Volumetric properties of the binary system (NaClO3 + H2O) and the ternary system (NaClO3 + NaCl + H2O) at temperatures from 283.15 to 363.15 K and ambient pressure

Volumetric properties for the ionic membrane mixture electrolytes in chlor-alkali industry were investigated for the first time. The densities for the binary system (NaClO3 + H2O) with molality of NaClO3 up to 9.2311 mol·kg−1 and the ternary system (NaClO3 + NaCl + H2O) with molality of NaClO3 from 0.8 to 3.0 mol·kg−1 and NaCl from 0.65 to 2.3 mol·kg−1 over the temperature range from (283.15 to 363.15) K at intervals of 5 K and ambient pressure were determined experimentally using an accurate digital vibrating - tube densimeter. The derived properties of apparent molar volume (Vϕ) for the two systems were obtained based on the experimental data. On the basis of volumetric property data on the binary and ternary systems, the Pitzer single-salt parameters (β(0)ν MX, β(1)ν MX and C(0)ν MX, MX = NaClO3) and mixing ion-interaction parameters (θv Cl,ClO3, ψv Na,Cl,ClO3) were parameterized according to Pitzer ion-interaction theory of single salt electrolyte and mixture electrolytes, and their temperature-dependence equations [FMX (i, p, T) = ai,1 + ai,2ln(T/298.15) + ai,3(T-298.15) + ai,4/(620-T) + ai,5(T-227), i = 1 to 3 for β(0)ν MX, β(1)ν MX and C(0)ν MX and i = 1 and 2 for θv Cl,ClO3, ψv Na,Cl,ClO3, respectively] as well as their relative temperature correlation coefficients ai for those parameters were also obtained for the first time by the least square fitting. Vice versa, the volumetric properties of electrolytes for the two systems at any temperatures between 283.15 and 363.15 K can be quantitatively acquired based on the parameterized model of electrolytes.