caa a22 4500 477139280 CHVBK 20180405111728.0 cr unu---uuuuu 170330e19970301xx s 000 0 eng 10.1007/BF02767996 doi (NATIONALLICENCE)springer-10.1007/BF02767996 Thermodynamic models for highly charged aqueous species: Solubility of Th(IV) hydrous oxide in concentrated NaHCO3 and Na2CO3 solutions [Elektronische Daten] [Andrew Felmy, Dhanpat Rai, S. Sterner, Marvin Mason, Nancy Hess, Stephen Conradson] An aqueous thermodynamic model is proposed to describe the solubility ofTh(IV) hydrous oxide in the aqueous Na+-HCO 3 - -CO 3 2- -OH--ClO 4 - -H2O system extending to high concentration at 25‡C. This model is relatively simple in that only two aqueous species are included: Th(OH)3CO 3 - and Th(CO3) 5 6- . Pitzer ion interaction parameters, Β(0) and Β(l) for Na+ with Th(CO3) 5 6- , are also determined (1.31 and 30, respectively). Reconciliation of all of the experimental solubility data for Th(IV) hydrous oxide in NaClO4 media required the introduction of a large mixing parameter for the highly charged Th(CO3) 4 - . The relatively large values required for the ion interaction parameters Β(0) and Β(l), together with commensurately large mixing terms with the bulk anionic species, resulted in considerable uncertainty in determining standard state equilibrium constants for the formation of the highly charged Th(CO3) 5 6- species. This uncertainty is a result of the large contributions from Β(0) and Β(l) to the excess solution free energy at the concentrations (0.1m) where this species becomes important. The magnitude of the mixing term implies that formation of this species depends strongly upon the bulk ionic media. X-ray absorption results, confirming the presence of the thorium pentacarbonate species in concentrated bicarbonate and carbonate solutions, are also included. Plenum Publishing Corporation, 1997 Thorium (IV) nationallicence hydrous oxides nationallicence complexation nationallicence carbonate nationallicence bicarbonate nationallicence ion-interaction nationallicence spectroscopy nationallicence Felmy Andrew Pacific Northwest National Laboratory, 99352, Richland, Washington aut Rai Dhanpat Pacific Northwest National Laboratory, 99352, Richland, Washington aut Sterner S. Pacific Northwest National Laboratory, 99352, Richland, Washington aut Mason Marvin Pacific Northwest National Laboratory, 99352, Richland, Washington aut Hess Nancy Pacific Northwest National Laboratory, 99352, Richland, Washington aut Conradson Stephen Los Alamos National Laboratory, Los Alamos, New Mexic aut Journal of Solution Chemistry Springer US 26/3(1997-03-01), 233-248 0095-9782 26:3<233 1997 26 10953 https://doi.org/10.1007/BF02767996 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF02767996 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Felmy Andrew Pacific Northwest National Laboratory, 99352, Richland, Washington aut NATIONALLICENCE 700 1- Rai Dhanpat Pacific Northwest National Laboratory, 99352, Richland, Washington aut NATIONALLICENCE 700 1- Sterner S. Pacific Northwest National Laboratory, 99352, Richland, Washington aut NATIONALLICENCE 700 1- Mason Marvin Pacific Northwest National Laboratory, 99352, Richland, Washington aut NATIONALLICENCE 700 1- Hess Nancy Pacific Northwest National Laboratory, 99352, Richland, Washington aut NATIONALLICENCE 700 1- Conradson Stephen Los Alamos National Laboratory, Los Alamos, New Mexic aut NATIONALLICENCE 773 0- Journal of Solution Chemistry Springer US 26/3(1997-03-01), 233-248 0095-9782 26:3<233 1997 26 10953 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer