Anionic composition

Fig. 3. Cation and anion composition of extracellular and intracellular 1 fluids.

In report separately discuss the peculiarities of determination of the anion composition of the solid solutions, that conditioned by ability of diphosphate anion to destruction in water solutions. In given concrete case by most acceptable method of control of the diphosphate anion in the hydrated solid solutions is a traditional method of the quantitative chromatography on the paper. Methodical ways which providing of minimum destruction of the diphosphate anion in the time of preparation of the model to analysis (translation in soluble condition) and during quantitative determination of the P.,0, anion are considered. 

All of these three properties of the oxide films on metals are influenced by the anion composition and pH of the solution. In addition the potential of the metal will depend on the presence of oxidising agents in the solution. Inhibition of corrosion by anions thus requires an appropriate combination of anions, pH and oxidising agent in the solution so that the oxide film on the metal is stable (the potential then lying between the Flade potential and the breakdown potential), and protective (the corrosion current through the oxide being low). 

Comparison of Ca3(POi)2, Ca(C204), and Mg3(P04)2. The effects of cation and anion composites were tested by comparing the dissolution of Ca3(P04)2, Ca(C204), andMg3(P04)2 at pH 7 (Table 10). The dissolution of Ca3(P04)2 is achieved more effectively with X than with EDTA. However, when the anion is oxalate, the dissolution of Ca2+ is drastically reduced with X. EDTA can dissolve Ga(C204) to the same extent as Ca3(P04)2, i.e. the anion effect is insignificant. A better separation of Ca2+ from oxalate anion may be achieved by EDTA. 

The anionic composition of the cathodic product is not the only parameter that can be controlled through electrolysis conditions. Grinevitch et al. [559] reported on the investigation of the co-deposition of tantalum and niobium during the electrolysis of fluoride - chloride melts. Appropriate electrodeposition conditions were found that enable to obtain either pure niobium or alloys. 

Most of the data from the complete set at each station do not show a substantial charge imbalance, considering that the cationic composition should be balanced by the anionic composition. The magnitude of the imbalance is best seen by using the Normalised Inorganic Charge Balance (NICB = X — X+/X + X+ 100). Most points plot within the 5% field with a mean NICB close to 0% and a standard deviation of 2% for all the Ebro monitoring stations and the tributaries. 

The anionic composition of the HF-SbFs system as a function of SbFs concentration is shown in Figure 2.15. 

Figure2.15. The anionic composition of the HF- SbF-, system. ( ) SbF6 ( ) Sb2Fn ( ) Sb3F16- ( ) Sb4F2r (O) SbFs.87...

Attempts were made to determine experimentally the nature of the influence of the anion composition of volcanogenic waters on the removal of iron from volcanic rocks. For this purpose samples of basalt, andesite, and dacite were leaehed with sulfuric, hydrochloric, and carbonic acid solutions under conditions of high temperature and pressure (Naboko and Sil chenko, 1960). 

BFr< SbFg. This order parallels that observed for olefin solubility in concentrated silver salt solutions (40, 193). Structural investigations of crystalline silver-olefin complexes have shown a nearly covalent bond between the silver and the nitrate ions (28, 399), but an electrostatic bond only between silver and fluoroborate ions (537). Consequently, the differing complex stability may be largely attributable to the differences in the energy required for the expansion which permits incorporation of the olefin molecule into the salt lattice. These differences will depend upon the anion composition (537), geometry, and size. Similarly, the degree of silver ion-anion association in concentrated solutions will vary with the anion and a similar explanation can account for the dependence of olefin solubility on the anion. In dilute solutions, however, the silver ion environment and thus the olefin solubility may be essentially independent of the anion (193). 

Figure 5 Anion compositional trends in the Great Basin, USA. The arrow indicates general trend of increasing compositional evolution of waters (Hutchinson (1957) reproduced from A Treatise on Limnology, 1957).

It is generally agreed that most of the chloride in basinal brines has been derived from some combination of the subsurface dissolution of evaporites (e.g., Kharaka et al., 1985 Land, 1997) and the entrapment and/or infiltration of evaporated seawater (e.g.. Carpenter, 1978 Kharaka et al., 1987 Moldovanyi and Walter, 1992). Dissolution of halite produces waters dominated by sodium chloride. Evaporation of seawater produces waters having the general trends shown for ion-Br (Figure 5), Na-Cl (Figure 3) and Ca-Cl (Figure 4), but most formation waters have neither the cation (nor anion) composition of an... 

At salinities of less than 1 X lO" mg and relatively shallow depths, the anionic composition of subsurface water is highly variable and can be dominated by sulfate, bicarbonate, chloride, or even acetate (Hem, 1985 Drever, 1997). Shallow groundwater generally is dominated by sulfate, which is replaced by bicarbonate as the dominant species in deeper meteoric groundwater. Acetate may comprise a large portion of total anions, especially in the Na-Cl-CH3COO-type waters that are present mainly in Cenozoic reservoir rocks at temperatures of 80-120 °C. In these waters, acetate and other organic acid anions (see Section 5.16.3.5) can reach concentrations of up to 1 X 10 mg and contribute up to 99% of the measured alkalinities (Willey et al., 1975 Kharaka et al., 2000). 

Apparently, formation of actinide (IV) compounds with more complex cationic and anionic compositions with the monazite or zircon (xenotime) structure types is possible. These compounds can be considered to be solid solutions. The possibility of forming this kind of compound is realized in the minerals mentioned above. These minerals are characterized by the complex cation compositions monazite - (La, Ce, other lanthanides, Y, Ca, Th)(P, Si)04, xenotime - (Y, lanthanides. Sc, Zr, Th, U)(Si, P)04 zircon - (Zr, Hf, Th, U, lanthanides, Ca, Fe, Nb, Ta)(Si,P)04 [71]. The ionic radii and cationic proportions, anionic sizes and synthesis conditions affect the formation of each type considered. 

Golodnitsky et al. found that inhibition of the more positive metal deposition by the less noble one does not depend on the anion composition of the electrolyte [73]. 

Owing to their polymeric character, silicate melts belong to the solutions of type II, which do not follow Raoult s law. The classic regular solution approach is not applicable, since the limiting laws are not obeyed. The Temkin s model of ideal ionic solution, which has been widely applied in molten salt systems, cannot be used, since the real anionic composition, owing to a broad polyanionic distribution, is not known a priori. 

Easy reducibility and reoxidizability by means of molecular oxygen. This allows them to be used as catalysts for liquid-phase or gas-phase multi-electron oxidations. The redox properties of these materials can be affected properly by modifying the anionic composition (for instance, by substitution of some Mo " " cations by or the cationic composition. Several different cations can be introduced in the structure, i.e. alkali and alkaline earth metals, ammonium, divalent and trivalent metals such as Cu, Co, VO. ... 

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