Electrolyte binary, solutions

Binary electrolyte solutions contain just one solute in addition to the solvent (i.e., two independent components in all). Multicomponent solutions contain several original solutes and the corresponding number of ions. Sometimes in multicomponent solutions the behavior of just one of the components is of interest in this case the term base electrolyte is used for the set of remaining solution components. Often, a base electrolyte is acmaUy added to the solutions to raise their conductivity. 

For the conductivity of a binary electrolyte solution with the degree of dissociation a, we have, according to Fq. (1.12),... 

It follows (when taking into account that = x z = Zj) that the molar conductivity of binary electrolyte solutions is given by... 

Cruz, Jose-Luis and H. Renon, "A New Thermodynamic Representation of Binary Electrolyte Solutions Nonideality in the Whole Range of Concentrations," AIChE J., 1978, 24, 817. 

CRUZ (7) equation for gE of binary electrolyte solution which incorporates a DEBYE - HUCKEL term, a BORN - DEBYE - MAC. AULAY contribution for electric work, and NRTL equation, can be used to represent the vapor-liquid equilibria of volatile electrolyte in the whole range of concentration. 

Bennion, D. N. Mass Transport of Binary Electrolyte Solutions in Mewbranes, Water Resources Center Desalination Report No. 4 Department of Engineering, University of California—Los Angeles 1966. 

The osmotic coefficients of the binary electrolyte solutions, 02 and 0ref were calculated by means of the Lietzke-Stoughton relation (11) enlarging the Debye-Hiickel equation with empirical terms ... 

B. Liquid-Liquid Demixings in Binary Electrolyte Solutions... 

In this chapter the thermodynamic analysis of the Nd(N03)3-HN03-H20 system is presented. The determination of the activity and the activity coefficient of the free neodymium (III) ion and the development of an accurate model for the activity behavior of aqueous binary electrolyte solutions consisting of the neodymium nitrate and nitric acid are presented. 

Figure 6. The vapor pressure of the Nd(NOs)3-HN0s-H20 binary electrolyte solution...

Figure 8. The water activity in the Nd(N03)3-HN03-H20 binary electrolyte solution to the water activity referenced to pure HNOs as a function of the ionic strength fraction of Nd(NOs)s...

Hamed s plot for a binary electrolyte solution at constant total ionic strength is presented in Figure 9. The utility of this plot can be seen from Equation 27. Because of the linearity of the data, the slope and intercept of each line determines the value of the Q coefficients at each total ionic strength. 

It was shown in Section 3.4 that if the bulk of a dilute binary electrolyte solution may be assumed electrically neutral, then the distribution of reduced ion concentration is governed by the same convective diffusion equation as for a neutral species with an effective diffusion coefficient related to the difference in charge and diffusion coefficients of the positive and negative ions. Once the concentration distribution has been found, the potential distribution in the solution can be obtained by integrating the equation for current continuity (Eq. 3.4.16) to give... 

For most binary electrolyte solutions 9n/9c is constant. Since both the length of the pathway where the laser beam is influenced by the concentration gradient and the refractive index n of the solution are constant, the deflection depends practically only on 9c/9c [867]. 

Alternatively a study can be realized for binary electrolyte solutions, MA, at varying concentrations [24] that provide. 

Zie is the charge of the species. Stern assumed the location of the adsorption ion at the outer Helmholtz plane separating the compact and diffuse layer, so that the potential in the work term in Eq. (71) corresponds to the potential difference across the diffuse layer. The combination of Eqs. (70a) and (71) gives Stern s expression for the adsorption isotherm from a binary electrolyte solution for the case of a single ionic species being accumulated in the adsorbed state ... 

Analytical chemistry has found great utility in conductimetric measurements in spite of its apparent nonspecificity. Rapid quantitative accuracy of a few tenths of a percent may be quickly accomplished by direct conductimetric determination of binary electrolytic solutions such as aqueous acids, bases, or salts. A nearly linear increase in conductivity is observed for solutions containing as much as 20% of solute. The concentration of strong solutions, such as the salinity of seawater, may be determined from conductance measurements traces of electrolyte impurities, such as the impurity in ultrapure water, may be reported at the pgl level. Conductimetric titrations may increase the accuracy of endpoint detection and permit titrimet-ric analysis of weak electrolytes, such as boric acid, which is not feasible by potentiometric or colorimetric... 

The equations for a binary electrolyte solution are relatively simple. For mixed electrolytes they get a bit more complicated. We look first at the equations for a binary electrolyte. 

In a binary electrolyte solution such as this one, terms containing A, 0, or tf/ are zero, since these involve interactions with two dissimilar anions or cations. In most such cases, the parameter is unnecessary, because it is invoked to account for exceptionally strong ion-ion interactions. In fact, Pitzer shows that should approach -K/2 in the limit of infinite dilution, where K is the association constant for the ion-pair. The work of Harvie and Weare (1980), Eugster, Harvie and Weare (1980), and Harvie, Eugster and Weare (1982), who modeled solubility equilibria in the multicomponent oceanic salt system is considered a milestone in the application of the Pitzer equations, and the set of parameters in Harvie, Mller and Weare (1984) is considered a sort of standard for modeling of seawater evaporitic systems. 

Ionic mobilities or diffusivities are measured experimentally by combining a number of independent dynamic experiments to isolate the transport properties of interest. Auxiliary experiments must also be performed to establish the thermodynamic properties of the solution. Eor the simplest case of a binary electrolytic solution (comprising an electrolyte and a neutral solvent) of a binary electrolyte (comprising one anion and one cation), there are three species (solvent 0, cations -I-, and anions -). This case requires that a single thermodynamic characterization be implemented to quantify the electrolyte activity as a function of composition. Subsequently, three independent dynamic measurements must be implemented to quantify the three independent relative diffusivities Z)+o, D q, and D+. ... 

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