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Melts simple ionic

The classification system described earlier is limited to the simplest kinds of individual melts and is not intended to include mixtures. However, molten mixtures of these different classes of compounds are often more practical solvents than the melts of the individual compounds, due to their much lower melting points and other favorable properties, and this system of classification can usually be extended to these mixtures. For example, the very popular molten LiCl-KCl eutectic mixture is simply a binary ionic melt, whereas molten NaN03-KN03-LiN03 is a ternary polyanionic melt. Interestingly, the equimolar molten mixture of the simple ionic salt NaCl (a) and the molecular compound A1C13 (d) produces a simple polyanionic salt melt (b) composed of Na+ and A1C14 ions ... [Pg.512]

A number of molten salt systems [e.g., the simple ionic system Ca(N03)2-KN0j], have the property of being able to be supercooled, i.e., to remain liquid at temperatures below the melting point down to a final temperature. This is called the glass transition temperature, and at this temperature the salts form what is called a glass. This glass is only apparently solid. It is a highly disordered substance in which a liquid structure... [Pg.642]

Simple ionic liquids have viscosities in the range of 1 to 5 centipoises (cP). However, when there is an association of ions into aggregates, as, for example, in ZnCl2 near the melting point, the viscous force-resisting flow of the melt increases above that noted for simple liquids. Such complex ionic liquids are discussed later (Section 5.8). [Pg.654]

A measure of understanding has been gained on the structure and transport properties of simple ionic liquids. In practice, however, mixtures of simple liquid electrolytes are more important than pure systems such as liquid sodium chloride. One reason for their importance is that mixtures have lower melting points and hence provide the advantages of molten salts,but with a lessening of the difficulties caused by high temperatures. What happens when two ionic liquids, for example, CdClj and KCl, are mixed together ... [Pg.694]

It has just been argued that the conductivities of simple ionic liquids, on the one hand, and liquid sihca and water, on the other, are vastly different because a fused salt is an unassociated liquid (it consists of individual particles) whereas both molten silica and water are associated liquids with network structures. What is the situation with regard to the viscosities of fused salts, water, and fused silica Experiments indicate that whereas water and fused NaCl have similar viscosities not far above the melting points of ice and solid salt, respectively, fused silica is a highly viscous liquid (Table 5.46). Here then is an interesting problem. [Pg.728]

A fuller knowledge of the structure and bonding in silicate melts should enable detailed description and prediction of the chemical processes involved in magmatic crystallization and of the partitioning of elements between melt and crystals. A large body of experimental data is, in fact, available on this subject, but the only significant contributions so far made by application of bonding theories center on the simple ionic models... [Pg.393]

The interest in ILs has been generated due to their unique properties and potential uses in areas as diverse as synthesis, biocatalysis, electrochemistry, etc. Thus, this class of molecules is increasingly employed in organic chemistry, material sciences and physical chemistry [3,4], ILs are salts - substances composed exclusively of cations and anions. This fact differentiates them from simple ionic solutions, in which ions are dissolved in a molecular medium. They are also different from inorganic molten salts because their melting points are lower than 100°C (most of them exist in liquid form at or near room temperature). [Pg.336]

There is thus good experimental evidence that silicate melts are ionic liquids containing relatively free cations and mixtures of polymeric silicate anions. In a previous chapter Kleppa has reviewed what is known of the mixing properties of simple molten salts. The applications of these principles to melts containing a large number of different polyanions requires the introduction of methods developed by organic polymer chemists (Flory, 1936, 1952). Before describing the polymer models which have been applied to silicate melts it will be useful to review briefly the use of the terms acidic and basic as applied to oxides or melts. [Pg.305]

From Section 2.1 it has become very clear that the synthesis of an ionic liquid is in general quite simple organic chemistry, while the preparation of an ionic liquid of a certain quality requires some know-how and experience. Since neither distillation nor crystallization can be used to purify ionic liquids after their synthesis (due to their nonvolatility and low melting points), maximum care has to be taken before and during the ionic liquid synthesis to obtain the desired quality. [Pg.21]

Because of the variety of ionic species present in the melt, the reactions that take place at the electrodes are considerably more complex than the simple representations given here. Nevertheless, the net reaction is the one given by these simplified reactions 4 e I f) + 6 0 m slt) + 3 (. ) -> 3 C02(g) + 4 Al(/)... [Pg.1516]


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Ionic melts

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