Study of heterogeneous equilibria in saturated solutions of some sparingly soluble 8-hydroxyquinolines.
Talanta
; 39(1): 55-62, 1992 Jan.
Article
en En
| MEDLINE
| ID: mdl-18965338
ABSTRACT
Heterogeneous equilibria in saturated aqueous solutions of 8-hydroxyquinoline (A), 2-methyl-8-hydroxyquinoline (B) and 5-chloro-8-hydroxyquinoline (C) were investigated at constant ionic strength (1M sodium chloride), at 25.0 +/- 0.1 degrees , by the application of the following methods:
the formation function method, the method of bound protons, the method of free proton sites and the solubility method. The following equilibrium constants were determined K(s1)=[H(2)A(+)]/[H(3)O(+)], K(s2)=[HA] and K(s3)=[H(3)O(+)] [A(-)]. Their mean pK values are -2.88, 2.42 and 12.09 for A, -3.27, 2.71 and 12.73 for B, and -0.34, 3.88 and 12.75 for C. In addition, the acidity constants of investigated 8-hydroxyquinolines were determined by pH-metric titrations. The values obtained for these constants were consistent with those calculated on the basis of corresponding equilibrium constants determined in heterogeneous systems.
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Colección:
01-internacional
Base de datos:
MEDLINE
Idioma:
En
Revista:
Talanta
Año:
1992
Tipo del documento:
Article
País de afiliación:
Yugoslavia