Transference coefficients and transferen

A new procedure is proposed for the determination of transference numbers from emf measurements, particularly applied to molten fluorides by utilizing literature data. This study illustrates that the emf measurements reported for a cell incorporating NaF and AlF3 yield transference numbers that seem physically implausible. Notably, the transference number for Na+, identified as t+ in pure NaF, lacks thermodynamic significance in the absence of pressure gradients. The analysis of data for the system NaF-AlF3-Al2O3(sat) delineates the motion of a single ion in relation to all others, and variations in t+ are examined across different frames of reference. Furthermore, it highlights inconsistencies found in some experimental results and emphasizes the thermodynamic implications of these findings. To enhance the understanding of these dynamics, new experimental approaches are recommended. The research addresses the critical requirement for reliable data spanning a wide range of concentrations, which is vital for accurate calculations of cell potentials and local heating at the electrodes.