THE PARTIAL MOLAL VOLUMES OF IONS IN AQUEOUS SOLUTION: I. DEPENDENCE ON CHARGE AND RADIUS

1956 ◽  
Vol 34 (9) ◽  
pp. 1209-1216 ◽  
Author(s):  
A. M. Couture ◽  
K. J. Laidler
Keyword(s):  
Ionic Crystal ◽  
Infinite Dilution ◽  
Hydrogen Ion ◽  
Empirical Equations ◽  
Density Data ◽  
A Value ◽  
Partial Molal Volumes ◽  
Solutions Of Electrolytes ◽  
Molal Volumes ◽  
Charge And Radius

The density data for aqueous solutions of electrolytes have been analyzed, and partial molal volumes at infinite dilution have been calculated. The values are shown to be additive, and a set of volumes for individual ions has been prepared, based arbitrarily on a value of zero for the hydrogen ion. It is shown that for a given value of the charge the volumes vary linearly with the cube of the ionic crystal radii, and for a given radius vary with the first power of the charge. In the case of cations the equation obeyed is[Formula: see text]while for anions[Formula: see text]If the volume of the hydrogen ion is taken as −6 ml. instead of zero the same equation is obeyed for both cations and anions, namely[Formula: see text]The empirical equations are discussed in terms of a simple model for ions in solution.

THE PARTIAL MOLAL VOLUMES OF IONS IN AQUEOUS SOLUTION: II. AN EMPIRICAL EQUATION FOR OXY-ANIONS

1957 ◽  
Vol 35 (3) ◽  
pp. 207-210 ◽  
Author(s):  
A. M. Couture ◽  
K. J. Laidler
Keyword(s):  
Aqueous Solution ◽  
Empirical Equation ◽  
Preceding Paper ◽  
Effective Radius ◽  
Density Data ◽  
A Value ◽  
Partial Molal Volumes ◽  
Molal Volumes ◽  
The One

The partial molal volumes of oxy-anions, obtained from density data, have been correlated with the radius, the charge, and the number of ligands of the ions. The volumes relative to a value of −6.0 ml. for the proton are represented by the equation:[Formula: see text]where r and z_ have the same significance as in the preceding paper on entropies. The equation is compared with the one for monatomic ions, and the significance of the effective radius r is discussed.

The apparent and partial molal volumes of K-montmorillonite

Clay Minerals ◽  
1972 ◽  
Vol 9 (4) ◽  
pp. 361-368 ◽  
Author(s):  
E. A. Ferreiro ◽  
A. K. Helmy
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Double Layer ◽  
Electric Double Layer ◽  
Particle Concentration ◽  
Pure Water ◽  
Density Data ◽  
Partial Molal Volumes ◽  
Electrostatic Contribution ◽  
Molal Volumes

AbstractThe partial and apparent molal volumes of K-bentonite in pure water and in 0·5 M KCl were determined using pycnometer density data. The values obtained were found to increase with particle concentration. Theoretical values of the electrostatic contribution to the volume of particles calculated from an assumed model based on the electric double layer theory, gave values different from those found experimentally. This is explained as due largely to the uncertainties in the value of the clay specific surface area as well as to the assumed ideality of the model used.

Partial molal volumes of some halobenzenes in carbon tetrachloride

1983 ◽  
Vol 61 (7) ◽  
pp. 1414-1416 ◽  
Author(s):  
Fereidoon Shahidi
Keyword(s):  
Carbon Tetrachloride ◽  
Infinite Dilution ◽  
Van Der Waals ◽  
Alkyl Halides ◽  
Substituted Benzenes ◽  
Halogen Atoms ◽  
Partial Molal Volumes ◽  
Molal Volumes

The partial molal volumes at infinite dilution [Formula: see text] for a number of halobenzenes are measured and related to their van der Waals volumes. Results indicate larger volume increments for halogen atoms in halobenzenes than those in alkyl halides. Possible explanations are forwarded. The effect of steric overcrowding in ortho-substituted benzenes on the [Formula: see text] values are evaluated.

THE ENTROPIES OF IONS IN AQUEOUS SOLUTION: I. DEPENDENCE ON CHARGE AND RADIUS

1956 ◽  
Vol 34 (8) ◽  
pp. 1107-1113 ◽  
Author(s):  
K. J. Laidler
Keyword(s):  
Aqueous Solution ◽  
Free Volume ◽  
Linear Dependence ◽  
Empirical Equations ◽  
Entropy Changes ◽  
Absolute Scale ◽  
A Value ◽  
Born Equation ◽  
Charge And Radius ◽  
Electrostatic Theory

Empirical equations recently proposed for the entropies of ions in aqueous solution involve a linear dependence on the first power of the valency z and, in some cases, an inverse dependence on the square of a modified radius. Such relationships have no fundamental validity since the entropies are related arbitrarily to a zero value for the proton. It is shown that the entropy changes for reactions of various ionic types indicate that the entropy must depend on z2, as proposed by Born on the basis of simple electrostatic theory. When the entropies of monatomic ions are related to the absolute scale, in which the proton has a value of −5.5 e.u., they are found to vary linearly with z2/ru, where ru is the univalent radius defined by Pauling. The slope is found to be close to that predicted by the Born equation, and the non-electrostatic part of the entropy is shown to correspond to the movement of the ion in a free volume of 0.73 eu. Å.

The metachor as a characteristic of the association of electrolytes in aqueous solutions

1984 ◽  
Vol 49 (5) ◽  
pp. 1061-1078 ◽  
Author(s):  
Jiří Čeleda ◽  
Stanislav Škramovský
Keyword(s):  
Aqueous Solutions ◽  
Apparent Volume ◽  
Solutions Of Electrolytes ◽  
Molal Volumes ◽  
The Difference ◽  
High Concentrations ◽  
Experimental Values ◽  
Suitable Characteristic ◽  
Association Of Ions ◽  
Very High

Based on the earlier paper introducing a concept of the apparent parachor of a solute in the solution, we have eliminated in the present work algebraically the effect which is introduced into this quantity by the additivity of the apparent molal volumes. The difference remaining from the apparent parachor after substracting the contribution corresponding to the apparent volume ( for which the present authors suggest the name metachor) was evaluated from the experimental values of the surface tension of aqueous solutions for a set of 1,1-, 1,2- and 2,1-valent electrolytes. This difference showed to be independent of concentration up to the very high values of the order of units mol dm-3 but it was directly proportional to the number of the free charges (with a proportionality factor 5 ± 1 cm3 mol-1 identical for all studied electrolytes). The metachor can be, for this reason, a suitable characteristic for detection of the association of ions and formation of complexes in the solutions of electrolytes, up to high concentrations where other methods are failing.

On the calculation of partial molar volumes at infinite dilution from experimental density data

2020 ◽  
pp. 1-7
Author(s):  
Jorge Álvarez Juliá ◽  
María Del Carmen Grande ◽  
Carmen Raquel Barrero ◽  
Carlos Miguel Marschoff
Keyword(s):  
Infinite Dilution ◽  
Partial Molar Volumes ◽  
Density Data ◽  
Molar Volumes ◽  
Experimental Density

Partial Molal Volumes of Aqueous Ions

1957 ◽  
Vol 61 (10) ◽  
pp. 1426-1429 ◽  
Author(s):  
Loren G. Hepler
Keyword(s):  
Partial Molal Volumes ◽  
Aqueous Ions ◽  
Molal Volumes
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