Electrolytes and hydrates

Nonaqueous electrolyte solutions are analogous to aqueous solutions they, too, are systems with a liquid solvent and a solute or solutes dissociating and forming solvated ions. The special features of water as a solvent are its high polarity, e = 78.5, which promotes dissocation of dissolved electrolytes and hydration of the ions, and its protolytic reactivity. When considering these features, we can group the nonaqueous solvents as follows ... 

O. Ya. Samoilov, Structure of Aqueous Solutions of Electrolytes and Hydration of Ions, Izdat. Akademii Nauk SSSR, Moscow, 1957 (in Russian). 

Samoylov OYa (1957) Stmcmre of water solutions of electrolytes and hydration of ionics. Academy of Science of the USSR, Moscow (in Russian)... 

At the air-water interface, the molecules of fatty acid and its anions form the negatively charged plate of the electric double layer (for the case when water does not contain any additional electrolytes). And hydrated protons (i.e., H3O+) form the diffuse part of the electrical double layer, that is, these ions forming a second plate of the electrical condenser. And the local proton density depends exponentially on the electrostatic potential according to the following equation ... 

Cellophane or its derivatives have been used as the basic separator for the silver—ziac cell siace the 1940s (65,66). Cellophane is hydrated by the caustic electrolyte and expands to approximately three times its dry thickness iaside the cell exerting a small internal pressure ia the cell. This pressure restrains the ziac anode active material within the plate itself and renders the ziac less available for dissolution duriag discharge. The cellophane, however, is also the principal limitation to cell life. Oxidation of the cellophane ia the cell environment degrades the separator and within a relatively short time short circuits may occur ia the cell. In addition, chemical combination of dissolved silver species ia the electrolyte may form a conductive path through the cellophane. 

Butt, H.J., Measuring electrostatic. Van der waals, and hydration forces in electrolyte-solutions with an atomic force microscope. Biophys. J., 60(6), 1438-1444 (1991). 

Intravenous replacement solutions are a source of electrolytes and water for hydration (Normosol M Ringer s Injection, Lactated Ringer s, Plasma-Lyte R), and used to facilitate amino acid utilization and maintain electrolyte balance (Lypholyte, Multilyte, TPN Electrolytes). Dextrose and electrolyte solutions such as Plasma-Lyte R and 5% dextrose are used as a parenteral source of electrolytes, calories, or water for hydration. Invert sugar-electrolyte solutions, such as Multiple Electrolytes and Travert 5% and 10%, contain equal parts of dextrose and fructose and are used as a source of calories and hydration. 

Metallic Mg is produced industrially using both electrolytic and thermal reduction methods. The electrolytic processes differ primarily in the choice of electrolyte—anhyd MgClj, partially hydrated MgClj x HjO and MgO. The more important thermal reduction processes use FeSi, A1 alloys or C as reducing agents. 

The stability of a colloid such as gelatin in water is determined by the electric charge and hydration. The addition of large amounts of electrolytes to colloids (biopolymers) causes... 

Samoilov, O. Ya., Structure of Aqueous Electrolyte Solutions and Hydration of Ions, Consultants Bureau, New York, 1965. 

Very interesting behavior of incorporating anions can be observed when a multicomponent electrolyte is used for oxide formation. Here, anion antagonism or synergism can be observed, depending on the types of anions used. The antagonism of hydroxyl ions and acid anions has been observed in a number of cases. Konno et a/.181 have observed, in experiments on anodic alumina deterioration and hydration, that small amounts of phosphates and chromates inhibit oxide hydration by forming monolayer or two-layer films of adsorbed anions at the oxide surface. Abd-Rabbo et al.162 have observed preferential incorporation of phosphate anions from a mixture of phosphates and chromates. 

The abnormal rotation and the anomalous dispersion cannot be accounted for satisfactorily on the basis of polymerization, electrolytic dissociation hydrates, lactones of the ordinary type, or of a structural reversal of the asymmetric carbon atom. 

Raji Heyrovska [18] has developed a model based on incomplete dissociation, Bjermm s theory of ion-pair formation, and hydration numbers that she has found fits the data for NaCl solutions from infinite dilution to saturation, as well as several other strong electrolytes. She describes the use of activity coefficients and extensions of the Debye-Hiickel theory as best-fitting parameters rather than as explaining the significance of the observed results. ... 

Water management is one of the most critical and widely studied issues in PEFC. Water management is referred to as balancing membrane hydration with flooding avoidance. These are two conflicting needs to hydrate the polymer electrolyte and to avoid flooding in porous electrodes and GDL for reactant/ product transport. 

From the point of view of chemical modeling, aqueous solutions are treated as electrolytic solutions —i.e., solutions in which solutes are present partially or totally in ionic form. Speciation is the name for the characteristic distribution of ion species in a given aqueous solution in the form of simple ions, ionic couplings, and neutral molecules. Solutes in aqueous solutions are defined as electrolytes and may be subdivided into nonassociated and associated. Nonassociated electrolytes are also defined as strong and mainly occur in the form of simple or simply hydrated ions. An example of a strong electrolyte is the salt NaCl, which, in aqueous solution of low ionic strength, occurs in the form of completely dissociated Na and CN ions. 

Overdosage can lead to lethargy and coma without changes in electrolytes or hydration. 

Clearly, a detailed and comprehensive analysis of dynamical effects of the environment, in particular of fluctuations of the electrostatic potential in the interior of the DNA duplex created by the hydrated sodium ions of surrounding electrolyte, and the influence of these fluctuations on charge transfer parameters is desirable. 

Clays Magnesium aluminum silicate (V eegum) Anionic 0.5-2.5 Disperses and hydrates readily. Hot water increases rate of hydration 3-11 Plastic/ thixotropy Partially flocculated by electrolytes and incompatible with acidic solution [Pg.168]

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