ISSN:
1434-1948
Keywords:
Dicarbonate ion
;
Autodissociation constant
;
Electrochemistry
;
Potentiometric titration
;
Acidity
;
Basicity
;
Anions
;
Chemistry
;
General Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The solubility of CO2 in the molten ternary eutectic mixture Li2CO3-Na2CO3-K2CO3 (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 CO2 of 1 atm and the pKd value of the carbonate melt has been evaluated to 5.37 (σ5 = 0.24) if the concentrations of the solutes are expressed in mol·L-1. This pKd 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 CO2 as C2O52- 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 CO2/C2O52- equilibrium in the carbonate melt is a slow process.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
