Lithium ionic strength dependence

The ionic strength dependence of the protolysis constant of water in lithium chloride media is illustrated in Figure 5.20. The solid line on the figure is derived from the use of Eq. (5.17) with log =-13.994 0.014. From use of the equation, the following ion interaction parameters are derived ... 

Ionic Strength Dependence Because the accepted stability constant data for are only from essentially two ionic strengths (there is a small difference, in terms of moles per kilogram, between 3.0 rnoll lithium and sodium perchlorate), only the standard specific ion interaction theory (i.e. Af2 = 0) can be used to calculate the stability constant at zero ionic strength. This analysis is illustrated in Figure 13.30. The stability constant determined at zero ionic strength and the associated ion interaction parameter are... 

Figure 23. Dependence of MacMillan-Mayer osmotic coefficient on concentration for lithium chloride aqueous solutions at 298 K dotted line indicates calculated and full line indicates experimental dependence on IM, the ionic strength defined in terms of MacMillan-Mayer variables (Friedman and Krishnan, 1973a).

Alkaline hydrolysis of hexafluorophosphate (PFg ) occurs without accumulation of lower fluorophosphates. The rates have been examined between 160 and 190 °C, with lithium, sodium and potassium hydroxides. At unit ionic strength (nitrates) the rates were dependent on the nature of the cation (K" < Na" " ionic strength, behaviour is more predictable and the rate expression is... 

Nitroanthranylazo (formula 5.1) has been proposed for the determination of Li [47]. The colour reaction is carried out in aqueous acetone made alkaline with KOH. The absorbance is measured at 530 nm (e= 1.2-10 ). The colour intensity depends on the medium used (water-acetone, dioxan, methanol, DMF), excess of Nitroanthranylazo, and ionic strength. In the determination of 2 pg of lithium, there is no interference of 200 pg Rb, 100 pg Mg or Ca, 50 pg Ba, Sr, or Na, The method has been applied for determination of lithium in ferrites [48]. 

Figure 5.20 Dependence of log on ionic strength in lithium chloride media. The solid line is derived from use of Eq. (5.17).

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