TRANSPORT MEASUREMENTS IN AQUEOUS SODIUM-SULFATE - EVIDENCE FOR LIKE-ION PAIRS IN CONCENTRATED-SOLUTIONS

Precise self-diffusion and conductance data are reported for aqueous s olutions of sodium sulfate at 25-degrees-C in the general concentratio n range 0.1 mol dm-3 to saturation. These data in conjunction with mut ual diffusion, transference, and activity coefficient data enable the calculation of velocity correlation coefficients, f(ab), and closely r elated transport coefficients, which may serve as sensitive probes for ion configurations in solution. Evidence is found for like-ion pairs at concentrations above 0.1 mol dm-3.