HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Essington, M. E. Search for Related Content PubMed Articles by Essington, M. E. Agricola Articles by Essington, M. E.

Solubility of Barium Arsenate

Division of Waste Characterization and Chemistry, Western Res. Inst., Univ. of Wyoming Res. Corp., P.O. Box 3395, Laramie, WY 82071

*Corresponding author.

ABSTRACT

Current thermodynamic data suggest barium arsenate [Ba₃(AsO₄)₂(c)] to be a highly stable phase. However, sufficient evidence is available to question the validity of the current data. In order to determine the solubility (pK_sp) and calculate the standard free energy of formation (G°_f) of Ba₃(AsO₄)₂(c), an equilbrium solubility study was conducted. The equilibrium experiments were carried out under three different ionic strength conditions for reaction times up to 45 d. Equilibrium was approached from both undersaturated and supersaturated initial conditions. The pK_sp for the dissolution of Ba₃(AsO₄)₂(c) was calculated to be 21.62. Correspondingly, a G°_f of – 3101.2 ± 2.0 kJ mol^–1 was calculated. This value is 166.9 kJ mol^–1 more positive than the current literature value. Reevaluation of the solubility data from a previous work suggests that the pK_sp for the dissolution of BaHAsO₄ · H₂O(c) is 24.64 and the corresponding G°_f is – 1587.0 ± 2.5 kJ mol^–1.

Contribution of the Division of Waste Characterization and Chemistry. Support by the U.S. Dep. of Energy, as part of Cooperative Agreement no. DE-FC21-86MC11076, is gratefully acknowledged.

Received for publication January 25, 1988.

This article has been cited by other articles:

				R. B. Johnston and P. C. Singer Solubility of Symplesite (Ferrous Arsenate): Implications for Reduced Groundwaters and Other Geochemical Environments Soil Sci. Soc. Am. J., January 1, 2007; 71(1): 101 - 107. [Abstract] [Full Text] [PDF]