Electrolytes fused

Fluorine cannot be prepared directly by chemical methods. It is prepared in the laboratory and on an industrial scale by electrolysis. Two methods are employed (a) using fused potassium hydrogen-fluoride, KHFj, ill a cell heated electrically to 520-570 K or (b) using fused electrolyte, of composition KF HF = 1 2, in a cell at 340-370 K which can be electrically or steam heated. Moissan, who first isolated fluorine in 1886, used a method very similar to (b) and it is this process which is commonly used in the laboratory and on an industrial scale today. There have been many cell designs but the cell is usually made from steel, or a copper-nickel alloy ( Monel metal). Steel or copper cathodes and specially made amorphous carbon anodes (to minimise attack by fluorine) are used. Hydrogen is formed at the cathode and fluorine at the anode, and the hydrogen fluoride content of the fused electrolyte is maintained by passing in... 

Production. MetaUic strontium was first successfully produced by the electrolysis of fused strontium chloride. Although many attempts were made to develop this process, the deposited metal has a tendency to migrate into the fused electrolyte and the method was not satisfactory. A more effective early method was that described in Reference r5. Strontium oxide is reduced thermally with aluminum according to the following reaction ... 

It should, however, be noted that the electrical double layer at the metal-fused electrolyte interface does not have this character, in spite of the ion concentration being high. In this system, the space charge includes several ion layers at the interface. 

Brockman, C. J., Fused electrolytes—an historical sketch, . Chem Educ, 4,... 

One of the main reasons why chemical condensers and electrolytic rectifiers have not been more popular is the sloppiness of the liquid electrolyte. Perhaps some experimenters may overcome this disadvantage by using some form of jelly or fused electrolyte. Fused sodium phosphate has been used for the electrolyte of an aluminum cell rectifier with very good results. It would seem that much better efficiency would be obtained when using the rectifier for B eliminators, because the current used is much less than for charging batteries. 

Faraday s law holds for solid electrolytic conductors as well as for fused electrolytes and solutions this is shown by the results of Tubandt and Eggert (1920) on the electrolysis of the cubic form of silver iodide quoted in Table III. The quantities of silver deposited in an ordinary... 

G.J. Janz and F. Saegusa, The Oxygen Electrode in Fused Electrolytes, Electrochim. Acta 7 (1962) 393-398. 

Some theoreticians believe that the best approach to electrolyte theory would be to work downwards from the fused electrolyte to the highly concentrated solution, to the concentrated... 

Obtained by fusing electrolytic Cu with pure Te in a crucible under a protective layer of NaCl and KCl. 

The composition of the solvent has a dramatic influence on the electrodeposition process of refractory metals in fused electrolytes [1]. Also, in contrast to other metals prepared by electrolysis at high temperatures such as alkali metals, magnesium or aluminium, all the refractory metals exist in a variety of oxidation states. The metal chlorides undergo disproportionation reactions leading to formation of seemingly colloidal metal in the melt. The... 

The aim of the present paper was to commence a systematic study of the thermodynamics properties of solutions of titanium ions in various fused electrolytes. Experimental determinations were carried out using dynamic electrochemical techniques such as cyclic voltammetry or chronopotentiom-etry in alkali chloride mixtures. 

In 1854 Henri Etienne Sainte-Claire Deville prepared silicon by electrolysis in coimection with his pioneer work with aluminum. He used a fused electrolyte of impure sodium aluminum chloride. The aluminum metal, obtained at the cathode, contained 10% silicon. When dissolved in add, bright silicon laminae stayed undissolved. It is interesting to note that Deville expressed the opinion that the element silicon is not a real metal. 

Examples of the products of the electrolysis of molten or fused electrolytes are shown in Table 9.9. 

Kumar A (1993) Surface traision, viscosity, vapor pressine, density, and sound velocity for a system miscible continuously from a pure fused electrolyte to a nonaqueous liquid with a low dielectric constant anisole with tetra-n-butyl-ammonium picrate. J Am Chem Soc... 

The cells consist of iron containers with carbon lining, which serve as cathode. Molten aluminium collects on the floor of the cell, where it can be tapped off. Above this is the fused electrolyte, into which the... 

It is possible to discharge sodium electrolytically from an aqueous solution if a mercury cathode is used. On the basis of the standard electrode potentials [E (Na, Na) =-2.71V], the decomposition of water to form hydrogen at the cathode would be a far easier process even when allowance is made for the high hydrogen overpotential (q.v.) at mercury. However, the fact that sodium forms intermetallic compounds with mercury which are soluble in mercury and diffuse away so reduces the activity of the sodium at the cathode surface, and its tendency to re-ionise that the discharge of sodium becomes the preferred process. This method is not used commercially because of the high cost of extraction of sodium from its amalgam, and recourse is had to fused electrolytes. 

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