SOME TRANSPORT-PROPERTIES OF LIQUIDS FROM MOLTEN ELECTROLYTES TO WATER

It is found that the parameters of equations recently proposed for the fluidity and the equivalent electrical conductance of highly ionic nitrate-water systems reflect sensitively the cation's hydrating power. The relative water structure breaking power of a cation in very ionic solutions where the water is the solute is comparable to that in dilute aqueous solutions In these equations, the concentration is expressed by the ordinary mole fraction. But, if it is replaced by the mole fraction on an ionized basis, a simple equation appears to be applicable over the dilute aqueous solution concentration range in the case of the fluidity. A derivation of the Batschinski equation from the Eyring equation for the viscosity is also proposed on the basis of the fluctuating hole concept and the free volume concept. From this point of view, in water, over the temperature range 40-100°C, the fluctuating holes would represent about all the free volume as defined in the Batschinski equation or an important part of it. On the contrary, in an anhydrous molten nitrate system the fluctuating holes would represent only a small part of the free volume. Besides, the correlation between the apparent molar volume of water and the transport parameters confirms the usefulness of structural concepts in the study of transport phenomena. © 1990 American Chemical Society.