Sodium chloride diffusion coefficient

Light transmission L. L. Schramm and J.C.T. Kwak, op. cit. Electrophoretic mobility P. Bar-On, I. Shainberg, and I. Michaeli, Electrophoretic mobility of montmorillonite particles saturated with Na/Ca ions, J. Colloid Interface Sci. 33 471 (1970). Intrinsic viscosity I. Shainberg and H. Otoh, op. cit. Chloride exclusion volume J. E. Dufey, A. Banin, H. G. Laudelout, juid Y. Chen, Particle shape and sodium self-diffusion coefficient in mixed sodium-calcium montmorillonite. Soil Sci. Soc. Am. J. 40 310 (1976). 

The permeability tests for alkali metal ions in the aqueous solution were also conducted. When an aqueous salt solution moves to cell 2 through the membrane from cell 1, the apparent diffusion coefficient of the salt D can be deduced from a relationship among the cell volumes Vj and V2, the solution concentration cx and c2, the thickness of membrane, and time t6 . In Table 12, permeabilities of potassium chloride and sodium chloride through the 67 membrane prepared by the casting polymerization technique from the monomer solution in THF or DMSO are compared with each other and with that the permeability through Visking dialyzer tubing. The... 

The amount of hydrogen chloride captured as sodium chloride was proportional to square root of time and sodium diffusion coefficients in glass cullets calculated were 2.9 - 3.9xl0 m /s at 823K. Also, chlorine-firee char can be produced by steam decomposition, even though particle size issue remains. 

Traditionally, the penetration of chlorides and sodium is measured destructively by grinding layers of concrete and chemically analyzing the powder samples. These data are used to calculate diffusion coefficients for the ions. This procedure is very slow, has low spatial resolution, and is destructive. The measured data are critically important for the development of service life models and therefore a rapid, high-resolution method to monitor the ingress of these ions is desirable. 

Figure 5 The mutual diffusion coefficient, D, of sodium chloride as a function of reciprocal matrix hydration, H, in various methacrylate gels. HPMA-GMA polyfhydroxypro-pyl methacrylate-co-glyceryl methacrylate) HEMA polyfhydroxyethyl methacrylate) MMA-GMA poly(methyl methacrylate-co-glyceryl methacrylate) HEMA-MMA poly-(hydroxyethyl methacrylate-co-methyl methacrylate) HPMA-MMA polyfhydroxypropyl methacrylate-co-methyl methacrylate) HPMA-GDMA polyfhydroxypropyl methacry-late-co-glyceryl dimethacrylate). (From Ref. 64.)...

The diffusion coefficients of potassium and sodium chlorides in the membrane we have found to be independent of solution concentration within experimental error. The value of sodium chloride agrees well with those found by others bearing in mind the differences in the polymer and in the membrane casting procedures (5,13). 

Fell G.J.D. and Hutchison H. P. (1971) Diffusion coefficients for sodium and potassium chlorides in water at elevated temperatures. J. Chem. Eng. Data 16, 427-429. 

Figure 6.29 Diffusion coefficient measured directly (open circles) and calculated from electrical conductivity data (closed circles) for Na+ in sodium chloride. From W. D. Kingery, H. K. Bowen, and D. R. Uhhnann, Introduction to Ceramics. Copyright 1976 by John Wiley Sons, Inc. This material is used by permission of John Wiley Sons, Inc.

Spiegler has used the friction model to describe a system consisting of sodium ions (1), chloride ions (2), water (3) and a charged matrix (4). He neglects the interaction of the sodium ions with the chloride ions. Then five independent measurements are needed to calculate the friction coefficients. Spiegler chose to be measured the self-diffusion coefficient... 

The self-diffusion coefficients of CF and Na" in molten sodium chloride are, respectively, 33 x 10 exp(-8500// 7) and 8x10 exp(-4000// 7) cm s". (a) Use the Nernst-Einstein equation to calculate the equivalent conductivity of the molten liquid at 935°C. (b) Compare the value obtained with the value actually measured, 40% less. Insofar as the two values are significantly different, explain this by some kind of structural hypothesis. 

Liquid toluene (C iHsCHj) was stored at6.4°C in an open top 20-cm-diameter cylindrical container. Tile vapor pressure of toluene at 6.4°C is 10 nun Hg. A gentle stream of fresh air at 6.4"C and 101.3 kPa was allowed to flow over the open end of the container. The rale of evaporation of toluene into air was measured to be 60 g/day. E.stimaie the concentration of toluene (in g/m ) at exactly 10 nun above the liquid surface. The diffusion coefficient of toluene at 2S° C is D.,a = 0.084 X 10-"inVs. 14-141 In an experiment, a sphere of crystalline sodium. chloride (NaCI) was suspended in a. stirred tank filled with water at 20°C. It-s initial mass was 100 g. In 10 minutes, the mass Of sphere was found to have decreased by 10 percent. The density of NaCl is 2160 kg/ra Its solubility in water at 20°C is 320 kg/m, Use these results to obalin an average value for the mass transfer coefficient. 

Interactions between oppositely charged micelles in aqueous solutions spontaneously form vesicles. The self-diffusion coefficient of water and 2H relaxation of 2H-labeled dodecyl trimethyl ammonium chloride of the dodecyl trimethyl ammonium chloride-sodium dodecyl benzenesulfonate systems show that in these mixtures there is limited growth of the micelles with changes in composition. The vesicles abruptly begin to form at a characteristic mixing ratio of the two surfactants. The transition is continuous.205 Transformation from micelle to vesicle in dodecyl trimethyl ammonium chloride-sodium perfluoro-nonanoate aqueous solution has been studied by self-diffusion coefficient measurements, and it was found that at a concentration of 35 wt% with a molar ratio of 1 1, the self-diffusion coefficient of the mixed micelles is far smaller than that of the two individual micelles.206 The characteristics of mixed surfactant... 

In the case of mixing primarily due to turbulent diffusion and dispersion, the Fickian transport coefficients are essentially independent of the chemical, so that the values of D determined from tracer experiments can be applied to other chemicals of interest in the same river. Two types of commonly used tracers are salts, such as sodium chloride (NaCl), and fluorescent dyes, such as rhodamine, which can be measured at very low concentrations. 

F = Faraday constant (96500 Ampere.sec/ equivalent) D = diffusion coefficient of sodium chloride at the boundary layer (cm2/sec)... 

It is usually assumed that the diffusion coefficient is independent of the concentration. However, experimental data [64,120,272,388,393,439,491] show that the diffusion coefficients in liquids often strongly depend on the concentration. In dilute solutions, an increase in the concentration always produces a decrease in the diffusion coefficient. For example, two grams of sodium chloride dissolved in one liter of water decreases the diffusion coefficient by 10%. Often the diffusion coefficient linearly decreases with the increase of the diffusing substance concentration (sugar, raffinase, etc.) in the water solution [64]. 

These equations mean that the flux of electrolyte through the ion exchange membrane is governed by the diffusion coefficient of the co-ion, not the counterion. For example, the diffusion flux of hydrochloric acid should be equal to that of sodium chloride in an ideal cation exchange membrane. 

Following the last glaciation, the salinity of the oceans decreased due to melting of the polar ice caps. This decrease in chloride and sodium and other major ions of sea water has led to a lowered concentration in the pore water of the upper seabed. By using the equation for diffusion distance versus time (ca. 10,000 years), calculate how deep this concentration decrease has diffused into the seabed. Diffusion coefficients are given in Chapter... 

Fig. 14.13 Cartoon illustrating how gas hydrate formation increases the salinity of the adjacent interstitial pore fluid, and subsequent dissipation of the chloride anomaly via diffusion over time. A. Shows system before hydrate formation, sodium and chloride ions homogeneously distributed in the pore fluid. B. When gas hydrate forms, ions are excluded from the crystal lattice, and the pore fluids become saltier at the foci of hydrate formation. Right panel illustrates a 56 mM anomaly created by formation of gas hydrate that occupies 9% of the pore space. C. Over time the excess ions diffuse away, as illustrated by the diffusional decay model showing dissolved chloride profiles at 1,000 and 10,000 years. D. After 100,000 years, the chloride anomaly is smaller than that which can be detected with current analytical techniques. The 1-dimensional model assumes that the half width of the concentration spike to be 5 meters, a sediment porosity of 50% and the free solution diffusion coefficient for the chloride ion of 1.86 x 10 cm s" at 25 °C (modified from Ussier and Pauli 2001).

Figure 1.26 Diffusion coefficients in aqueous KCl solutions at 25 °C (solution age = 24 h) in the metastable region, (Reproduced from Y.C. Chang and A.S. Myerson (1985), The Diffusivity of Potassium Chloride and Sodium Chloride in Concentrated, Saturated, and Supersaturated Aqueous Solutions, AIChE 7. 31, pp. 890 894. Used by permission of the American Institute of Chemical Engineers. 1985 AIChE.)...

To determine the kinematic diffusion coefficient of sodium chloride at several concentrations and to compare with the calculated value at infinite dilution. 

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