditellurole. Under an atmosphere of argon, 0.23 g (2.4 mmol) of trimethylsily-lacetylene are dissolved in 5 mL dry tetrahydrofuran. The solution is cooled to -70°C. n-Butyl lithium (1.0 mL, 2.4 M, 24 mmol) is dropped into the stirred solution. Then 0.20 g (2.0 mmol) of tellurium powder is added. The mixture is warmed to 20°C and kept at this temperature for 2 h. To this mixture, cooled again to -70°C, is added a solution of 0.35 g (2.0 mmol) of chloroiodomethane in 1 mL of tetrahydrofuran. The mixture is stirred for 15 min and then quenched with 50 mL water. The product is extracted with three 15 mL portions of dichloromethane. The combined extracts are washed with brine, dried with anhydrous sodium sulphate and filtered. The filtrate is concentrated to give trimethylsilylethynyl chloromethyl tellurium as a pale-yellow oil. Tellurium powder (0.125 g, 1.0 mmol) is added to 2 mL of a 1 M solution (2.0 mmol) of lithium triethylborohydride in ethanol. The mixture is stirred at 20°C for 2 h under an atmosphere of argon. Then 2 mL of 1 M sodinm ethoxide in ethanol are added followed by 0.27 g (1.0 mmol) of trimethylsilylethynyl chloromethyl tellurium dissolved in 2 mL dimethylformamide. The mixture is stirred for 15 h at 20°C, then diluted with 25 mL water and extracted with three 15 mL portions of dichloromethane. The combined extracts are dried with anhydrons sodinm snlphate, fdtered and the filtrate concentrated. The residue is chromatographed on silica gel with hexane/dichloromethane (1 1) as mobile phase. The fractions containing the prodnct are concentrated and recrystallized from methanol 65% yield, m.p. 85°C. [Pg.306]

General procedure for the cyclization of f-(aryltelluro)propenoyl chlorides with aluminium chloride The propenoyl chloride derivatives were dissolved in methylene chloride (1 g, 10 mL) under a nitrogen atmosphere. The solution was cooled to -78°C, and 1.1 equiv of aluminium chloride was added. The cooling bath was removed and the reaction was allowed to warm to room temperature. After stirring for 1 h at room temperature, the reaction mixture was poured into ice-water, and the products were extracted with several portions of methylene chloride. The combined methylene chloride extracts were dried over sodium sulphate and concentrated. The residues were recrystallized from methanol if NMR spectroscopy showed a single product. [Pg.312]

Take the total amount of succinaldehyde (obtained from 4 of the above syntheses combined) and without further treatment or purification (this had better be 15.5 g of succindialdehyde) put into an Erlenmeyer flask of 4-5 liters capacity. Add 21.6 g of methylamine hydrochloride, 46.7 g of acetonedicarboxylic acid, and enough water to make a total volume of 2 liters. Adjust the pH to 8-10 by slowly adding a saturated solution of disodium phosphate. The condensate of this reaction (allow to set for about 6 days) is extracted with ether, the ethereal solution is dried over sodium sulphate and distilled, the product coming over at 113° at 25 mm of pressure is collected. Upon cooling, 14 g of tropinone crystallizes in the pure state. Tropinone can also be obtained by oxidation of tropine with potassium dichromate, hut I could not find the specifics for this operation. [Pg.67]

Diethyl phenyl ethyl malonate. 1 mole of benzyl cyanide is added dropwise to a solution of 1 mole of ethyl carbonate in 2 liters of anhydrous ethanol containing 5 g of clean sodium metal. This mixture is refluxed (preferably on a steam bath) for 5 hours. It is then cooled and to it is added a cooled mixture of 40 g of sulfuric acid in 100 ml of anhydrous ethanol. This alcoholic solution is refluxed for 5 hours, cooled, neutralized with sodium ethylate (use external indicator). The mixture is evaporated to half bulk, filtered from the sodium sulphate and to it is added 1 mole of clean metallic sodium. Reflux while adding 1 mole of ethyl bromide dropwise. Heat for another 2 hours after the addition is completed. Remove the alcohol by distillation and dissolve the remaining residue in water. Extract the substance from the water with benzene and after drying, the benzene is recovered and the ester should be purified by distilling in vacuo. [Pg.100]

Geometric effects coupled with diffusion and nucleation usually control the rates of all solids deposition phenomena. Such effects can be put to good use in the production of special products such as cellulose yarn (rayon), by the precipitation of cellulose in filament form as it emerges as sodium cellulose xanthate liquid from the spinnerets into a bath containing sulphuric acid, which extracts the sodium as sodium sulphate, and the carbon disulphide. In a similar manner, the fabrication of aromatic polyimide fibres is performed by dissolving the polymer in concentrated sulphuric acid and forcing the solution through spinnerets into water. [Pg.212]

The sulphate, [Cr(NH3)4(H20)Br]S04, is also obtained from the bromide by decomposing it, in aqueous solution, with sodium sulphate and sulphuric acid. It is a red crystalline powder, easily soluble in water, and on heating the solution it decomposes into ammonia and chromic hydroxide. [Pg.98]

The kelp is crushed into lumps—say, one to two inches diameter—and extracted with water in rectangular iron vats with false bottoms, heated by steam. The liquid of sp. gr. 1 200 to l-255 is decanted into open iron boiling pans where it is evaporated down to a sp. gr. of 1 325 the salts—mainly potassium sulphate (50-60 per cent.) mixed with sodium sulphate and chloride—which separate by crystallization during the evaporation are removed. The hot liquid is run into cooling vats where crystals of potassium chloride separate. The liquid is again boiled down, and crystals consisting mainly of sodium chloride with 8 to 10 per cent, of sodium carbonate—and called kelp salt-—separate from... [Pg.42]


See other pages where Sodium sulphate and water is mentioned: [Pg.9]    [Pg.174]    [Pg.232]    [Pg.9]    [Pg.174]    [Pg.232]    [Pg.121]    [Pg.266]    [Pg.399]    [Pg.488]    [Pg.497]    [Pg.512]    [Pg.235]    [Pg.214]    [Pg.214]    [Pg.197]    [Pg.402]    [Pg.254]    [Pg.993]    [Pg.38]    [Pg.488]    [Pg.497]    [Pg.512]    [Pg.341]    [Pg.121]    [Pg.90]    [Pg.93]    [Pg.104]    [Pg.104]    [Pg.527]   
See also in sourсe #XX -- [ Pg.174 , Pg.176 ]




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