The interaction of cobalt cations with orthotungstate anions at Z=1,00.

Abstract

In the master`s work the interactions in aqueous solution of the system Co²⁺–WO₄^2–– H⁺(Z = 1,00) – H₂O are studied by pH-potentiometric titration method, the mathematical modeling is done in the program CLINP 2.1. The model, which consist ion pairs [Cо²⁺, W₁₂O₄₀ (OH) ₂] ^8- [Co²⁺, HW₁₂O₄₀ (OH) ₂] 7- , [Co²⁺, H₂W₁₂O₄₀ (OH) ₂] ^6-, [Co²⁺, H₃W₁₂O₄₀ (OH) ₂] ^6-, is selected as an experiment adequate one. The concentration constants logarithms of the anions formation, which are obtained by the modeling, are used to calculate the thermodynamic constants logarithms by the Pitzer method. The sodium-cobalt double paratungstate B Na₄Co₃[W₁₂O₄₀ (OH) ₂]·24,5H₂O is obtained by the acidity Z = 1,00. The single phase and the composition of the salt are studied by methods of chemical analysis and scanning electron microscopy. The presence of paratungstate B-anion in the salt composition is shown by IR spectroscopy method.