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1.
The viscosity of 10 (0.049, 0.205, 0.464, 0.564, 0.820, 1.105, 1.496, 2.007, 2.382, and 2.961 mol ċ kg−1) binary aqueous NaBr solutions has been measured with a capillary-flow technique. Measurements were made at pressures up to 40 MPa. The range of temperature was 288–595 K. The total uncertainty of viscosity, pressure, temperature and composition measurements were estimated to be less than 1.6%, 0.05%, 15 mK, and 0.02%, respectively. The effect of temperature, pressure, and concentration on viscosity of binary aqueous NaBr solutions were studied. The measured values of the viscosity of NaBr(aq) were compared with data, predictions and correlations reported in the literature. The temperature and pressure coefficients of viscosity of NaBr(aq) were studied as a function of concentration and temperature. The viscosity data have been interpreted in terms of the extended Jones–Dole equation for the relative viscosity (η/η0) to calculate accurately the values of viscosity A- and B-coefficients as a function of temperature. The derived values of the viscosity A- and B-coefficients were compared with the results predicted by the Falkenhagen–Dole theory of electrolyte solutions and calculated with the ionic B-coefficient data. The physical meaning parameters V and E in the absolute rate theory of the viscosity and hydrodynamic molar volume V k were calculated using the present experimental viscosity data. The TTG model has been used to compare predicted values of the viscosity of NaBr(aq) solutions with experimental values at high pressures.  相似文献   

2.
The relative viscosities were measured for LiI, NaI, KI, RbI, Bu4NBPh4, and Bu4NI in a wide range of mixtures of propionitrile and acetonitrile at 25°C to obtain Jones–Dole Bcoefficients. The Bcoefficients of these electrolytes were large and positive. The values of ionic Bcoefficients allow us to assess the behavior of ions in the solvent mixtures.  相似文献   

3.
Densities of four aqueous H3BO3 solutions (0.062, 0.155, 0.315, and 0.529 mol-kg–1) have been measured in the liquid phase with a constant volume piezometer immersed in a precisely controlled liquid thermostat. Measurements were made at temperatures between 296 and 573 K and pressures from 0.82 to 48 MPa. The total uncertainties of the density, pressure, temperature, and molality measurements were estimated to be less than 0.06%, 0.05%, 10 mK, and 0.0005 mol-kg–1, respectively. The accuracy of the method was confirmed by PVT measurements on pure water for two isobars (30 and 39 MPa) at temperatures from 313 to 573 K. The experimental and calculated (IAPWS formulation) densities for pure water show excellent agreement which is within their experimental uncertainties (average absolute deviation, AAD=0.012%;). Apparent and partial molar volumes were derived using the measured densities for solutions and pure water, and these results were extrapolated to zero concentration to yield the partial molar volumes of the electrolyte (H3BO3) at infinite dilution. The temperature, pressure, and concentration dependencies of the apparent and partial molar volumes were studied. Small pressure and concentration effects on the apparent molar volumes were found at temperatures up to 500 K. The parameters of a polynomial type of equation of state for the specific volume Vsol(P, T, m) as a function of pressure, temperature, and molality were obtained with a least-squares method using the experimental data. The root-mean-square deviation between measured and calculated values from this polynomial equation of state is ±0.2 kg-m–3 for density. Measured values of the solution densities and the apparent and partial molar volumes are compared with data reported in the literature.  相似文献   

4.
Densities of four aqueous NaNO3 solutions (0.100, 0.303, 0.580, 0.892 mol-kg–1 H2O) have been measured in the liquid phase with a constant-volume piezometer immersed in a precision liquid thermostat. Measurements were made at ten isotherms between 292 and 573 K. The range of pressure was 0.1–30 MPa. The total uncertainty of density, pressure, temperature, and concentration measurements were estimated to be less than 0.06%, 0.05%, 10 mK, and 0.014%, respectively. Values of saturated densities were determined by extrapolating experimental P- data to the vapor pressure at fixed temperature and composition. Apparent molar volumes were derived using measured values of density for the solutions and for pure water. The apparent molar volumes were extrapolated to zero concentration to yield partial molar volumes at infinite dilution. The temperature, pressure, and concentration dependence of partial and apparent molar volumes were studied. The measured values of density and apparent and partial molar volume were compared with data reported in the literature.  相似文献   

5.
Viscosity of nine aqueous Ni(NO3)2 solutions (0.050, 0.153, 0.218, 0.288, 0.608, 0.951, 1.368, 1.824, and 2.246) mol · kg−1 was measured in the temperature range from (297 to 475) K and at pressures (0.1, 10, 20, and 30) MPa. The measurements were carried out with a capillary flow technique. The total experimental uncertainty of viscosity, pressure, temperature, and composition measurements were estimated to be less than 1.6%, 0.05%, 15 mK, and 0.02%, respectively. All experimental and derived results are compared with experimental and calculated values reported in the literature. Extrapolation of the solution viscosity measurements to zero concentration (pure water values) for the given temperature and pressure are in excellent agreement (average absolute deviation, AAD = 0.13%) with the values of pure water viscosity from IAPWS formulation [J. Kestin, J.V. Sengers, B. Kamgar-Parsi, J.M.H. Levelt Sengers, J. Phys. Chem. Ref. Data 13 (1984) 175–189]. The viscosity data for the solutions as a function of concentration have been interpreted in terms of the extended Jones–Dole equation for strong electrolytes. The values of viscosity A-, B-, and D-coefficients of the extended Jones–Dole equation for the relative viscosity (η/η0) of aqueous Ni(NO3)2 solutions as a function of temperature are studied. The derived values of the viscosity A- and B-coefficients were compared with the results predicted by Falkenhagen–Dole theory (limiting law) of electrolyte solutions and the values calculated with the ionic B-coefficient data. The measured values of viscosity for the solutions were also used to calculate the effective rigid molar volumes in the extended Einstein relation for the relative viscosity (η/η0).  相似文献   

6.
17O-NMR spin-lattice relaxation timesT 1 of D2O molecules were measured at 5–85°C in D2O solutions of alkali metal halides (LiClCsCl, KBr, and KI), DCl, KOD, Ph4PCl, NaPh4B, and tetraalkylammonium bromides (Me4NBrAm4NBr) in the concentration range 0.1–1.4 mol-kg–1 TheB-coefficients of the electrolytes obtained from the concentration dependence of relaxation ratesR 1=1/T1 were divided into the ionicB-coefficients by three methods: (i) the assumption ofB (K+)=B(Cl), (ii) the assumption ofB(Ph4P+)=B(Ph4B), and (iii) the use ofB(Br) obtained from a series ofB(R4NBr). It was found that Methods (ii) and (iii) resulted in an abnormal temperature dependence of theB-coefficients of alkali metal ions and a negative values of rotational correlation times c at lower temperatures for hydroxide and halide ions. These results suggest that the methods based on the van der Waals volume are not adequate for the ionic separation of NMRB-coefficients. From the analysis using the assumption ofB(K+)=B(Cl), it was found that D3O+, OD, and Me4N+ ions are the intermediates between structure makers and breakers, and that the hydrophobicity of phenyl groups is weaker than that of alkyl groups due to the interactions between water molecules and -electrons in phenyl groups.  相似文献   

7.
The viscosity B-coefficients of mono-, di-, tri-saccharides and the derivatives (methyl glycosides) in mB = (0.5, 1.0, 2.0, and 3.0) mol · kg−1 aqueous solutions of magnesium chloride have been determined from viscosity data using the Jones–Dole equation at T = (288.15, 298.15, 308.15, and 318.15) K. The viscosity B-coefficients of transfer (ΔtB), the temperature derivatives of B-coefficients (dB/dT), pair and triplet viscometric interaction coefficients (ηAB, ηABB) have been determined. The viscosity B-coefficients data of systems studied in water have been reported earlier. The results have been interpreted in light of the solute–solute and solute–solvent interactions occurring in these systems. The comparison of results has been made with those reported in the presence of potassium chloride, ammonium sulphate, and sodium sulphate.  相似文献   

8.
The thermodynamic properties of LiNO3(aq.), NaNO3(aq.), KNO3(aq.), NH4NO3(aq.), Mg(NO3)2(aq.), Ca(NO3)2(aq.), and Ba(NO3)2(aq.) have been determined at 25°C by the hygrometric method for molalities, ranging from 0.1 mol-kg–1 to saturation. From measurements of droplet diameters of reference solutions NaCl(aq.) or LiCl(aq.), the dependence of relative humidity on solute concentration was determined. The data on the relative humidity allow deduction of water activities and the osmotic coefficients at various molalities. Osmotic coefficient data are described by Pitzer's ion interaction model. The ion interaction parameters were also determined for each of the salts studied. With these parameters, the solute activity coefficients can be predicted. These results are used to calculate the excess Gibbs energy for these aqueous electrolyte nitrates. Our present results are compared with published thermodynamic data.  相似文献   

9.
《Fluid Phase Equilibria》2005,227(1):57-70
Viscosities of nine (1.5, 3, 5, 7, 10, 15, 20, 23, and 26) mass% of aqueous Na2SO4 solutions have been measured in the liquid phase with a capillary flow technique. Measurements were made at five isobars 0.1, 10, 20, 30, and 40 MPa. The range of temperatures was from 298.15 to 573.5 K. The total uncertainty of viscosity, pressure, temperature, and concentration measurements was estimated to be less than 1.5%, 0.05%, 15 mK, and 0.015%, respectively. The reliability and accuracy of the experimental method was confirmed with measurements on pure water for four selected isobars 5, 10, 20, and 40 MPa and at temperatures between 296.7 and 573.7 K. The experimental and calculated values from 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 = 0.41%). The temperature, pressure, and concentration dependences of the relative viscosity (η/η0) where η0 is the viscosity of pure water are studied. The values of the viscosity A-, B-, and D-coefficients of the extended Jones–Dole equation for the relative viscosity (η/η0) of aqueous Na2SO4 solutions as a function of temperature are studied. The maximum of the B-coefficient near the 323 K isotherm has been found. The behavior of the concentration dependence of the relative viscosity of aqueous Na2SO4 solutions is discussed in terms of the modern theory of transport phenomena in electrolyte solutions. The derived values of the viscosity A- and B-coefficients were compared with the results predicted by Falkenhagen–Dole theory of electrolyte solutions and calculated with the ionic B-coefficient data. Different theoretical models for the viscosity of electrolyte solutions were stringently tested with new accurate measurements on aqueous Na2SO4. The quality and predictive capability of the various models was studied. The measured values of viscosity were directly compared with the data reported in the literature by other authors.  相似文献   

10.
The viscosity of dilute aqueous solutions of K3[AI(ox)3]·3H2O, K3[Fe(ox)3]·3H2O, K3[Co(ox)3]·3H2O, and K3[Cr(ox)3]·3H2O complexes, as well as K2(ox)·H2O, were measured between 15 and 35°C. Those of CoCl2, 6H2O, FeCl3, A12(SO4)3·18H2O, and CrCl3·6H2O were measured at 25°C. These data were analyzed by the Jones–Dole equation. The ionic B coefficients of the above complex anions were discussed in terms of ion–solvent interactions and the overall change in B associated with complex formation.  相似文献   

11.
Summary.  Density and viscosity of NaNO3 and KNO3 in aqueous and in H2O-urea solutions were determined as a function of electrolyte concentrations at 308, 313, 318, 323, and 328 K, respectively. The apparent molal volume (φ v ) of the electrolytes were found to be linear functions of the square root of the solute molality (b). The φ v and data were fitted to the Masson equation [1] by the least square method to obtain the apparent molar volume at infinite dilution (φ v ^), which is practically equal to the partial molar volume . The viscosity coefficients A and B were calculated on the basis of the viscosity of the solutions and the solvent concerned using the JonesDole [2] equation. The activation parameters for viscous flow (ΔG , ΔS , and ΔH ) were calculated according to Eyring [3]. The values of for the two systems were also calculated from B-coefficient data. The results were found to be of opposite nature in the two electrolyte systems. Where sodium nitrate showed structure making behaviour both in aqueous and in H2O-urea solutions, KNO3 showed structure breaking behaviour in aqueous solutions and structure making behaviour in 5 molal H2O-urea solutions in the studied temperature range. The behaviour of these two electrolytes in aqueous binary and in aqueous-urea ternary systems are discussed in terms of charge, size, and hydrogen bonding effects. Corresponding author. E-mail: chemistry_ru@yahoo.com Received January 24, 2002; accepted (revised) April 5, 2002  相似文献   

12.
Apparent molar volumes, viscosity B-coefficients, and apparent molar isentropic compressibilities of glycine, L-alanine, L-valine and L-leucine in 0.062, 0.125 and 0.256 mol kg?1 aqueous tetra-butyl ammonium bromide (TBAB) solution have been determined at 298.15 K from their experimental density, flow time and sound speed measurements, respectively. The standard partial molar volumes and compressibilities are used to calculate the corresponding volume of transfer at infinite dilution, from water to aqueous TBAB solutions. The linear correlation of partial molar volumes for a homologous series of amino acids has been utilised to calculate the contribution of charged end groups and other alkyl chains of the amino acids to partial molar volumes. The hydration numbers of amino acids have also been determined. Viscosity B-coefficients have been calculated using the Jones–Dole equation. The values of the charged end groups contribution to the viscosity B-coefficients of the amino acids are calculated.  相似文献   

13.
The values of the second dissociation constant, pK2, and related thermodynamic quantities of 4-(N-morpholino)butanesulfonic acid (MOBS) and N-tris(hydroxymethyl)-4-aminobutanesulfonic acid (TABS) have already been reported over the temperature range 5–55°C including 37{°}C. This paper reports the pH values of twelve equimolal buffer solutions at designated pH (s) with the following compositions: (a) mixtures of MOBS (0.05 mol-kg–1) + NaMOBS (0.05 mol-kg–1); (b) MOBS (0.08 mol-kg–1) + NaMOBS (0.08 mol-kg–1); (c) MOBS (0.08 mol-kg–1) + NaMOBS (0.08 mol-kg–1) + NaCl (0.08 mol-kg–1); (d) TABS (0.05 mol-kg–1) + NaTABS (0.05 mol-kg–1); and (e) TABS (0.08 mol-kg–1) + NaTABS (0.08 mol-kg–1); and (f) TABS (0.08 mol-kg–1) + NaTABS (0.08 mol-kg–1) + NaCl (0.08 mol-kg–1). Two buffer solutions have ionic strengths I= 0.05 mol-kg–1, another two have I=0.08 mol-kg–1, and the remaining two buffer solutions have I= 0.16 mol-kg–1, which is close to that of the clinical fluids (blood serum). These buffers have been recommended as a useful pH standard for the measurements of physiological solutions. Conventional pH values of all six buffer solutions from 5–55°C, as well as those obtained from the liquid junction potential correction at 25 and 37{°}C have been calculated. The flowing-junction calomel cell has been utilized to measure Ej, the liquid junction potential.  相似文献   

14.
Using the ion-interaction or virial coefficient approach developed by Pitzer, the pressure dependencies of the osmotic and activity coefficients for K2SO4(aq) up to 225°C and 0.65 mol-kg–1 have been calculated from recent literature data on the apparent molar volumes of K2SO4(aq). These pressure dependencies were combined with the osmotic and activity coefficients at 1 bar or P sat, obtained from the model of Holmes and Mesmer to yield a comprehensive set of thermodynamic properties of K2SO4(aq) at temperatures from 25 to 225°C, pressures 100, 200, and 300 bars, and molalities to 0.65 mol-kg–1.On leave from the  相似文献   

15.
A flow microcalorimeter/densimeter system has been commissioned to measure heat capacities and densities of solutions containing radioactive species as a function of temperature. Measurements were made for NaTcO4(aq) at six temperatures (189.15 K to 373.15 K for the heat capacities, 287.43 K to 396.67 K for the densities) over the molality range 0.01 to 0.29 mol-kg–1. Measurements for NaReO4(aq) (NaReO4 is a common nonradioactive analogue for NaTcO4) were made under similar conditions, but for eight temperatures and a more extensive range of molalities, 0.05 to 0.65 mol-kg–1. Heat capacities of NaCl(aq) reference solutions were also measured from 293.15 K to 398.15 K.The heat capacity and density data are analysed using Pitzer's ioninteraction model. Equations for the apparent molar heat capacities and volumes are reported. Values of the NaReO4(aq) partial molar heat capacities are compared to literature values based on integral heats of solution. The agreement between the two sets of NaReO4 results is good below 330 K, but only fair at the higher temperatures. Values of the partial molar volumes have also been derived. Using literature values and the results of our experiments, it is calculated that the disproportionation of hydrated TcO2(s) to form TcO 4 (aq) and Tc(cr) occurs more readily at high temperatures. The uncertainties introduced by using thermodynamic values for ReO 4 (aq), in the absence of values for TcO 4 (aq), are discussed.  相似文献   

16.
The Jones–Dole viscosity B-coefficients for various mono-, di-, and tri-saccharides in water and in (0.5, 1.0, 2.0, and 3.0) mol · kg?1 aqueous solutions of sodium acetate have been determined at different temperatures, T = (288.15, 298.15, 308.15, and 318.15) K from viscosity data. Densities used to determine viscosities have been reported earlier. The viscosity B-coefficients of transfer, ΔtB, has been estimated for the transfer of saccharides from water to aqueous sodium acetate solutions. The positive ΔtB values were obtained in all cases and their magnitudes increase with the increase in concentration of sodium acetate. Pair, ηAB and higher order, ηABB viscometric interaction coefficients (using McMillan–Mayer theory), and dB/dT coefficients have also been determined. Activation Gibbs free energies and other related thermodynamic activation parameters of viscous flow have been determined using Feakin’s transition-state theory. These parameters have been discussed in terms of solute–solute and solute–solvent interactions occurring in these solutions.  相似文献   

17.
The values of density (ρ), viscosity (η) and speed of sound (u) have been measured for binary liquid mixtures of γ-butyrolactone (GBL), δ-valerolactone (DVL), and ε-caprolactone (ECL) with N-methylacetamide (NMA) over the whole composition range at T = (303.15 to 318.15) K and atmospheric pressure. From these data, excess molar volume (VE), deviation in viscosity (Δη), and deviation in isentropic compressibility (Δκs), are calculated. The results are fitted to a Redlich–Kister type polynomial equation to derive binary coefficients and standard deviations.  相似文献   

18.
The available literature data on the osmotic coefficient of ZnSO4(aq) at 25°C in the molality range from 0.1 to 4.3 mol-kg–1 and new experimental data from 1.2 to 2.9 mol-kg–1, at the same temperature, are presented. Selected values of the osmotic coefficient from all the data are analyzed using the Clegg-Pitzer-Brimblecombe model, the extended Pitzer model, and a semiempirical equation comprising a power series in molality added to the Debye-Hückel limiting law. The extended Pitzer equation and the Clegg-Pitzer-Brimblecombe equations give the best results in fitting the osmotic coefficient data. All three models are used to calculate ZnSO4 activity coefficients at 25°C in dilute solutions (<0.1 mol-kg–1) for comparison with published values.  相似文献   

19.
Transference numbers of HCl(aq) solutions at 25°C, from 0.01 to 13.6 mol-kg–1(m) have been obtained by measuring the emf of cells with transference using hydrogen gas/platinum electrodes. Good agreement is obtained at concentrations up to 1 m with all previous data, and our results strongly corroborate those of King and Spiro over the 2–8m concentration range. The transference numbers of the hydronium ion fit the empirical equation, H HCl = 0.821 + 0.0457m 1/2 – 2.476×10–2m – 1.90×10–4 m 2 – 1.45×10–5 m 3 the maximum deviation in T H HCl being 0.003.  相似文献   

20.
Ali  A.  Shahjahan  Ansari  N. H. 《Russian Chemical Bulletin》2010,59(10):1999-2004
The densities and viscosities of aqueous solution of cetyltrimethylammonium bromide (0.01 mol kg−1) (CTAB) and solutions of CTAB containing amino acids, viz., glycine, l-serine, and l-valine (0.01–0.05 mol kg−1), were determined in the temperature range 298.15—313.15 K. Apparent molar volumes of the amino acids were calculated from the density and viscosity values. The calculated apparent molar volumes were used to calculate standard partial molar volumes (-V 20) and standard partial molar volumes of transfer of amino acids from water to an aqueous solution of CTAB. The viscosity values were used for the calculation of the viscosity coefficients A and B in the Jones—Dole equation. The linear dependences of -V 20 and B on the number of carbon atoms in the alkyl chains of the amino acids were found. The results obtained were used in analysis of hydrophilic-hydrophilic, hydrophilic-hydrophobic, and hydrophobic-hydrophobic interactions that occur during dissolution of amino acids in an aqueous solution of CTAB.  相似文献   

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