Extension of some local composition models for correlation of the apparent molal volume of aqueous electrolytes at 298.15K

2004 ◽  
Vol 226 ◽  
pp. 91-96 ◽  
Author(s):  
Jaber Jahanbin Sardroodi ◽  
Mohammed Taghi Zafarani-Moattar
2017 ◽  
Vol 5 (10) ◽  
pp. 160-167
Author(s):  
Yasmin Akhtar

Densities, ultrasonic velocities and viscosities of L- Valine and L- Phenylalanine in aqueous sodium bromide (0.00, 0.025 and 0.05) m solutions have been determined experimentally at 308 and 313 K. The results obtained from density ultrasonic velocity and viscosity measurement have been used to calculate the apparent molal volume, фv, apparent molal, adiabatic compressibility ф Ks, partial molal volume ф0v at infinite dilution, partial molal adiabatic compressibility ф0Ks at infinite dilution, transfer volume ∆ф(tr), experimental slopes Sv and SKs,Falkenhagen coefficient A and  Jones-Dole B coefficient. The results are discussed in terms of the dehydration effect of the sodium bromide upon the amino acids and weak solute- solute and strong solute- solvent interactions. The properties of these amino acids in water and water + sodium bromide solution systems are discussed in terms of the charge, size and hydrogen bonding effect.


2017 ◽  
Vol 27 (4) ◽  
Author(s):  
Ahmed Mohammed Abbas ◽  
Zainab Wajdi Ahmed ◽  
Alaa Fadhil Sulaiman ◽  
Issam AbdalKreem AbdalLatif

In this study binary and ternary solutions are prepared by using the sodium acetate concentrations (0.1, 0.125, 0.2, 0.25, 0.4, 0.5, 0.8, 1 M) in water and acetone –water mixtures .The important parameters such as apparent molal volume, the partial molal volume transfer,  apparent  molal compressibility, free energy of activation of viscous flow and thermodynamic activation parameter (enthalpy and entropy) determined of sodium acetate in water , 20%, 40% ,60% and 80% V/V acetone –water mixtures at 298.15K, 303.15K, and 308.15K from density and viscosity measurements espectively. The limiting apparent molal volumes and experimental slopes were derived from the Masson equation, have been interpreted in terms of solute–solvent and solute–solute interactions  respectively. The viscosity data were analyzed using theJones–Dole equation and the derived parameter B - coefficient has also been interpreted in terms of solute–solvent interactions in the solutions. 


1976 ◽  
Vol 54 (4) ◽  
pp. 624-631 ◽  
Author(s):  
Carmel Jolicoeur ◽  
Ghyslain Lacroix

The density and specific heat of dilute aqueous solutions of various alcohols and polyols have been measured at 25 °C. Such measurements have been carried out for the following solutes: methanol, ethanol, n-propanol, n-butanol, isobutanol, s-butanol, tert-butyl alcohol, n-pentanol. 3-pentanol, neo-pentanol, ethyleneglycol, 1,4-butanediol, 1,6-hexanediol, dimethyl-2,2-propanediol, 1,1,1-tris(hydroxymethyl)ethane, and pentaerythritol.The limiting apparent molal volume [Formula: see text] and heat capacities [Formula: see text] derived from these data exhibit some variations among the properties of isomers (e.g. branched vs. normal alkyl groups), but these variations cannot be conclusively attributed to specific effects in the hydration of the alkyl groups. On the other hand, the data allows one to derive group contributions to [Formula: see text] and [Formula: see text] namely [Formula: see text] for the methylene group, [Formula: see text] for the OH functional group and [Formula: see text] for the C—H of a terminal methyl group.The concentration dependence of [Formula: see text] brings out some interesting new features. With most of the alcohols, [Formula: see text] decreases with concentration, in a way related to the degree of hydrophobicity of the alcohol. Solute–solute interactions contribute to reduce [Formula: see text] of the hydrophilic solutes, but the opposite effect is observed with the most hydrophobic alcohols.


Author(s):  
José Enrique Jaime-Leal ◽  
Adrián Bonilla-Petriciolet

In this study, several local composition models and stochastic optimization methods have been used and compared in data fitting of activity coefficients in aqueous electrolytes. We have utilized the electrolyte-NRTL model of Chen et al. and the modified Wilson models proposed by Xu and Macedo, and Zhao et al. to fit the activity coefficients of several quaternary ammonium salts in water at 25°C. These electrolytes have interesting properties for their application as ionic liquids. However, the modeling of their thermodynamic behavior using local composition models is a global optimization problem. In this study, several stochastic optimization methods have been used to solve this optimization problem and their numerical performances have been compared. Specifically, we have tested the classical Simulated Annealing and the hybrid methods: Direct Search Simulated Annealing, Simplex Coding Genetic Algorithm, Simulated Annealing Heuristic Pattern Search, and Directed Tabu Search. Our results show that Simulated Annealing is a suitable tool for data fitting of the activity coefficients of aqueous electrolytes. Finally, the tested models can satisfactorily correlate the mean activity coefficients of electrolytes treated in this study, and are suitable for process design.


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