Magnesium chloride-alkali chlorides

Titanium metal also can be produced by electrolytic methods. In electrolysis, fused mixtures of titanium tetrachloride or lower chlorides with alkaline earth metal chlorides are electrolyzed to produce metal. Also, pure titanium can be prepared from electrolysis of titanium dioxide in a fused bath of calcium-, magnesium- or alkali metal fluorides. Other alkali or alkaline metal salts can be substituted for halides in these fused baths. Other titanium com-pouds that have been employed successfully in electrolytic titanium production include sodium fluotitanate and potassium fluotitanate. 

Metallic uranium can be prepared from its oxides or hahdes by reduction at high temperature. Uranium dioxide, UO2, or other oxides such as UO3 or UsOs may be reduced to uranium metal by heating with carbon, calcium or aluminum at high temperatures. Similarly, uranium tetrafluoride or other halides can be reduced to metal by heating with sodium, potassium, calcium, or magnesium at high temperatures. Alternatively, uranium tetrafluoride mixed with fused alkali chlorides is electrolyzed to generate uranium metal. 

C11H14O2, Mr 178.23, exists in cis (mp 35-36 °C) and in Irans mp 86°C) forms. The trans isomer has a sweet vanilla-like odor. Propenylguethol can be prepared from isosafrole by reaction with methyl magnesium chloride or by ethylation of isoeugenol followed by selective demethylation with alkali [169]. 

It has been shown that the f.p. curves of binary mixtures of the alkali chlorides show the probable formation of compounds, LiCl.RbCl, LiCl.CsCl, and LiC1.2CsCl. The curves of binary mixtures of lithium chloride with magnesium, calcium, strontium, or barium chloride show no signs of the formation of definite compounds,... 

Pour 3 ml of a 1 W alkali solution into each of two test tubes. Add about 1 g of solid ammonium chloride to one of them and dissolve it by shaking the tube. Pour 2 ml of a magnesium chloride solution into both tubes. Why does no precipitate form in one case Explain the observed phenomenon proceeding from the change in the hydroxyl ion concentration. 

The data published in the literature suggest that MgCl2 does not exist as Mg2+ cations and Cl" anions when dissolved in alkali chloride melts. These solvents act as ligand donors, and magnesium is found as anionic complexes in the melt. 

On the basis of emf data, obtained for the system MgCl2-KCl at 800°C, the equilibrium constant of reaction (109) was calculated to be 1.8 10 3. Such a low value of the dissociation constant is an indication of the high stability of the MgCl42 ion. The conclusion which results from these thermodynamic studies is that there are complex species present in melts of alkali chlorides containing magnesium chloride. 

Magnesium chloride is electrolyzed in a molten mixture with alkali chlorides at... 

The effect of other electrolytes is also of interest. Addition of divalent cations, e.g., in the form of calcium and magnesium chloride salts, results in precipitation of the anionic vesicles, which is also observed for micelles in water. There is, however, a significant trend within the alkali metal cations, e.g., from Na+ to Rb+. The larger rubidium ion has a promotional effect on the formation of vesicles, and indeed with Cs+, vesicles are already formed on the addition of trace amounts of salt. The relevant data are shown in Fig. 19.8. 

The effluent from the magnesium hydroxide process is a 25 percent calcium chloride brine. The water in the brine is boiled away with steam in triple-effect vacuum evaporators to make 32-45 percent CaCl2. Alkali chlorides precipitate in the evaporators and... 

Iridium Trichloride, IrCl3, is most conveniently prepared2 by heating the reduced metal—obtained by precipitation from an alkali chloriridate solution with magnesium—with sodium chloride in a current of chlorine at 600° to 620° C. The reaction is complete in a few minutes. The limits of stability of the salt under these conditions lie from below 100° C. up to 763° C. Above this latter temperature it dissociates in an atmosphere of chlorine into iridium dichloride and chlorine, and at still higher temperatures (773° C.) into the monochloride. 

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