Ion association and the analysis of precise conductimetric data

Conductance Study of Ion Pairing of Alkali Metal Tetrafluoroborates and Hexafluorophosphates in Acetonitrile

“…Similar results ?Reanalysis of data from ref. 10. have been found by other workers using this method of data treatment in different solvents (16,17,21). Table 1 lists the results of the leastsquares fitting.…”

“…These include assigning a value of the Bjerrum distance (18,19) or some other value to d in the J, and f, terms and performing a three-parameter fit for A,, K,, and J,, or assigning a value of d in J,, J,, and f, and performing a two-parameter fit (20). Perhaps a more reasonable approach is to perform several two-parameter analyses of the data using a series of values for d (16,21). The distance parameter which yields a minimum standard deviation of fit, oA, to the conductance data along with the corresponding A, and KA values is chosen as the optimized parameter.…”

Chemical speciation of environmentally significant metals with inorganic ligands Part 2: The Cu2+-OH-, Cl-, CO32-, SO42-, and PO43- systems (IUPAC Technical Report)

“…Unfortunately, the insights produced by these comprehensive and sophisticated investigations have been largely ignored in subsequent publications reporting stability constant or related data. It is inappropriate here to go into the details of the investigations by Pitzer [72PIa], Prue et al [55BPb,71HPa], and others on this topic, but a summary of 4 Recalculated value to 25 °C assuming ∆ r H = 7.3 kJ mol -1 (Table A2-11). 5 High field conductivity 6 Data also reported at other temperatures.…”

“…After a detailed analysis, he noted that, "variations in theoretical treatment may substantially change [K°, and that] it may become desirable to adopt reasonable but arbitrary conventions [present authors' italics] which would make K values unambiguous" [but, note, not more accurate]. Similarly, Prue et al [71HPa] and others [81YYa, 2005BES], analyzing reliable high-accuracy conductivity data, have shown that K°is significantly dependent both on the activity coefficient expression and the conductivity expression adopted. These studies have shown in detail why it is not possible to unambiguously fix the value of K°with the sort of accuracy which would normally be expected from high-quality data for such an apparently uncomplicated system.…”

Evaluation of the solubility of electrolytes from conductivity measurements

“…6) for solvent media having a dielectric constant smaller than 20, as well as the case of (2-2) sulfates in water (ref. 7), show that the Bjerrum distance is a good choice for the minimum distance of closest approach of free ions, even when the interionic electrostatic interactions may be rather large.…”