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Solubility and Solvation of Carbon Dioxide in the Molten Li 2 CO 3 /Na 2 CO 3 /K 2 CO 3 (43.5:31.5:25.0 mol‐%) Eutectic Mixture at 973 K I. Experimental Part
Author(s) -
Claes Paul,
Moyaux Dominique,
Peeters Daniel
Publication year - 1999
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/(sici)1099-0682(199904)1999:4<583::aid-ejic583>3.0.co;2-y
Subject(s) - solubility , chemistry , eutectic system , dissolution , solvation , ternary operation , carbon dioxide , carbonate , titration , ternary numeral system , inorganic chemistry , thermodynamics , organic chemistry , solvent , phase (matter) , physics , alloy , computer science , programming language
The solubility of CO 2 in the molten ternary eutectic mixture Li 2 CO 3 –Na 2 CO 3 –K 2 CO 3 (43.5, 31.5, 25.0 mol.%) at 973 K has been determined by a titration technique. From the obtained titration curve, the solubility has been found to amount to 9.5·10 −2 mol·L −1 (σ= 1.0) under a pressure of CO 2 of 1 atm and the p K d value of the carbonate melt has been evaluated to 5.37 (σ 5 = 0.24) if the concentrations of the solutes are expressed in mol·L −1 . This p K d value is in good agreement with literature data but the solubility value reported in this work is much higher than most of those reported in the literature. A chemical dissolution of CO 2 as C 2 O 5 2– is proposed and the consequences of the occurrence of this species on the acidobasic properties of molten carbonates are discussed. It appears from the experimental results that the CO 2 /C 2 O 5 2– equilibrium in the carbonate melt is a slow process.