MEASUREMENT AND SIGNIFICANCE OF TRANSPORT NUMBER IN FUSED SALTS

The concept of transport numbers in fused salts is discussed in the light of the inapplicability of the usual definition applied to electrolytic solutions. The lack of a solvent reference frame, with respect to which the mobilities of the ions are normally compared, necessitates employment of a microscopic definition, if the conductance of a molten electrolyte is to be divided into a sum of meaningful ionic conductances. Thus, the reference frame selected here consists of the large bulk of ions not involved in the conductivity process at any given instant, i.e., those ions which lack the necessary energy of activation for migration. The transport numbers are therefore the fractions of current carried by the migrating ions during electrolysis as measured with respect to this frame.</p

TRANSFERENCE NUMBERS AND ION ASSOCIATION IN PURE FUSED ALKALINE EARTH CHLORIDES

The transference number of the chloride ion was determined in pure fused MgCl/sub 2/, CaCl/sub 2/, SrCl/sub 2/, and BaCl/sub 2/ utili zing radioactive chloride ions in a porous quartz membrane cell. On the basis of a two-step dissociation for these salts, MCl/sub 2/ in equilibrium MCl/sup +/ + Cl/sup -/ in equilibrium Ml/sup +/ + 2Cl/sup -/, the ext ent of the second dissociation was qualitatively predicted from a consideration of the relative mobilities of the ions. (auth

The Way and the Word: Science and Medicine in Early China and Greece, by Geoffrey Lloyd and Nathan Sivin, New Haven and London: Yale University Press, 2002,”

While it is evident that a metal ion in aqueous solution interacts electrostatically with water molecules and the anions present in the solution, it is equally apparent that often the metal ion chemically combines with varying numbers of ions or molecules to form complex species. This tendency towards coordination complexing is observed most often with the transition metals and results in a series of complex species MA with n being the number of ligand molecules A which are cpmplexed to the metal ion M and is equal to 1, 2, ..., N-1, N, where N is the maximum observed coordination number but not necessarily identical with Werner vs coordination number for the metal ion. A portion of the work abstracted in this paper was concerned with devising a simple method for the determination of kn2 where kn1 = (MAn)/(MAn-1)(A)