Hygroscopicity and Solubility

The solubility of mono- and oligosaccharides in water is good. However, anomers may differ substantially in their solubility, as exemplified by a- and P- lactose (cf. 10.1.2.2). Monosaccharides 

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The distilled product can be used as a catalyst, although it usually has a relatively strong phenylphosphine odor. It is quite deliquescent, and it has not been satisfactorily recrystallized. If rigorous purification and deodorization are desired, the product is dissolved in water, a small amount of hydrogen peroxide is added to oxidize the phosphines, the solution is reneutralized, saturated with salt, and extracted with chloroform, and the product is refractionated. One cycle is normally enough. Pure product is essentially odorless, very hygroscopic, and soluble in polar solvents. 

Reactions with halogens are slow at room temperature but progress rapidly above 200°C forming ytterbium trihalides. All the trihalides namely, the YbCls, YbBrs, and Ybis with the exception of trifluoride, YbFs, are hygroscopic and soluble in water. 

The melting point of DADMAC was found to be 151-152.5 °C [32]. The crystalline product is very hygroscopic and soluble in water, alcohols, acetone, 1-me-thyl-2-pyrrolidone, tetramethyl urea, or dimethylformamide. XH-NMR analysis of the pure DADMAC shows the following signals s 6.93 (N-CH3) d 6.05 (N-CH2-) m 3.53-4.50 (-CH=CH2) ppm [32]. 

Otsuka, M. and Kaneniwa, N. (1983). Hygroscopicity and solubility of noncrystalline cephsffi enp. Pharm. 

The triamine is extremely hygroscopic and soluble in both water and n-heptane. Because of this amazing solubility range, it cannot be crystallized easily. The crude triamine can be partially purified by chromatography on a column of alumina, with 50 50 (v/v) benzene-chloroform as the eluent, but is extremely difficult to isolate in a pure state. 

By dissolving iridium black or the dioxide in hydrochloric acid. The solution is concentrated and any trichloride converted into tetrachloride by addition of aqua regia. The product is dried in vacuo, whereby a brownish black amorphous residue is obtained which is very hygroscopic and soluble in water. 

The crystals have density at 20-7° C., 4-68. They are very hygroscopic and soluble in water. Chemically, uranium hexafluoride is highly reactive, vigorously attacking alcohol, ether, or benzene, in the... 

Uranyl chloride, UOjClj, is formed by heating U02 to red heat in a stream of dry chlorine. It forms a yellow crystalline mass, which is hygroscopic and soluble in water. The water solution on slow evaporation forms a monohydrate. The anhydrous uranyl chloride is stable if it is kept away from moisture. The water solution has an acid reaction and upon heating liberates HC1. It forms double salts with the alkali chlorides, such as 2 KC1 UO2CI2 2 H2O. 

The sulfate obtained in this manner (TiOgtSOg = 1 1.07) is colorless and free of HCl. It is hygroscopic and soluble in water, yielding a clear solution. 

Malic acid has recently been introduced in effervescent formulations because of its smooth and light taste. It is highly hygroscopic and soluble but has less acid strength than tartaric or citric adds. 

The solid appears to be a mixture of the complexes CH,COOH.BF, and 2CH COOH.BF,. The latter appears to be a liquid and is alone soluble in ethylene dichloride the former is a solid. The solid moiioocetic acid complex is obtained by saturating an ethylene dichloride solution of acetic acid with boron trifluoride, filtering and washing the precipitate with the solvent it is hygroscopic and should be protected from moisture. It may be used as required 0-75 mol is employed with 0-26 mol of ketone and 0 6 mol of anhydride. 

The physical properties of cyanoacetic acid [372-09-8] and two of its ester derivatives are Hsted ia Table 11 (82). The parent acid is a strong organic acid with a dissociation constant at 25°C of 3.36 x 10. It is prepared by the reaction of chloroacetic acid with sodium cyanide. It is hygroscopic and highly soluble ia alcohols and diethyl ether but iasoluble ia both aromatic and aUphatic hydrocarbons. It undergoes typical nitrile and acid reactions but the presence of the nitrile and the carboxyUc acid on the same carbon cause the hydrogens on C-2 to be readily replaced. The resulting malonic acid derivative decarboxylates to a substituted acrylonitrile ... 

Sodium Borohydride. Sodium borohydride [16940-66-2] is a thermally stable, white crystalline soHd that decomposes in vacuo above 400°C. The heat of formation is —192 kJ/mol (—45.9 kcal/mol). NaBH is hygroscopic and absorbs water rapidly from moist air to form a dihydrate that decomposes slowly to sodium metaborate and hydrogen. It is soluble in many solvents including water, alcohols, Hquid ammonia and amines, glycol ethers, and dimethyl sulfoxide. 

Iron(III) iodide [15600-49-4], Fefy, is prepared by the oxidative photodecarbonylation of diiodotetracarbonylkon(II) ki the presence of dkodine (7). The black soHd obtained is extremely hygroscopic, spariagly soluble only ki dichloromethane, and decomposes to kon(II) iodide and dkodine when exposed to donor solvents such as tetrahydrofuran, acetonitrile, water, or pyridine. It also decomposes when exposed to light. 

Niobium Pentabromide. Niobium pentabromide is most conveniently prepared by reaction of bromine with niobium metal at ca 500°C. It is a fairly volatile yellow-red compound that is hygroscopic and readily hydrolyzes. It is soluble in water, alcohol, and ethyl bromide. 

Because monocalcium phosphate is incongmently soluble, it is typically contaminated with various amounts (6—10%) of dicalcium phosphate and free phosphoric acid resulting from in-process disproportionation of the monocalcium salt. Free phosphoric acid may render the product hygroscopic, and absorbed water plus acid catalyzes further decomposition to additional free acid and dicalcium phosphate. For this reason, industrial monocalcium phosphate may contain some dicalcium phosphate resulting from excess lime addition and then aged to ensure the removal of residual free phosphoric acid. 

Rubidium metal alloys with the other alkaU metals, the alkaline-earth metals, antimony, bismuth, gold, and mercury. Rubidium forms double haUde salts with antimony, bismuth, cadmium, cobalt, copper, iron, lead, manganese, mercury, nickel, thorium, and 2iac. These complexes are generally water iasoluble and not hygroscopic. The soluble mbidium compounds are acetate, bromide, carbonate, chloride, chromate, fluoride, formate, hydroxide, iodide. 

Zinc chloride melts at 275°C, bods at 720°C, and is stable in the vapor phase up to 900°C. It is very hygroscopic, extremely water-soluble, and soluble in organic Hquids such as alcohols, esters, ketones, ethers, amides, and nitrides. Hydrates with 1, 1.5, 2.5, 3, and 4 molecules of water have been identified and great care must be exercised to avoid hydration of the anhydrous form. Aqueous solutions of zinc chloride are acidic (pH = 1.0 for 6 M) and, when partially neutralized, can form slightly soluble basic chlorides, eg, ZnCl2 4Zn(OH)2 [11073-22-6] and Zn(OH)Cl [14031-59-5]. Many other basic chlorides have been reported (58). 

Potassium hydroxide is the principal electrolyte of choice for the above batteries because of its compatibiUty with the various electrodes, good conductivity, and low freezing point temperature. Potassium hydroxide is a white crystalline substance having a mol wt = 56.10 density = 2.044 g/mL, and mp = 360° C (see Potassium compounds). It is hygroscopic and very soluble in water. The most conductive aqueous solution at 25 °C is at 27% KOH, but the conductivity characteristics are relatively flat over a broad range of concentrations. 

Beryllium fluoride is hygroscopic and highly soluble in water, although its dissolution rate is slow. FluoroberyUates can be readily prepared by crystallization or precipitation from aqueous solution. Compounds containing the BeP ion are the most readily obtained, though compounds containing other fluoroberyUate ions can also be obtained, eg, NH BeF, depending upon conditions. 

Potassium borohydride is similar in properties and reactions to sodium borohydride, and can similarly be used as a reducing agent for removing aldehydes, ketones and organic peroxides. It is non-hygroscopic and can be used in water, ethanol, methanol or water-alcohol mixtures, provided some alkali is added to minimise decomposition, but it is somewhat less soluble than sodium borohydride in most solvents. For example, the solubility of potassium borohydride in water at 25° is 19g per lOOmL of water (as compared to sodium borohydride, 55g). 

Calcium chloride (anhydrous) [10043-52-4] M 111.0, m 772 , b >1600 , d 2.15. Available as fused granules or cubic crystals. It is very hygroscopic. Very soluble in H2O (exothermic), and EtOH. Store in a tightly closed container. 

The other halides of Zn and Cd are in general hygroscopic and very soluble in water ( 400g per lOOcm for ZnXa and 100g per lOOcm for CdXa). This is at least partly because of the formation of complex ions in solution, and the anhydous forms are best prepared by... 

The dried product is a reddish brown, amorphous solid presenting a glistening surface upon fracture. The dry product is somewhat hygroscopic and is freely soluble in water to give a stable solution. The following paragraph gives an alternative preparation. 

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