Debye-Huckel theory of electrolytes

De Broukere mean diameter, 18 135 Debt capital cost, 9 542 Debt ratio (DR), 9 541 Debt structure, 9 542-543 Deburring, surface, 9 597-598 Debutanizer, 10 614—615 Debye-Huckel theory, of electrolytes, 3 415 18... 

To determine the spatial variation of a static electric field, one has to solve the Poisson equation for the appropriate charge distribution, subject to such boundary conditions as may pertain. The Poisson equation plays a central role in the Gouy-Chapman (- Gouy, - Chapman) electrical - double layer model and in the - Debye-Huckel theory of electrolyte solutions. In the first case the one-dimensional form of Eq. (2)... 

Oka, from the Debye-Huckel theory of electrolytes, found ... 

Then, about 1904, it was pointed out by A. A. Noyes in this country and Sutherland in England that many properties of solutions of salts and strong acids (such as their color) suggest that most salts and strong acids are completely ionized in dilute solution. This view has been generally accepted since 1923, when a quantitative theory of the interactions of ions in solution was developed by Debye and Hiickel. This theory is called the Debye-Huckel theory of electrolytes. 

From the Debye-Huckel theory of electrolytes, the limiting (infinite dilution) law gives the mean activity coefficient of the ion as... 

He was awarded the Ph.D. degree in 1908 while serving as a professor of theoretical physics at the Ludwig-Maximillian University in Munich. While at the University of Zurich (1920-1927) he collaborated with Dr. Huckel in the development of the Debye-Huckel theory of electrolytes in solution. 

We shall just mention here that the simple association theory may be extended by considering the interactions between defects in solution in a medium with dielectric constant a [14]. This is analogous to the Debye-Huckel theory of electrolytic solutions. As a result, the mole fractions of charged point defects of sort i in the mass action laws have to be replaced by their corresponding activities which according to Debye-Huckel are of the form... 

Debye was responsible for theoretical treatments of a variety of subjects, including molecular dipole moments (for which the de-bye is a non-SI unit). X-ray diffraction and scattering, and light scattering. His theories relevant to thermodynamics include the temperature dependence of the heat capacity of crystals at a low temperature (Debye crystal theory), adiabatic demagnetization, and the Debye-Huckel theory of electrolyte solutions. In an interview in 1962, Debye said that he... 

There is large literature, and several computational methods, for this problem of a solute M immersed in a salt solution. In general, fine and detailed descriptions of the ions in the liquid are discarded, in favor of their approximation to point charges which are assumed to follow the Boltzmann distribution as in the Debye-Huckel theory of electrolytes. Since the Poisson-Boltzmann equation is not linear, an approximation based on its linearization is often used. By assuming e = constant, the equation takes the simple form ... 

C. W. Outhwalte, /. Chem. Phys., 50, 2277 (1969). Extension of the Debye-Huckel Theory of Electrolyte Solutions. 

Battery electrolytes are concentrated solutions of strong electrolytes and the Debye-Huckel theory of dilute solutions is only an approximation. Typical values for the resistivity of battery electrolytes range from about 1 ohmcm for sulfuric acid [7664-93-9] H2SO4, in lead—acid batteries and for potassium hydroxide [1310-58-3] KOH, in alkaline cells to about 100 ohmcm for organic electrolytes in lithium [7439-93-2] Li, batteries. 

SIDEBAR 8.6 DEBYE-HUCKEL THEORY OF DILUTE ELECTROLYTES... 

The scattering center is the metal ion, the Coulomb potential of which is screened in the manner of the Debye-Huckel theory of weak electrolytes. The screened potential has the form... 

Measurement of the potential by means other than electro-kinetic measurement. G. S. Hartley and J. W. Roe1 point out that the potential determines the distribution of ions near a surface in the same manner as the potential just outside an ion controls the ionic atmosphere in the Debye-Huckel theory of strong electrolytes. There is a simple relation between the concentration of an ion in the layer next to a surface and in the bulk solution at a distance from the surface and the potential, so that if a means can be found of measuring the concentration of an ion in the surface and in the solution, it should be possible to estimate the potential of that surface. 

Kirkwood, J. G. and Poirier, J. C., The statistical mechanical basis of the Debye-Huckel theory of strong electrolytes. J. Phys. Chem. 86, 591-596 (1954). 

Metals, semiconductors, electrolyte solutions, and molten salts have in common the fact that they contain given or variable densities of mobile charge carriers. These carriers move to screen externally imposed or internal electrostatic fields, thus substantially affecting the physics and chemistry of such systems. The Debye-Huckel theory of screening of an ionic charge in an electrolyte solution is an example familiar to many readers. 

In the case of ionised solutes, an increase in the salt concentration results in a reduction in the electrostatic repulsion between solute molecules as may be predicted by the modified Debye-Huckel theory of dilute electrolytes (Lietzke et al., 1968). Therefore, for an ionised solute, as the salt concentration is increased, the electrostatic component of the solvophobic equation is increased, resulting in an initial decrease of the In k term at low salt concentrations. As the salt concentration is further increased the surface tension effects increase and In k increases. 

Huckel began his quantum theoretical studies of chemical bonding following postdoctoral work at several locations, the most important one being Zurich, where he developed together with his Ph.D. advisor Peter Debye the well-known Debye-Hiickel theory of electrolytic... 

Mechanical Basis of the Debye-Huckel Theory of Strong Electrolytes. 

One of the highlights of the Meeting was the presentation by G.S. Hartley of UCL on the Debye-Huckel Theory of Colloidal Electrolytes. This paper is still the foundation of current discussions on this topic. 

This d is equal to the thickness of the ionic atmosphere in the Debye-Huckel theory for electrolytes for a 1 1 electrolyte, it increases with decreasing concentration ( ) and decreases with increasing concentrations. Thus the capacity of the double layer can also be written as... 

Theoretical investigations lead to the conclusion that there is a far going analogy between the structure of the double layer and that of the Debye-Huckel ionic atmospheres, In fact, considerations of this kind on the double layer arc older than the Debye-Huckel theory of strong electrolytes. 

Huckel was a German physi cal chemist Before his theo retical studies of aromaticity Huckel collaborated with Peter Debye in developing what remains the most widely accepted theory of electrolyte solutions... 

A finite time is required to reestabUsh the ion atmosphere at any new location. Thus the ion atmosphere produces a drag on the ions in motion and restricts their freedom of movement. This is termed a relaxation effect. When a negative ion moves under the influence of an electric field, it travels against the flow of positive ions and solvent moving in the opposite direction. This is termed an electrophoretic effect. The Debye-Huckel theory combines both effects to calculate the behavior of electrolytes. The theory predicts the behavior of dilute (<0.05 molal) solutions but does not portray accurately the behavior of concentrated solutions found in practical batteries. 

If the activity coefficients are estimated from the Debye-Huckel theory in dilute regions of simple electrolyte systems, we have for aqueous solutions at 25 °C,... 

Further simphfication of the SPM and RPM is to assume the ions are point charges with no hard-core correlations, i.e., du = 0. This is called the Debye-Huckel (DH) level of treatment, and an early Nobel prize was awarded to the theory of electrolytes in the infinite-dilution limit [31]. This model can capture the long-range electrostatic interactions and is expected to be valid only for dilute solutions. An analytical solution is available by solving the Pois-son-Boltzmann (PB) equation for the distribution of ions (charges). The PB equation is... 

As a result of these electrostatic effects aqueous solutions of electrolytes behave in a way that is non-ideal. This non-ideality has been accounted for successfully in dilute solutions by application of the Debye-Huckel theory, which introduces the concept of ionic activity. The Debye-Huckel Umiting law states that the mean ionic activity coefficient y+ can be related to the charges on the ions, and z, by the equation... 

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