Ionic Strength Estimation and Development Of Equation For Estimation Of Ion Atmosphere Thickness In Aqueous Solutions By Electrical Conductivity For Some Electrolytes

Abstract

The relation between electrical conductivity (cond) and ionic strength (I) in aqueous solutions for some electrolytes (NaCI,NaNO3,Na2CO3,NaSO4,K2SO4,CuSO4,MgSO4.7H2O), has been studied at 25 ◦C, at various concentrations (0.1- 10 molar). 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 the calculated values from the general law I=½∑Zi2Ci. The electrical conductivity is increased with increasing of Ionic strength as in the following order :Na2SO4 > K2SO4 > MgSO 4 > CuSO4 And Na2SO4 > Na2CO3 > NaCI > NaNO3