Ionic strength estimation from electric conductivity and studying of effect dielectric constant on electric conductivity for Sodium sulfate


The relation between electrical conductivity (cond) and ionic strength (I) in aqueous solutions for,Na2SO4, has been studied at 25 ◦C, at various concentrations (0.01- 1M ) and various dielectric constant. The ionic strength was calculated from the measurements of the electrical conductivity. The Factors (F) of these electrolytes have been obtained to certain limits of the concentration from equation ( I = F . Cond) .By this method ,we can calculate the ionic strength directly by measuring the conductivity for any unknown sample. This relationship gives more accurate results with a simple and easy method. The ionic strength values obtained from the suggested mathematical relationship was substituted in Debye-Huckle equation to determine activity coefficient (γ±). The results were similar if compared with those calculated from the general law I=½∑Zi2Ci. The electrical conductivity is increased with increasing of ionic strength and dielectric constant :