Investigation of Heteropoly Niobotungstolanthanidate Ions Equilibria in the Aqueous Solutions at Different Ionic Strengths

• Autorzy: Rozantsev G. , Radio S. , Kozlova T.
• Języki publikacji: EN

Abstrakty

EN

The condensation process in the system: Ln3+-H3Nb6O19 5 -WO4 2 -OH-(H+)-H2O (Ln = Ho, Nd; ni(Nb):ni(W) = 9:1) has been investigated. According to the results of potentiometric titrations, the model of the condensation process has been proposed. Diagrams of mixed heteropoly niobotungstolanthanidate anions (HPNTLA) distribution within an intervals ZH+ = [ni(H+ )]/[ni(W) + ni(Nb)] = 0.00÷0.30 and ZOH- = [_(OH-)]/[ni(W) + ni(Nb)] = 0.00÷0.36 have been drawn. It has been shown that at Z H+ > 0.30 there occurs a destruction of heteropolyanions (HPA). Concentration and thermodynamic constants of HPA formation have been determined. Existence of HPNTLA has been confirmed by chemical and IR-spectroscopic analyses of Tl6H4[HoNb9W(OH)8O28]ni4.0H2O, which was isolated from a solution with Z H+ = 0.08. It has also been shown, that HPNTLAkeeps the ratio of Nb:W = 9:1 within the entire interval ZOH-. The main destruction phases of Tl6H4[HoNb9W(OH)8O28]x4.0H2O have been determined by X-ray powder diffraction analysis.

Słowa kluczowe

EN

heteropoly niobotungstolanthanidate; ionic equilibrium; thermodynamic constants; holmium; neodymium

• Wydawca: Polskie Towarzystwo Chemiczne
• Czasopismo: Polish Journal of Chemistry
• Rocznik: 2006
• Tom: Vol. 80, nr 2
• Strony: 235--245
• Opis fizyczny: Bibliogr. 14 poz.

Twórcy

autor

Rozantsev G.

autor

Radio S.

autor

Kozlova T.

• Department of Inorganic Chemistry, Donetsk National University,Universitetskaya str., 24, Donetsk 83055, Ukraine

Bibliografia

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