The thermal conductivity of three (0.239, 0.499, and 0.782 mol·kg −1 ) and the viscosity of four (0.0658, 0.2055, 0.3050, and 0.4070 mol·kg −1 ) binary aqueous K 2 SO 4 solutions have been measured with coaxial-cylinder (steady-state) and capillary-flow techniques, respectively. Measurements were made at pressures up to 30 MPa, and the range of temperature was 298-575 K. The total uncertainties of the thermal conductivity, viscosity, pressure, temperature, and composition measurements were estimated to be less than 2%, 1.6%, 0.05%, 30 mK, and 0.02%, respectively. The measured values of the thermal conductivity and viscosity of K 2 SO 4 (aq) were compared with data and correlations reported in the literature. The reliability and accuracy of the experimental method was confirmed with measurements on pure water with well known (IAPWS standards) thermal conductivity and viscosity values (deviations, AAD, within 0.31 % and 0.52 %, respectively). The values of the viscosity A-, B-, and D-coefficients of the extended Jones-Dole equation for the relative viscosity (η/η 0 ) of aqueous K 2 SO 4 solutions as a function of temperature were studied. The maximum of the Bcoefficient near 340 K has been found. The derived values of the viscosity A-and B-coefficients were compared with results predicted by the Falkenhagen-Dole theory of electrolyte solutions and calculated with the ionic B-coefficient data. The behavior of the concentration dependence of the relative viscosity of aqueous K 2 SO 4 solutions is discussed in terms of the modern theory of transport phenomena in electrolyte solutions. 5930195-928X/05/0500-0593/0

Viscosities of four aqueous Li 2 SO 4 solutions [(0.10, 0.28, 0.56, and 0.885) mol‚kg -1 ] have been measured in the liquid phase with a capillary flow technique. Measurements were made at four isobars [(0.1, 10, 20, and 30) MPa]. The range of temperatures was from (298 to 575) K. The total uncertainties of viscosity, pressure, temperature, and concentration measurements were estimated to be less than 1.5%, 0.05%, 10 mK, and 0.014%, respectively. The reliability and accuracy of the experimental method were confirmed with measurements on pure water for three isobars [(10, 20, and 30) MPa] and at temperatures between (298 and 575) K. The experimental and calculated values from the IAPWS (International Association for the Properties of Water and Steam) formulation for the viscosity of pure water show excellent agreement within their experimental uncertainty (AAD is about 0.51%). A correlation equation for viscosity was obtained as a function of temperature, pressure, and composition by a least-squares method from the experimental data. The AAD between measured and calculated values from this correlation equation for the viscosity was 0.7% for pure water and 0.74% for the solutions. The measured values of viscosity at atmospheric pressure were compared with the data reported in the literature by other authors.

Dynamic viscosities of seven (0.3207, 0.6771, 1.5235, 2.0310, 2.6118, 3.2810, and 4.0628) mol‚kg -1 and kinematic viscosities of two (4.9861 and 6.0941) mol‚kg -1 aqueous Ca(NO 3 ) 2 solutions have been measured in the liquid phase with a capillary flow technique. Measurements were made at six isobars (0.1, 5, 10, 20, 30, and 40) MPa. The range of temperatures was from (298 to 573) K. The total uncertainty of viscosity, pressure, temperature, and concentration measurements were estimated to be less than 1.5%, 0.05%, 15 mK, and 0.014%, respectively. The reliability and accuracy of the experimental method was confirmed with measurements on pure water for five selected isobars (1, 10, 20, 40, and 50) MPa and at temperatures between (294.5 and 597.6) K. The experimental and calculated values from International Association for the Properties of Water and Steam formulation for the viscosity of pure water show excellent agreement within their experimental uncertainty (average absolute deviation, AAD ) 0.27%). A correlation equation for viscosity of solutions was obtained as a function of temperature and pressure for each measured composition by a least-squares method from the experimental data. The AAD between measured and calculated values from this correlation equation for the viscosity was 0.6 %. The measured values of viscosity at atmospheric pressure were directly compared with the data reported in the literature by other authors.

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The thermal conductivity of four binary aqueous NaBr solutions of (10, 20, 30, and 38) mass %, three binary aqueous KBr solutions of (10, 20, and 30) mass %, and three ternary aqueous NaBr + KBr solutions of (10NaBr + 5KBr, 10NaBr + 10KBr, and 10NaBr + 20KBr) mass % have been measured with a concentric-cylinder (steady-state) technique. Measurements were made near the saturation curve of (0.1 to 2) MPa and at two isobars of (10 and 40) MPa. The range of temperature was (294 to 577) K. The total uncertainty in the thermal conductivity, pressure, temperature, and composition measurements was estimated to be less than 2%, 0.05%, 30 mK, and 0.02%, respectively. The temperature, pressure, and concentration dependence of the thermal conductivity of binary and ternary solutions were studied. The measured values of thermal conductivity were compared with data and correlations reported in the literature. The reliability and accuracy of the experimental method was confirmed with measurements on pure water with well-known thermal conductivity values. The experimental and calculated values of thermal conductivity for pure water from the IAPWS formulation show excellent agreement within their experimental uncertainties (AAD within 0.51%) in the temperature range from (290 to 575) K and at pressures up to 40 MPa. Correlation equations for the thermal conductivity of the binary solutions studied were obtained as a function of temperature, pressure, and composition by a least-squares method from the experimental data. The AAD between measured and calculated values from this correlation for the thermal conductivity was 1.5%.

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Thermal conductivity of five aqueous Sr(NO3)2 solutions of molality (0.249, 0.525, 1.181, 2.025, and 3.150) mol·kg-1 and four aqueous LiNO3 solutions of molality (1.0, 1.7, 2.8, and 3.9) mol·kg-1 have been measured with a concentric-cylinder (steady) technique. Measurements were made at five isobars (0.1, 10, 20, 30, and 40) MPa for H2O+Sr(NO3)2 and at four isobars (0.1, 10, 20, and 30) MPa for H2O+LiNO3 solutions. The range of temperature was (293.15 to 591.06) K. The total uncertainty of thermal conductivity, pressure, temperature, and molality measurements were estimated to be less than 2%, 0.05%, 30 mK, and 0.02%, respectively. The measured values of thermal conductivity were compared with data and correlations reported in the literature. The reliability and accuracy of the experimental method was confirmed with measurements on pure water, toluene, and H2O + NaCl with well-known thermal conductivity values. The experimental and calculated values of thermal conductivity for pure water from IAPWS formulation show excellent agreement within their experimental uncertainties (AAD within 0.44%) in the temperature range from (308.4 to 704.2) K and at pressures up to 60 MPa. Correlation equations for thermal conductivity of the solutions studied were obtained as a function of temperature, pressure, and composition by a least-squares method from the experimental data. The AAD between measured and calculated values from this correlation equation for the thermal conductivity was (0.5 to 0.7) %.