Calculation of the density of aqueous solutions of strong electrolytes from individual ionic parameters

1983 ◽  
Vol 48 (6) ◽  
pp. 1538-1551 ◽  
Author(s):  
Jiří Čeleda
Keyword(s):  
Experimental Data ◽  
Aqueous Solutions ◽  
Concentration Dependence ◽  
Volume Concentration ◽  
Apparent Molar Volumes ◽  
Aqueous Electrolytes ◽  
Molar Volumes ◽  
Strong Electrolytes

Based on a hypothesis verified earlier, according to which the concentration dependence of apparent molar volumes of ions in aqueous solutions is caused by their dehydration due to the decrease of the volume concentration of water, a method for the calculation of the density of concentrated aqueous electrolytes from individual ionic constants is proposed. The theory is verified by comparing with experimental data from the literature (420 solutions of 57 electrolytes).

On theory of apparent molar volumes in concentrated aqueous solutions of strong electrolytes

1988 ◽  
Vol 53 (3) ◽  
pp. 446-458 ◽  
Author(s):  
Jiří Čeleda
Keyword(s):  
Aqueous Solutions ◽  
Volume Fraction ◽  
Biological Systems ◽  
The State ◽  
Apparent Molar Volumes ◽  
Solution Temperature ◽  
Molar Volumes ◽  
Concentrated Aqueous Solutions ◽  
Free Ion ◽  
Strong Electrolytes

On the basis of the method reported in the previous work, according to which close-packed hydration sheaths of ions are surrounded by excess voids which in the above model were replaced by contact gap of width d0 independent of temperature and concentration, it is inferred in the present study that on extrapolating the apparent volumes of strong electrolytes to zero volume fraction of water in solution, temperature-independent water-free ion volumes Φ’i are obtained. These volumes correspond to the state in which the contact gap is shifted up to the very surface of ions, without changing its width d0 = 39 ± 2 pm. The volumes Φ’i show additivity and acquire thus the properties of parameters which are applicable to calculation of the density of aqueous solutions of strong electrolytes as well as of their mixtures up to the highest possible concentrations. With Li+ and Na+ ions, the condition of temperature invariance of Φ’i results in that the hydrate nucleus is not naked cation but a species MH2O+ analogous to H3O+ ion. This explains likely the different function of Na+ and K+ ions in biological systems (especially concerning their permeation through membranes). In the case of Mg2+, Ca2+, Sr2+, and Ba2+ ions, the hard-body centre of their hydrates is formed by hexaaqua-complexes.

scholarly journals Density and Viscosity of LiCl, LiBr, LiI and Kcl in Aqueous Methanol at 313.15K

2021 ◽  
Vol 37 (5) ◽  
pp. 1083-1090
Author(s):  
V. V. Kadam ◽  
A. B. Nikumbh ◽  
T. B. Pawar ◽  
V. A. Adole
Keyword(s):  
Experimental Data ◽  
Dielectric Constant ◽  
Apparent Molar Volumes ◽  
Strong Electrolyte ◽  
Aqueous Methanol ◽  
Molar Volumes ◽  
Solvent Interactions ◽  
Viscosity Coefficients ◽  
Physicochemical Processes ◽  
Increase With Increase

The densities and viscosities of electrolytes are essential to understand many physicochemical processes that are taking place in the solution. In the present research, the densities and viscosities of lithium halides, LiX (X = Cl, Br, I ) and KCl in (0, 20, 40, 50, 60, 80 and 100) mass % of methanol + water at 313.15K were calculated employing experimental densities (ρ), the apparent molar volumes( ϕv) and limiting apparent molar volumes (0v) of the electrolytes. The (0v) of electrolyte offer insights into solute-solution interactions. In terms of the Jones-Dole equation for strong electrolyte solution, the experimental data of viscosity were explored. Viscosity coefficients A and B have been interpreted and discussed. The B-coefficient values in these systems increase with increase of methanol in the solvents mixtures. This implied that when the dielectric constant of the solvent decreases, so do the solvent-solvent interactions in these systems.

Apparent molar heat capacities and volumes of some aqueous solutions of aliphatic amino acids at 288.15, 298.15, 313.15, and 328.15 K

1994 ◽  
Vol 72 (2) ◽  
pp. 362-368 ◽  
Author(s):  
Andrew W. Hakin ◽  
Michelle M. Duke ◽  
Sheri A. Klassen ◽  
Robert M. McKay ◽  
Kathryn E. Preuss
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Aqueous Solutions ◽  
Equilibrium Constants ◽  
Heat Capacities ◽  
Apparent Molar Volumes ◽  
Protein Chemistry ◽  
Standard State ◽  
Apparent Molar Heat Capacities ◽  
Molar Volumes

The thermodynamics of amino acid systems are key to the understanding of protein chemistry. We have found that many previous studies of the apparent molar volumes and heat capacities of aqueous solutions of amino acids were conducted at the standard temperature of 298.15 K. This does not allow for the fact that most biological processes occur at temperatures removed from this standard condition.In an attempt to address this imbalance we have measured densities and heat capacities for aqueous solutions of glycine, L-alanine, L-serine, and L-threonine at 288.15, 298.15, 313.15, and 328.15 K using a Picker flow microcalorimeter. Apparent molar volumes and heat capacities, and the associated standard state partial molar properties have been calculated. Constant pressure variations of revised Helgeson, Kirkham, and Flowers equations have been fitted to calculated standard state volumes and heat capacities over the temperature range 288.15 to 328.15 K. These equations may be used to estimate standard state volumes and heat capacities, and hence equilibrium constants, for aqueous amino acid systems at higher temperatures.

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