Pressions de vapeur des mélanges eau – nitrate d'éthylammonium à 298,15 K. Propriétés thermodynamiques des milieux eau – sel fondu

1985 ◽  
Vol 63 (12) ◽  
pp. 3587-3592 ◽  
Author(s):  
M. Biquard ◽  
P. Letellier ◽  
M. Fromon
Keyword(s):  
Activity Coefficient ◽  
Empirical Equation ◽  
Pure Water ◽  
Partial Molar Volumes ◽  
Pressure Measurements ◽  
Text Interpretation ◽  
Wide Range ◽  
Ethylammonium Nitrate ◽  
Vapor Pressure Measurements ◽  
Fused Salt

The activity and activity coefficient of water in water and ethylammonium nitrate (EAN) mixtures were determined by vapor pressure measurements between pure water and pure fused salt at 298.15 K. For a wide range of mole fractions of salt, (0.3 < X ≤ 1) the behaviour of water can be described very accurately by a "one parameter" empirical equation which involves activity coefficient, γE, mole fraction of EAN, and limiting Gibbs energy of the dilution of water in pure fused salt, [Formula: see text]:[Formula: see text]Interpretation of experimental results was also attempted by use of the B.E.T. equation. It appears that the energy, ΔEd = E − EL, in those solutions is very low. Partial molar volumes of water and salt are also discussed in relation to empirical and B.E.T. equations. It can be shown that the two equations lead to similar results.

Propriétés volumiques du nitrate d'éthylammonium fondu à 298 K et de ses mélanges avec l'eau

1985 ◽  
Vol 63 (3) ◽  
pp. 565-570 ◽  
Author(s):  
M. Hadded ◽  
M. Biquard ◽  
P. Letellier ◽  
R. Schaal
Keyword(s):  
Molar Volume ◽  
Salt Water ◽  
Pure Water ◽  
Molar Fraction ◽  
Partial Molar Volumes ◽  
Intrinsic Volume ◽  
Ethylammonium Nitrate ◽  
Actual Volume ◽  
Concentrated Solution ◽  
Fused Salt

Partial molar volumes of water and ethylammonium nitrate EAN are determined accurately in all water–EAN mixtures, between pure water and pure fused salt at 298 K. It has been found that the partial molar volume of water decreases linearly with molar fraction of salt, x, in concentrated solution of EAN (C > 2 mol L−1, x > 0.04). The main thermodynamic relations are established to describe the volumetric behaviour of salt, water, and solution. It has been shown that the intrinsic volume of salt can be identified roughly with the molar volume of the pure fused salt and the value of apparent molar volume of water with the actual volume of water in solution.

Some thermodynamic properties of the sulfolane–benzene and sulfolane–dichloromethane systems

1969 ◽  
Vol 47 (22) ◽  
pp. 4195-4198 ◽  
Author(s):  
R. L. Benoit ◽  
J. Charbonneau
Keyword(s):  
Thermodynamic Properties ◽  
Vapor Pressure ◽  
Infinite Dilution ◽  
Partial Molar Volumes ◽  
Refractive Indices ◽  
Pressure Measurements ◽  
Free Energies ◽  
Volumes Of Mixing ◽  
Excess Partial Molar Volumes ◽  
Vapor Pressure Measurements

Molar excess free energies of the systems sulfolane-benzene and sulfolane–dichloromethane have been calculated from static vapor pressure measurements at 30.00 °C. Refractive indices, excess partial molar volumes of mixing, and enthalpies of mixing at infinite dilution of benzene and dichloromethane were also determined.

scholarly journals Water Activity

2012 ◽  
Vol 27 ◽  
pp. 565-569 ◽  
Author(s):  
O. F. Nielsen ◽  
M. Bilde ◽  
M. Frosch
Keyword(s):  
Surface Tension ◽  
Vapor Pressure ◽  
Aqueous Solutions ◽  
Vapour Pressure ◽  
Pure Water ◽  
Free Water ◽  
Water Molecules ◽  
Pressure Measurements ◽  
Metabolic Activities ◽  
Vapor Pressure Measurements

Microorganisms require water for their metabolic activities. Only a fraction of water in foodstuffs, the so-called free water, is available for this purpose. The amounts of free water previously estimated by two different methods (Frosch et al. (2010), Frosch et al. (2011), and Low (1969)) are compared for aqueous solutions of four electrolytes, NaCl, NH4Cl, Na2SO4, (NH4)2SO4: (i) vapour pressure measurements of the solutions relative to that of pure water (water activities) and (ii) low-wavenumber Raman spectra in the R(ν)-representation. For each electrolyte deviations were found between results from the two methods. All water molecules in the illuminated volume contribute to the Raman data. The vapor pressure measurements refer to water molecules at the water/atmosphere interface where surface tension is important. Differences in surface tension for the four electrolytes qualitatively explain deviations between the amounts of “free water” observed by the two methods.

scholarly journals Thermochemistry of Polonium Evaporation from LBE

Thermo ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 251-261
Author(s):  
Alexander Aerts
Keyword(s):  
Vapor Pressure ◽  
Activity Coefficient ◽  
Ab Initio ◽  
Chemical Species ◽  
Pressure Measurements ◽  
Chemical Equilibria ◽  
Limit Activity Coefficient ◽  
Nuclear Systems ◽  
Dilute Limit ◽  
Vapor Pressure Measurements

Polonium is formed in relatively large quantities in lead-bismuth eutectic (LBE) cooled nuclear systems. Because of its radiotoxicity and volatility, a good understanding of the chemical equilibria governing polonium release from LBE is required. In this work, a set of thermochemical data is derived for the chemical species involved in the equilibrium between a solution of polonium in LBE and its vapor in inert conditions. The data were obtained by matching thermochemical models with experimental vapor pressure measurements and ab initio results. The dilute-limit activity coefficient of dissolved polonium in LBE is estimated, as well as the solubility of solid lead polonide in LBE. The results indicate that polonium evaporates from LBE according to the experimentally determined Henry’s law, up to dissolved polonium concentrations well above that expected in LBE cooled nuclear systems.

Solution chemistry effects on the solvation shell of metal ions

2020 ◽  
Author(s):  
Xiangwen Wang ◽  
Dimitrios Toroz ◽  
Seonmyeong Kim ◽  
Simon Clegg ◽  
Gun-Sik Park ◽  
...  
Keyword(s):  
Metal Ions ◽  
Pure Water ◽  
Solvation Shell ◽  
Solution Chemistry ◽  
Chemical Characteristics ◽  
Velocity Autocorrelation Function ◽  
Ionic Solvation ◽  
General Terms ◽  
Alkaline Earth Metal Ions ◽  
Wide Range

<div> <p>As natural aqueous solutions are far from being pure water, being rich in ions, the properties of solvated ions are of relevance for a wide range of systems, including biological and geochemical environments. We conducted ab initio and classical MD simulations of the alkaline earth metal ions Mg<sup>2+</sup> and Ca<sup>2+</sup> and of the alkali metal ions Li<sup>+</sup>, Na<sup>+</sup>, K<sup>+</sup> and Cs<sup>+</sup> in pure water and electrolyte solutions containing the counterions Cl<sup>–</sup> and SO<sub>4</sub><sup>2–</sup>. Through a detailed analysis of these simulations, this study reports on the effect of solution chemistry (composition and concentration of the solution) to the ion–water structural properties and interaction strength, and to the dynamics, hydrogen bond network, and low-frequency dynamics of the ionic solvation shell. Except for the ion–water radial distribution function, which is weakly dependent on the counter-ions and concentrations, we found that all other properties can be significantly influenced by the chemical characteristics of the solution. Calculation of the velocity autocorrelation function of magnesium ions, for example, shows that chlorine ions located in the second coordination shell of Mg<sup>2+</sup> weaken the Mg(H<sub>2</sub>O)<sub>6</sub><sup>2+</sup> hydration ‘cage’ of the cation. The result reported in this study suggest that ionic solvation shell can be significantly influenced by the interactions between other ions present in solution ions, especially those of opposite charge. In more general terms, the chemical characteristics of the solution, including the balance between ion-solvent and ion-ion interactions, could result in significant differences in behavior and function of the ionic solvation shell.</p> </div>

Wetting of glass surface using natural surfactants

2020 ◽  
Vol 12 ◽  
Author(s):  
Nihar Ranjan Biswal
Keyword(s):  
Contact Angle ◽  
Glass Surface ◽  
Pure Water ◽  
Amyl Alcohol ◽  
Synthetic Surfactant ◽  
Wide Range ◽  
Different Types ◽  
Natural Surfactants ◽  
Triton X ◽  
Solid Liquid

Background: Surfactant adsorption at the interfaces (solid–liquid, liquid–air, or liquid–liquid) is receiving considerable attention from a long time due to its wide range of practical applications. Objective: Specifically wettability of solid surface by liquids is mainly measured by contact angle and has many practical importances where solid–liquid systems are used. Adsorption of surfactants plays an important role in the wetting process. The wetting behaviours of three plant-based natural surfactants (Reetha, Shikakai, and Acacia) on the glass surface are compared with one widely used nonionic synthetic surfactant (Triton X-100) and reported in this study. Methods: The dynamic contact angle study of three different types of plant surfactants (Reetha, Shikakai and Acacia) and one synthetic surfactant (Triton X 100) on the glass surface has been carried out. The effect of two different types of alcohols such as Methanol and amyl alcohol on wettability of shikakai, as it shows little higher value of contact angle on glass surface has been measured. Results: The contact angle measurements show that there is an increase in contact angle from 47° (pure water) to 67.72°, 65.57°, 68.84°, and 68.79° for Reetha, Acacia, Shikakai, and Triton X-100 respectively with the increase in surfactant concentration and remain constant at CMC. The change in contact angle of Shikakai-Amyl alcohol mixtures are slightly different than that of methanol-Shikakai mixture, mostly there is a gradual increase in contact angle with the increasing in alcohol concentration. Conclusion: There is no linear relationship between cos θ and inverse of surface tension. There was a linear increase in surface free energy results with increase in concentration as more surfactant molecules were adsorbing at the interface enhancing an increase in contact angle.

Rapid Vapor-Collection Method for Vapor Pressure Measurements of Low-Volatility Compounds

2020 ◽  
Vol 92 (24) ◽  
pp. 16253-16259
Author(s):  
Megan E. Harries ◽  
Cheryle N. Beuning ◽  
Bridger L. Johnston ◽  
Tara M. Lovestead ◽  
Jason A. Widegren
Keyword(s):  
Vapor Pressure ◽  
Pressure Measurements ◽  
Collection Method ◽  
Vapor Collection ◽  
Vapor Pressure Measurements
Sign in / Sign up

Export Citation Format

Share Document