Diffusion in dilute aqueous acetic acid solutions at 25�C

Abstract

A conductimetric technique has been used to measure diffusion coefficients for aqueous solutions of acetic acid at concentrations from 0.002 to 0.02 mol-dm−3 at 25°C. The acetic acid component diffuses more rapidly at lower concentrations where a higher proportion of the slower acid molecules are converted by dissociation to acetate ions and highly mobile hydrogen ions. The observed concentration dependence of the diffusion coefficient verifies the limiting law for weak electrolyte diffusion. A new type of conductimetric diffusion cell with several practical advantages over earlier designs is described together with an improved procedure for the conductimetric determination of accurate diffusion coefficients for weak electrolyte systems.