Convenient Single-ion Activities.

The nature of single-ion activity coefficients calculated from potentiometric measurements on cells with liquid junctions

“…Inspection of the remaining eight reveals that all deviate likewise from the Debye-Hückel equation in the calibration range, some even more spectacularly than shown in figure 4. No comment is given in either [23] or [60] on this discrepancy or on the earlier data of Bagg and Rechnitz [63] or Hurlen [49]. It appears therefore that their data for KCl solutions are biased and cannot serve the purpose of testing.…”

“…The deviations in figure 9 are even worse (0.09 maximum) and also tend to increase with increasing molality. However, considering the dissimilar manners in which the two series of data deviate from the respective curves at higher molalities it appears justified to conclude that the deviations arise from experimental inaccuracies rather than [49] plotted versus NaCl molality and compared with the datapoints from that work. from any flaw in the c Na (c ± , t i ) function under test or the glass membrane non-ideality (in the sense of equation (55)).…”

“…Although more extensive data are presented in recent papers of Schneider et al [60] and Lladosa et al [23], we start with the work of Hurlen [49], which is the more straightforward in interpretation.…”

“…There is yet another way, which is sometimes used, especially in the case of cells with dissimilar electrodes (e.g., [49,50,25]). It runs as follows.…”

“…The respective outputs are shown in figures 6 and 7, along with the data from [69] and [49]. Additionally, the c Cl (c ± , t i ) function for the KCl.…”