Charging, symmetrical

T. Kennedy. Debye-Hueckel theory for charge symmetric Coulomb systems. Commun Math Phys 92 269-294, 1983. 

A long thin cylindrical tube of radius a = 5 X 10 m and length L = 0.1 m is closed at both ends by electrodes, across which a voltage drop A(f> = 10 V is applied. The tube contains an ideal dilute aqueous solution of a fully dissociated doubly charged symmetrical binary salt (z = 2) at a concentration Cg = 1 mol m . The tube wall has a fixed surface potential = 1.43x10 V. The temperature T = 25°C, the permittivity e = 7x... 

The structural picture of molten salts emerging from the data dealt with in Sect. 3.2, consists of intertwining quasi-lattices of cation sites and anion sites. In charge-symmetrical salts 1 1 (e.g. NaCl) and 2 2 (e.g. CaO) a majority of the sites are occupied by the itms, with some of them empty. However, charge-unsymmetrical salts, namely 1 2 (e.g. CaFa), 1 3 (e.g. LaCls), 2 1 (e.g. LiaCOa), etc., have a substantial number of unoccupied sites, whether of sizes commensurate with those of the ions or collapsed to smaller sizes. It is expedient to deal with charge-symmetrical molten salts separately from the charge-unsymmetrical ones. 

Tb/K (lower row), of charge-symmetrical salts, from [1] and values in... 

Fairly constant values of the reduced vapor pressures P corresponding to deviations of <2 % in the enthalpy of vaporization, resulted at corresponding temperatures of r= 1.30 I m and 1.55 T. Fairly constant values of the reduced surface tension of uni-univalent salts also resulted at T= 1.00 and 1.10 T. Agreement with experimental data was obtained for charge-symmetrical molten salts except for the lithium halides, and for charge-unsymmetrical salts only for the alkaline earth metal fluorides, whereas for other salts of this class some degree of covalent bonding was supposed to account for the deviations. 

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