Hostname: page-component-78c5997874-s2hrs Total loading time: 0 Render date: 2024-11-20T05:05:14.208Z Has data issue: false hasContentIssue false

Thermodynamic, Quasithermodynamic, and Nonthermodynamic Methods as Applied to the Electrochemistry of Clays

Published online by Cambridge University Press:  01 January 2024

C. Edmund Marshall*
Affiliation:
University of Missouri, Columbia, Missouri, USA
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

The consequences of a nonhomogeneous charge distribution in clay systems are first examined. The mean ionic activity is shown to be a geometrical rather than an arithmetical average. Potentiometrie methods of measurement, with (quasithermodynamic), and without (thermodynamic) liquid junctions are compared. The latter give chemical potentials of soluble molecular species or ratios of mean activities; neither of these affords a characterization of single cations in relation to clay surfaces. The quasithermodynamic method, like conductance measurements, affords data which can be interpreted directly in terms of single ions. The two are compared for dilute and more concentrated clay systems by using the ratio: “Cation conductivity/total conductivity of clay systems.” For dilute systems this ratio varies slowly and smoothly with concentration and with degree of saturation. High concentrations give an abnormally high value. Cataphoresis results are shown to be in agreement with conductance and Potentiometric data for dilute clay systems.

Type
Article
Copyright
Copyright © The Clay Minerals Society 1955

Footnotes

Contribution from the Missouri Agricultural Experiment Station, J oumal Series no. 159l. Approved by the Director.

References

Alexander, A. E., and Johnson, P., 1949, Colloid science: Oxford Univ. Press, v. 1, 554 p.Google Scholar
Aslying, H. C., 1954, The lime and phosphate potentials of soils; the solubility and availability of phosphates: Hydrotechnical Laboratory, Royal Veterinary and Agricultural College Bull., Yearbook 1954, Copenhagen, Denmark, p. 150.Google Scholar
Babcock, K. L., and Overstreet, R., 1953, On the use of calomel half cells to measure Donnan potentials: Science, v. 117, p. 686687.CrossRefGoogle ScholarPubMed
Beavers, A. H., and Marshall, C. E., 1951, The cataphoresis of clay minerals and factors affecting their separation: Soil Sci. Soc. Amer. Proc., v. 15, p. 142145.CrossRefGoogle Scholar
Bray, R. H., 1942, Ionic competition in base exchange reactions. J. Amer. Chem. Soc., v. 64, p. 954963.CrossRefGoogle Scholar
Davis, L. E., 1955, Ion pair activities in bentonite suspensions: in Clays and clay minerals. Natl. Acad. Sci.—Natl. Res. Council Pub. 395, p. 290295.Google Scholar
Eriksson, E., 1951, The significance of pH, ion activities and membrane potentials in colloidal systems: Science, v. 113, p. 418420.CrossRefGoogle ScholarPubMed
Jenny, H., and others, 1950, Concerning the measurement of pH, ion activities and membrane potentials in colloidal systems: Science, v. 112, p. 164167.CrossRefGoogle ScholarPubMed
Marshall, C. E., 1949, The colloid chemistry of the silicate minerals: Academic Press, N. Y., 180 p.Google Scholar
Marshall, C. E., 1951, Measurements in colloidal systems: Science, v. 113, p. 4344.CrossRefGoogle ScholarPubMed
Marshall, C. E., 1952, Potentiometric measurements in colloidal systems: Science, v. 115, p. 361362.CrossRefGoogle ScholarPubMed
Marshall, C. E., 1953, A critical review of the two preceding papers. Further brief comments: Soil Sci. Soc. Amer. Proc., v. 17, p. 218220, 221-222.Google Scholar
Marshall, C. E., and Krinbill, C. A., 1942, The clays as colloidal electrolytes: J. Phys. Chem., v. 46, p. 10771090.CrossRefGoogle Scholar
Mattson, S., 1929, The laws of soil colloidal behavior I: Soil. Sci., v. 28, p. 179220.CrossRefGoogle Scholar
Mukherjee, S. K., and Marshall, C. E., 1951, The electrochemical properties of mineral membranes. IX, Membrane characteristics of clay pastes: J. Phys. Colloidal Chem., v. 55, p. 6168.Google Scholar
My sels, K. J., 1951, Potentiometric measurements in (some) colloidal systems: Science, v. 114, p. 424425.CrossRefGoogle Scholar
My sels, K. J., 1953, On the interpretation of the use of calomel half cells to measure Donnan potentials: Science, v. 118, p. 603604.CrossRefGoogle Scholar
Overbeek, J. Th. G., 1953, Donnan E.M.F. and suspension effect: J. Colloid Sci., v. 8, p. 593605.CrossRefGoogle Scholar
Peech, M., Olsen, R. A., and Bolt, G. H., 1953, The significance Potentiometrie measurement involving liquid junction in clay and soil suspensions: Soil Sci. Soc. Amer. Proc., v. 17, p. 214218.CrossRefGoogle Scholar
Russell, E. W., and Cox, G. A., 1950, The direct determination of ionic activity products or ratios in soils: Fourth International Cong. Soil Sci., Amsterdam, Trans., v. 1, p. 138141.Google Scholar
Schofield, R. K., and Taylor, A. W., 1955, The measurement of the activities of bases in soils: J. Soil Sci., v. 6, p. 137146.CrossRefGoogle Scholar
Schuffelen, A. C., and Loojes, R., 1942: Proc. Ned. Akad. Wetench., v. 45, p. 726733 and 944-952.Google Scholar
Teräsvuori, A., 1930, Valtion Maatalouskoetorminnan Julkaisuja: no. 29, Helsinki, p. 7200.Google Scholar
Wiklander, L., 1951, Equilibria in ion exchange I: Acta Agr. Scand., v. 1, p. 190197.CrossRefGoogle Scholar
Woodruff, C. M., 1955, Cation activities in the soil solution and energies of cationic exchanges: Soil Sci. Soc. Amer. Proc., v. 19, p. 9899.CrossRefGoogle Scholar