Hydrogen fluoride, liquid solubilities

Highly irritating and poisonous Very soluble in water. Liquid liberates heat as it dissolves in water. The entrapment of water in an anhydrous hydrogen fluoride cylinder can cause rapid generation of heat and pressure which can lead to an explosion. Containers should never be heated to >52°C. A liquid hydrogen fluoride spill area should not be entered unless protective clothing (impervious to the compound) and a self-contained gas mask are worn Fumes in air... 

Solubilities of the later lanthanide trifluorides are similar in liquid hydrogen fluoride and in water, though they are slightly more soluble in the former. Solubilities in liquid hydrogen fluoride (probably 98% HF) decrease steadily from a value of 4 x 10-5 mol EuFs per 100 g HF to 2.1 x 10-5 mol LuF3 per 100 g HF, at 0°C (281). 

Xylenes react reversibly to form complexes with boron trifluoride (BF3) in the presence of liquid hydrogen fluoride (HF). This fact can be utilized in the separation of w-xylene from its isomers, because the m-xylene complex is much more stable than the others and also more soluble in hydrogen... 

The liquid solubilities of propane, isobutane, and normal butane in hydrogen fluoride and the liquid solubilities of hydrogen fluoride in these three hydrocarbons in the temperature range 0 to 50°C. are given by the following equations. 

Benzene is about 2% soluble in HF under ordinary conditions but about 20% soluble at 50°. Oxygen, nitrogen, and sulfur containing organic compounds are in general very soluble in liquid hydrogen fluoride. 

Aromatic Compounds with Sulfides and Mercaptans. Alkyl sulfides and mercaptans function very similarly to ethers and alcohols. Hydrogen sulfide is produced and it escapes as a gas not being significantly soluble in liquid hydrogen fluoride. In this respect the technique of procedure is similar to that used for alkyl halides. 

Uranium(VI) fluoride is a colorless solid which sublimes at 56.2°C it does not exist as a liquid at atmospheric pressure. It is soluble in l,l,2-trichloro-l,2,2-trifluorocthane (Freon 113). hydrogen fluoride, and chlorohydrocarbons, although it will react31 slowly with the latter it cleaves some ethers12-13 and reacts vigorously32 with carbon disulfide to give sulfur tetrafluoride, carbon tetrafluoride, bis(trifluoromethyl) disulfide, and bis(trifluoromethyl) trisulfide. 

Liquid chlorine trifluoride is soluble in all proportions in liquid hydrogen fluoride. The phase equilibria of the system, chlorine trifluoride-hydrogen fluoride, were investigated by McGill et al. [95],... 

The starting materials can be recovered unchanged by the addition of water to the sulfuric acid solution. With olefins the situation is complicated by accompanying chemical reactions, but it is significant that aromatic hydrocarbons are soluble in liquid hydrogen fluoride while saturated hydrocarbons arc not.4 This fact suggests the electron donor capacity which equations 3 and 6 attribute to an unsaturated linkage. 

Properties Colorless, fuming gas or liquid. Very soluble in water. The liquid and gas consist of associated molecules. The vapor density corresponds to hydrogen fluoride only at high temperatures. Fp —83C, bp 19.5C, d (liquid) 0.988 (14C), sp vol 17 cu ft/lb (21.1C, 1 atm). Nonflammable. 

The rules given in Table 4.2 (p. 113) allow us to predict the solubility of a particular ionic compound in water. When sodium chloride dissolves in water, the ions are stabilized in solution by hydration, which involves ion-dipole interaction. In general, we predict that ionic compounds should be much more soluble in polar solvents, such as water, liquid ammonia, and liquid hydrogen fluoride, than in nonpolar solvents, such as benzene and carbon tetrachloride. Since the molecules of nonpolar solvents lack a dipole moment, they cannot effectively solvate the Na and Cl ions. Solvation is the process in which an ion or a molecule is surrounded by solvent molecules arranged in a specific manner. The process is called hydration when the solvent is water.) The predominant intermolecular interaction between ions and nonpolar compounds is ion-induced dipole interaction, which is much weaker than ion-dipole interaction. Consequently, ionic compounds usually have extremely low solubility in nonpolar solvents. 

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