Acidic properties of dialyzed alumina and representative clay minerals were studied by performing titrations with various bases. For the first group of experiments the titrations were made in a water system using KOH and NaOH. For this study in a water system the experimental data includes individual cationic activities as well as pH values. Adsorption of the cations was adequately described over a pH range of 5-11 by the equation 1-θ/θ ⋅ aNa+ ⋅ aOH- = 1/K'3 [aOH- + KW/K'2 + 1/K'1], in which θ represents the fraction of the total sites that have reacted. Thermodynamic constants K'3 and K0= KW/K'2 + 1/K'1 of this equation were calculated. In the second group of experiments a higher pH range was attained by making the titrations with NaCC2H3 in absolute ethanol. Interpretation of this data by use of a Langmuir-type equation revealed two fairly homogeneous types of acid sites for each mineral. It was also possible to calculate the apparent equilibrium constants of the various reaction sites involved. A discussion of possible mechanisms for two acid sites on these minerals is given.
College and Department
Chemistry and Biochemistry
BYU ScholarsArchive Citation
Anderson, Kenneth H., "Acidic properties of clay minerals and alumina" (1955). Theses and Dissertations. 8154.