Some aspects of the present status of the thermodynamics of electrolytic solutions

We have surveyed in a brief manner some phases of the experimental thermodynamics of electrolytic solutions. A more complete review would be very voluminous, and would include a number of other topics. As examples, the investigations of electrolytes of higher valences types such as cadmium chloride (34), and iodide (8), barium chloride (85), and zinc sulphate (11) (55). It would also include a discussion of the important work of Gibson (14) who has measured the compressions of a number of aqueous salt solutions up to 1000 bars. Nor have we discussed the recent interpretations of the behaviors of strong electrolytes in solutions at higher concentrations where the theory of Debye and Hückel is no longer adequate without considerable extension. This complicated subject has been investigated most comprehensively by Scatchard (78) (80) and its discussion would lead beyond the intended limits of this survey. We trust that this sketch of our results will help somewhat to give a correct impression of the extent and direction of this part of solution chemistry. The development of method in these studies of equilibria has reached the stage where a really reliable and accurate body of evidence is becoming available. This is very important because accurate data will be required not only as criteria and as a guide to the approximate statistical and quantum mechanical interpretations of equilibrium constants, entropies, activation energies, and reaction velocity constants where ions are involved, but also in the further clarification of the state of ions in solution.     

Longitudinal stability of latent means and individual differences: A unified approach

We examined the stability of responses to a multi‐item self‐esteem scale collected on five occasions over an 8‐year period. A wide variety of approaches were critically examined that considered the stability of means, individual differences (i.e., test‐retest correlations), and factor structures using traditional approaches (e.g., ANOVA and correlations) and structural equation models. Structural equation models based on multiple indicators provided a unified analytic approach for evaluating different aspects of stability and offered important advantages over traditional approaches. We describe a hierarchy of invariances and the nature of interpretations that are justified by different patterns of factor structure invariance associated with each level. We conclude that the assumptions underlying the typical repeated‐measures ANOVA approach to testing mean differences in longitudinal data are far more restrictive, less easily tested, and less likely to be met than those in the structural equation modeling approach advocated here, and that the use of ANOVA for this purpose requires a huge leap of faith that can rarely be justified on logical or empirical grounds.