Viscosity of Aqueous Electrolyte Solutions at High Temperatures and High Pressures. Viscosity B-coefficient. Sodium Iodide

Abstract

The viscosity of seven (0.062, 0.166, 0.456, 0.552, 1.754, 3.062, and 4.700) mol·kg-1 binary aqueous NaI solutions has been measured with a capillary-flow technique. Measurements were performed at pressures up to 30 MPa. The range of temperature was from (298 to 575) K. The total uncertainty of viscosity, pressure, temperature, and composition measurements was estimated to be less than 1.6 %, 0.05 %, 15 mK, and 0.015 %, respectively. The effect of temperature, pressure, and concentration on viscosity of binary aqueous NaI solutions was studied. The measured values of the viscosity of NaI(aq) were compared with data, predictions, and correlations reported in the literature. The viscosity data have been analyzed and interpreted in terms of the extended Jones−Dole equation for the relative viscosity (η/η0) of strong electrolyte solutions to accurately calculate the values of the viscosity A- and B-coefficients as a function of temperature. The derived values of the viscosity A- and B-coefficients were compar...