Strength chloride concentration

Solutes have differing solubilities in different liqnids dne to variations in the strength of the interaction of solnte molecnles with those of the solvent. Thus, in a system of two immiscible or only partially miscible solvents, different solutes become unevenly distribnted between the two solvent phases, and as noted earlier, this is the basis for the solvent extraction technique. In this context, solvent almost invariably means organic solvent. This uneven distribution is illustrated in Fig. 1.3, which shows the extractability into a kerosene solution of the different metals that appear when stainless steel is dissolved in aqueous acid chloride solution. The metals Mo, Zn, and Fe(III) are easily extracted into the organic solvent mixture at low chloride ion concentration, and Cu, Co, Fe(ll), and Mn at intermediate concentration, while even at the highest chloride concentration in the system, Ni and Cr are poorly extracted. This is used industrially for separating the metals in super-alloy scrap in order to recover the most valuable ones. 

Extraction of metals from chloride solutions into kerosene containing trioctyl amine (TOA), as illustrated by Fig. 1.3, has found application in the production of pure Co and Ni metals from their ores, as discussed in Chapter 11. The aqueous phase contains the Co and Ni in addition to other metals in chloride solution, where the chloride concentration goes to 300 g/L (i.e., about 8.5 M). At this high aqueous ionic strength, a rigorous mathematical treatment of the system would require the use of activities in order to explain the extraction... 

The first step is to reduce label clutter. Only essential information, such as the brand and generic names, strength or concentration, and warnings, should appear prominently on the front label. Numerous deaths have been prevented through the addition of a warning to concentrated vials of injectable potassium chloride, for example. Another step includes the use of typeface to enhance distinctive portions of look-alike drug names on look-alike packaging. 

Figure A-11 The variation of the extraction coefficient with increasing chloride concentration (0.3397 to 0.5336 M) at constant acidity and ionic strength.

Before applying this equation to the data published in [70HALA AN], two further simplifications should be used. With increasing chloride concentration the ionic strength of the solution expressed in molarity is constant, but in the molal scale it changes. Since no density data are available for such an electrolyte mixture, I, was calculated using the equation ... 

However, an equally good description may be obtained by using the SIT model (strict ion interaction approach excluding the formation of chloride complexes) in particular in perchlorate-chloride mixtures of high ionic strength and chloride concentration. Fitting the data at / = 2.0 through 6.0 M yields s(Th", CF) values very close to the value of e(Th", Cl ) = (0.25 + 0.03) kg-mol selected by this review, cf. Table VIII-19. 

The difference between activity and concentration is illustrated by Figure 23-17, where the lower curve gives the change in potential of a calcium electrode as a function of calcium chloride concentration (note that the activity or concentration scale is logarithmic). The nonlinearity of the curve is due to the increase in ionic strength — and the consequent decrease in the activity coefficient of the calcium - as the electrolyte concentration becomes larger. When these concentrations are convened to activities, the data produce the upper line with the nernslian slope of 0,fl296 (0,0592/2). 

Figure 2. Effect of sodium chloride concentration ionic strength) on initial polymerization rate of methacrylic acid. The pH was 10.5 adjusted with NaOH. Reproduced with permission from ref 35. Copyright 1977 Huethig...

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