Studies on Aqueous Solutions of Sodium Poly-L-glutamates. Determinations of Mean Activity Coefficients, Osmotic Coefficient, Transference Number, and Partial Molal Volume

1969 ◽  
Vol 2 (4) ◽  
pp. 401-407 ◽  
Author(s):  
Norio Ise ◽  
Tsuneo Okubo
Keyword(s):  
Aqueous Solutions ◽  
Activity Coefficients ◽  
Osmotic Coefficient ◽  
Transference Number ◽  
Partial Molal Volume ◽  
Molal Volume ◽  
Mean Activity Coefficients

Thermodynamics of the HSO4– Formation in Aqueous Solutions up to 473 K and 975 bar

1993 ◽  
Vol 48 (11) ◽  
pp. 1073-1080
Author(s):  
B. A. Bilal ◽  
E. Müller
Keyword(s):  
Aqueous Solutions ◽  
Equilibrium Constant ◽  
Formation Constant ◽  
Saturation Pressure ◽  
Partial Molal Volume ◽  
Molal Volume ◽  
Volume Entropy

Abstract The equilibrium constant, partial molal volume, entropy and enthalpy of the formation of HSO4- ion in aqueous solutions have been determined up to 473 K and 975 bar at the ionic strengths 1 = 0 as well as in NaCl solutions having I = 1, 0.5 and 0.1 mol kg-1 At 473 K, for instance, the thermodynamic formation constant K0 decreases by ≈ 0.75 log units from saturation pressure to 975 bar. The corresponding decrease of the apparent formation constant Q at I = 1 m is ≈ 0.6 log units. The increased dissociation at higher pressure leads to a decrease of the partial molal volume and entropy due to the resulting higher electrostriction in the system.

Activity Coefficients of Aqueous Solutions of NaOH and KOH in Wide Concentration and Temperature Ranges

1996 ◽  
Vol 61 (11) ◽  
pp. 1549-1562 ◽  
Author(s):  
Jan Balej
Keyword(s):  
Experimental Data ◽  
Aqueous Solutions ◽  
Temperature Interval ◽  
Water Activity ◽  
Activity Coefficients ◽  
Correlation Equations ◽  
Wide Temperature Interval ◽  
Temperature Ranges ◽  
Mean Activity Coefficients

Up to now, there exist a quite wide temperature interval between 70 or 80 and 150 °C with no sufficiently reliable experimental data of mean activity coefficients for aqueous NaOH as well as KOH solutions. In order to fill this gap, it was tried to derive suitable correlation equations for this quantity in dependence on the molality (for NaOH in the range mNaOH = 2-25 mol kg-1, for KOH in the range mKOH = 2-18 mol kg-1) and temperature (in the range 0-200 °C for both kinds of solutions) on the basis of the available data of this quantity and with the use of the previously derived correlation equations for the water activity in aqueous solutions of NaOH and KOH under the same conditions. The comparison between the calculated and experimental data was discussed.

scholarly journals Composition dependent density of ternary aqueous solutions of ionic surfactants and salts

2021 ◽  
Author(s):  
Silvia M. Calderón ◽  
Nønne L. Prisle
Keyword(s):  
Aqueous Solutions ◽  
Atmospheric Aerosols ◽  
Pure Water ◽  
Sodium Dodecylsulfate ◽  
Ionic Surfactants ◽  
Model Parameters ◽  
Partial Molal Volume ◽  
Molal Volume ◽  
Mixing Ratios ◽  
Sodium Decanoate

AbstractSurfactants exist in atmospheric aerosols mixed with inorganic salts and can significantly influence the formation of cloud droplets due to bulk–surface partitioning and surface tension depression. To model these processes, we need continuous parametrizations of the concentration dependent properties of aqueous surfactant–salt solutions for the full composition range from pure water to pure surfactant or salt. We have developed density functions based on the pseudo-separation method and Young’s mixing rule for apparent partial molal volumes for solutions that mimic atmospheric droplets of marine environments. The developed framework requires only model parameters from binary water–salt and water–surfactant systems and includes the effect of salinity on micellization with composition-dependent functions for the critical micelle concentration (CMC). We evaluate different models and data available in the literature to find the most suitable representations of the apparent partial molal volume of sodium chloride (NaCl) in aqueous solutions and the CMC of selected atmospheric and model surfactants in pure water and aqueous NaCl solutions. We compare model results to experimental density data, available in the literature and obtained from additional measurements, for aqueous solutions containing one of the ionic surfactants sodium octanoate, sodium decanoate, sodium dodecanoate or sodium dodecylsulfate mixed with NaCl in different relative ratios. Our model follows the experimental trends of increasing densities with increasing surfactant concentrations or increasing surfactant–salt mixing ratios both, below and above the CMC, capturing the effect of the inorganic salt on the surfactant micellization.

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