Latimer, ionic entropies

Historically, the usefulness of ionic entropies first was emphasized by Latimer and Buffington (19), who established the convention of setting the standard entropy of hydrogen ion equal to zero that is. 

Based on Latimer s scale of conventional ionic entropies. Units are cal K mol... 

As in the case of heats and heat capacities, ionic entropies have been examined more extensively in methanol and methanol-water mixtures than in other solvents. The earliest study was that of Latimer and Slansky who report entropies for NaCl, KCI, KBr, and HCl in water-methanol mixture from 0 to 100% methanol. Jakuszewski and Taniewska-Osinska " have determined the entropies of numerous halide salts and HCl at 25 C, and more recently Franks and Reid, using data from the literature, have calculated standard ionic entropies for several species in water-methanol mixtures covering the whole concentration range. It should be observed that these authors chose the mol fraction standard state for the solute in solution and ideal ionic gas as the standard state for the pure solute instead of the conventional hypothetical one molal solution and pure solid at OK. The former standard states are convenient when comparing entropies of solvation for the various species. Ionic entropies in methanol are considerably more negative than in water. 

Charles (1954) has compared the entropy of ethylenediamine-tetraacetate (EDTA) complex formation for several elements, including zinc, and finds the entropy change to be a linear function of the partial molal entropy of the complexed metal. In Fig. 10, the entropy changes in the formation of ammonia (Williams, 1954), ethylenediamiue (En) (Davies et al., 1954), and EDTA (Charles, 1954) complexes of Zn, Cu, and Cd are plotted as a reciprocal of the ionic radius minus a term containing the molecular weight (Powell and Latimer, 1951), as a measure of the partial molal entropy of the cations. The AS° values plotted are for the reaction ... 

---