Transport measurements in aqueous sodium sulfate. Evidence for like-ion pairs in concentrated solutions
Precise self-diffusion and conductance data are reported for aqueous solutions of sodium sulfate at 25°C in the general concentration range 0.1 mol dm-3 to saturation. These data in conjunction with mutual diffusion, transference, and activity coefficient data enable the calculation of velocity correlation coefficients, fab, and closely related 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.