A Contribution to the Estimation of Binary Halide and Pseudo-Halide Equilibrium Constants using a Linear Extrapolation Methodology
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Data
2010-01-01
Autores
Silva, Astrea F. de S.
Ortega, Manuel M.
Melios, Cristo B. [UNESP]
Pezza, Leonardo [UNESP]
de Moraes, Mercedes [UNESP]
Tenan, Mario Alberto
Oliveira, Andre F.
Título da Revista
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Título de Volume
Editor
Soc Brasileira Quimica
Resumo
The molar single ion activity coefficient (y(F)) of fluoride ions was determined at 25 degrees C and ionic strengths between 0.100 and 3.00 mol L(-1) NaClO(4) using an ion-selective electrode. The activity coefficient dependency on ionic strength was determined to be Phi(F) = log y(F) = 0.2315I-0.041I(2). The function Phi(F)(I), combined with functions obtained in previous work for copper (Phi(Cu)) and hydrogen (Phi(H)), allowed us to make the estimation of the stoichiometric and thermodynamic protonation constants of some halides and pseudo-halides as well as the formation constants of some pseudo-halides and fluoride 1:1 bivalent cation complexes. The calculation procedure proposed in this paper is consistent with critically-selected experimental data. It was demonstrated that it is possible to use Phi(F)(I) for predicting the thermodynamic equilibrium parameters independently of Pearson's hardness of acids and bases.
Descrição
Palavras-chave
thermodynamic activity, ion-selective electrode analysis, stability constants
Como citar
Journal of The Brazilian Chemical Society. São Paulo: Soc Brasileira Quimica, v. 21, n. 1, p. 135-U58, 2010.