Salt sodium sulfate-ammonium

The solubility data of carbon dioxide in aqueous solutions of binary mixed salts obtained in this study are summarized in Table I those for ternary mixed salts are summarized in Tables II, III, and IV. Figures 1 and 2 show the solubility data for the potassium chloride-calcium chloride and sodium chloride-sodium sulfate-ammonium chloride mixed solutions, respectively, which are representative of all the data. The salting-out effect was shown in all the systems studied. 

Figure 3 shows the plot for potassium chloride-calcium chloride binary salt system. Figure 4 shows the plot for sodium chloride-sodium sulfate-ammonium chloride ternary salt system. As shown in these figures, the plots of log(L0/L) vs. salt concentration all curve upward convexly, and the effects of these mixed salts on the solubility of carbon dioxide in the aqueous solutions do not show a direct correlation by the Setschenow Equation. These features are the same in all the mixed-salt systems considered here. 

K s is independent of pH and temperature, but depends on the nature of the protein and of the salt. Even so, these variations are not enormous with ammonium sulfate the variation of Ks with different proteins does not appear to be more than twofold. With the same protein and different salts, Ks decreases in the following order potassium phosphate, sodium sulfate, ammonium sulfate, sodium citrate, magnesium sulfate (Table I), f or chlorides the value is very much lower. 

Before the stmctural basis of chemical snbstances became established, compounds were named after people, places, or particular characteristics. Examples are Glauber s salt (sodium sulfate, discovered by J. R. Glauber), sal ammoniac (ammonium chloride, named after the ancient Egyptian deity Ammon from the temple near which the substance was made), and washing soda (sodinm carbonate, used for softening wash water). Today several million compounds are known and thousands of new ones are... 

Potassium Peroxydisulfate Potassium Persulfate Nitrogen Barium Sulfate Ammonium Peroxydisulfate Ammonium Persulfate Glauber s Salt Sodium Sulfate Decahydrate... 

Water-soluble peroxide salts, such as ammonium or sodium persulfate, are the usual initiators. The initiating species is the sulfate radical anion generated from either the thermal or redox cleavage of the persulfate anion. The thermal dissociation of the persulfate anion, which is a first-order process at constant temperature (106), can be greatly accelerated by the addition of certain reducing agents or small amounts of polyvalent metal salts, or both (87). By using redox initiator systems, rapid polymerizations are possible at much lower temperatures (25—60°C) than are practical with a thermally initiated system (75—90°C). 

Plants can also be pests that need to be controlled, particulady noxious weeds infesting food crops. Prior to 1900, inorganic compounds such as sulfuric acid, copper nitrate, sodium nitrate, ammonium sulfate, and potassium salts were used to selectively control mustards and other broadleaved weeds in cereal grains. By the early 1900s, Kainite and calcium cyanamid were also used in monocotyledenous crops, as well as iron sulfate, copper sulfate, and sodium arsenate. Prom 1915 to 1925, acid arsenical sprays, carbon bisulfate, sodium chlorate, and others were introduced for weed control use. Total or nonselective herbicides kill all vegetation, whereas selective compounds control weeds without adversely affecting the growth of the crop (see Herbicides). 

Demineralizers are often used to treat raw makeup water or condensate where high purity is required, such as in large central station boHers that operate at high steam pressures. Demineralizers employ a combination of cation and anion exchange to remove additional material, including sodium and ammonium cations. VirtuaHy aH salt anions, such as bicarbonate, sulfate, and chloride, are removed and replaced by hydroxide ions in the demineralizer. 

The flask is placed in an ice-salt mixture and the contents decomposed by the gradual addition of 300 cc. of saturated ammonium chloride solution and 100 cc. of water (Note 4). The aqueous layer is removed by means of a 1500-cc. separatory funnel and sufficient ether is added to dissolve the yellow precipitate. The total volume of ether solution is about one liter. This is washed with two 200-cc. portions of water, and the three aqueous layers are extracted consecutively with a loo-cc. portion of ether. The combined ether solution is dried over 30 g. of anhydrous sodium sulfate, coricentrated on the steam bath to a volume of about 200 cc., and cooled to room temperature. The product which crystallizes is collected with suction and washed with two 25-cc. portions of ether. The yield is 35-38 g. of light yellow product, m.p. 122-123°. The ether is completely removed from the combined filtrates by heating on the steam bath, and the black oil is allowed to stand overnight. The semi-solid mass is filtered with suction and washed with a minimum amount of cold ether. In this way an additional 6-7 g. of yellow material is obtained which melts at 119-121°. 

A 500-ml, three-necked, round-bottom flask is fitted with a mechanical stirrer, a thermometer, and a wide-stern (powder) funnel. The flask is cooled in an ice-salt bath and charged with 125 ml (approx. 0.5 mole) of 15% sodium hydroxide solution. When the stirred solution reaches -10°, 30% hydrogen peroxide (57.5 g, 52.5 ml, approx. 0.5 mole) previously cooled to -10° is added in one portion. The pot temperature rises and is allowed to return to —10° whereupon 37.5 g (0.25 mole) of phthalic anhydride (pulverized) is added rapidly with vigorous stirring. Immediately upon dissolution of the anhydride, 125 ml (approx. 0.25 mole) of cooled (-10°) 20% sulfuric acid is added in one portion. (The time interval between dissolution of the anhydride and the addition of the cold sulfuric acid should be minimized.) The solution is filtered through Pyrex wool and extracted with ether (one 250-ml portion followed by three 125-ml portions). The combined ethereal extracts are washed three times with 75-ml portions of 40% aqueous ammonium sulfate and dried over 25 g of anhydrous sodium sulfate for 24 hours under refrigeration. 

The Krafft point, i.e., the aqueous solubility, also depends greatly on the type of counterion [30,60,61]. For example, potassium salts have higher Krafft points than sodium or ammonium salts. Bivalent cations, like calcium and magnesium, raise the Krafft point. The rise is smaller for ester sulfonates than for alkyl sulfates [61]. 

Gelatin and albumin nanoparticles have been prepared through desolvation of the dissolved macromolecules by either salts (e.g., sodium sulfate or ammonium sulfate) or ethanol [179-182], This is, in principle, similar to a simple coacervation method. The particles can then be insolubilized through cross-linking with an optimum amount of aldehydes. These phase separation methods avoid the use of oils as the external phase. 

Protein separation by hydrophobic interaction chromatography is dependent upon interactions between the protein itself, the gel matrix and the surrounding aqueous solvent. Increasing the ionic strength of a solution by the addition of a neutral salt (e.g. ammonium sulfate or sodium chloride) increases the hydrophobicity of protein molecules. This may be explained (somewhat simplistically) on the basis that the hydration of salt ions in solution results in an ordered shell of water molecules forming around each ion. This attracts water molecules away from protein molecules, which in turn helps to unmask hydrophobic domains on the surface of the protein. 

Almost simultaneously, a pectinesterase was isolated from tomatoes of the Immuna variety.97 After extraction with 2% sodium chloride at pH 7.8, and fractional salting-out with ammonium sulfate, chromatography on DEAE-Sephadex A-50 removed a substantial proportion of colored contaminants and accompanying acid compo-... 

In a study of the pectinesterase from bananas,64,85,102 three pectinesterase fractions were obtained after respective extraction with water, 150 mM sodium chloride, and 150 mM sodium chloride of pH 7.5. The fractions obtained were further purified by fractional salting-out with ammonium sulfate, and chromatography on columns of DEAE- and CM-cellulose. A 50-fold purification was achieved, and the individual, purified fractions were characterized with respect to different effects of cations, inhibition by sucrose, and reaction kinetics. 

The combined carbon tetrachloride layers are shaken with 110 ml. of 151V ammonium hydroxide (Note 3), and the crystalline ammonium 1-adamantanecarboxylate that separates is collected on a Buchner funnel having a coarse fritted disk. The salt is washed with 20 ml. of cold acetone and suspended in 250 ml. of water. The suspension is made strongly acidic with 25 ml. of 12A hydrochloric acid and extracted with 100 ml. of chloroform. The chloroform layer is dried over anhydrous sodium sulfate and... 

Fig. 34. Modified sodium sulfate salt splitting process for the production of both ammonium sulfate and sodium hydroxide [13, 264-266]...

Table IV shows that potassium and sodium salts have been studied much more extensively than ammonium salts. However, we found that, for any one gas, differences in the coefficient between potassium and ammonium salts of the same anion and between sodium and ammonium salts of the same anion are nearly constant. For gases other than carbon dioxide, we have used data on bromides, chlorides, nitrates, and sulfates from a single investigator to obtain average differences (Table V). For carbon dioxide, such data were not available, and we used averages of results on chlorides, nitrates, and sulfates from different investigators.

Proteins crystallized from very low salt concentrations (examples are carboxypeptidase A and elastase) can often be treated exacdy like proteins crystallized from alcohol-water mixtures. Their low solubility in water allows them to be transferred from their normal mother liquor to a distilled water solution or to a solution of low (10-20%) alcohol concentration without disorder. It is advisable to carry out this transfer at near 0 C to further decrease the protein solubility. From this stage it is trivial to add alcohol while cooling, as described above. Complications arise, however, when the salt employed as a precipitant in the native mother liquor is insoluble in alcohols. The solution to this problem is to replace the salt by ammonium acetate at equivalent or higher ionic strength. Ammonium acetate is soluble up to 1 M in pure methanol, and is very soluble in nearly all alcohol-water mixtures, even at low temperature. It therefore provides a convenient substitute for salts such as sodium sulfate or sodium phosphate. 

Ammonium nitrate alternatively may be prepared by double decomposition reactions of ammonium salt with a nitrate salt e.g., ammonium sulfate and sodium nitrate ... 

The monazite sand is heated with sulfuric acid at about 120 to 170°C. An exothermic reaction ensues raising the temperature to above 200°C. Samarium and other rare earths are converted to their water-soluble sulfates. The residue is extracted with water and the solution is treated with sodium pyrophosphate to precipitate thorium. After removing thorium, the solution is treated with sodium sulfate to precipitate rare earths as their double sulfates, that is, rare earth sulfates-sodium sulfate. The double sulfates are heated with sodium hydroxide to convert them into rare earth hydroxides. The hydroxides are treated with hydrochloric or nitric acid to solubihze all rare earths except cerium. The insoluble cerium(IV) hydroxide is filtered. Lanthanum and other rare earths are then separated by fractional crystallization after converting them to double salts with ammonium or magnesium nitrate. The samarium—europium fraction is converted to acetates and reduced with sodium amalgam to low valence states. The reduced metals are extracted with dilute acid. As mentioned above, this fractional crystallization process is very tedious, time-consuming, and currently rare earths are separated by relatively easier methods based on ion exchange and solvent extraction. 

Proteins are salted out (precipitated) by ammonium or sodium sulfate (see Hofemeister series. Sect. 3.2). The structure of proteins... 

Usually, diazonium chlorides (from sodium nitrite and 37 wt % hydrochloric acid) are used as intermediates. They are treated with an alkaline tetrafluoroborate or tetrafluoroboric acid provided that its use is not prohibited by solubility problems, tetrafluoroboric acid delivers purer diazonium tetrafluoroborates than sodium or ammonium tetrafluoroborate.172 Diazonium hydrogen sulfates are also valuable auxiliary salts since they are insoluble in cold water and are obtained quantitatively and in a purer state than diazonium chlorides.118 Their warm, aqueous solutions deliver pure diazonium tetrafluoroborates when treated with tetrafluoroborate sources.137... 

Reduction of Ammonium Dichromate. Chromium(III) oxide can be obtained by thermal decomposition of ammonium dichromate. Above ca. 200 °C, a highly voluminous product is formed with elimination of nitrogen [3.48]. The pigment is obtained after addition of alkali salts (e.g., sodium sulfate) and subsequent calcination [3.49]. 

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