Dependence of the Concentration of O(-i) On the Partial Pressures of Oxygen and Carbon-dioxide in a Molten Li2co3 + Na2co3 + K2co3 Eutectic Mixture At 973-k

The influence of the partial pressures of oxygen and carbon dioxide on the concentration of O( - 1) species in a molten ternary (Li2CO3 +Na2CO3 + K2CO3) eutectic mixture at 973 K has been investigated. The molecularity in oxygen was found to be equal to 0.5, in agreement with the formation of peroxide ions according to [GRAPHICS] The experimental molecularity in carbon dioxide ranges from - 0.2 to - 0.3, in marked disagreement with the value of - 1 predicted from the above reaction. The occurrence of a second reaction which produces another O( - 1) species is suggested. Peroxocarbonate ions CO42- are assumed to be formed according to [GRAPHICS] Values of K1 = 2.41 X 10(-8) and K2 = 2.44 X 10(-7) were determined. From K1 and data found in the literature, the autodissociation constant of carbonate ions in the molten eutectic at 973 K according to the reaction [GRAPHICS] was calculated as K3 = 10(-6.48). This value is in very good agreement with previously published data.