IMPROVEMENT IN THE MEASUREMENT OF DIFFUSION-COEFFICIENTS IN A RESTRICTED DIFFUSION CELL - CASE OF BINARY ELECTROLYTES

The paper deals with measuring the diffusion coefficient of an electro lyte by the restricted diffusion method. A new design for the cell was proposed together with a more accurate solution of Fick's law for the boundary conditions considered: in particular, the initial concentrat ion gradient between the dilute and the more concentrated solutions wa s taken into account and the numerical solution obtained described the total transient phenomenon. The new arrangement has been tested using the conductimetric technique, for the case of binary diffusion of pot assium chloride and sulfuric acid at 25 degrees C. (C) 1997 Elsevier S cience S.A.