Influence of tetrabutylammonium bromide and sodium bromide on acid-base properties of thymol blue in water-ethanol medium
Abstract
For the first time the values of two acidity constants Ka1 and Ka2 of the sulfophthalein indicator thymol blue in water and water-ethanol (mass fraction of ethanol is 50%) solutions with and without addition of tetrabutylammonium bromide and a background electrolyte NaBr were determined. Spectrophotometry was chosen as a method of investigation and potentiometry was used to check the pH value in the solutions. It was found that the influence of tetrabutylammonium bromide on the pKa2 values (compared with aqueous solutions) of thymol blue in water and water-ethanol solutions correlated in sign with the effects that took place in micellar solutions of cationic surfactants for this indicator. Changes in the pKa1 value did not exceed a measurement error.
Downloads
References
Mchedlov-Petrosyan N.O. Differentiation of the strength of organic acids in true and organ-ized solutions / N.O. Mchedlov-Petrosyan. – Kharkov: Kharkov University Press, 2004. – 326 p.
Mchedlov-Petrossyan N.O. Effect of salts on the ionization of indicators in the Stern layer of cationic micelles / N.O. Mchedlov-Petrosyan, L.P. Loginova, V.N. Kleshchevnikova // Zhurn. Fiz. Khim. – 1993. – Т. 67, №8. – С. 1649-1653. [in Russian]
Mchedlov-Petrossyan N.O. Influence of the cetyltrimethylammonium chloride micellar pseu-dophase on the protolytic equilibria of jxyxanthene dyes at high bulk phase ionic strength / N.O. Mchedlov-Petrossyan, V.N. Kleshchevnikova // J. Chem. Soc. Faraday Trans. – 1994. – Vol. 90, N. 4. – P. 629–640.
The influence of 1-butanol and electrolytic background on the properties of CTAB micelles as examined using a set of indicator dyes / N.N. Kamneva, A.Yu. Kharchenko, O.S. Bykova, A.V. Sundenko, N.O. Mchedlov-Petrossyan // Journal of Molecular Liquids. – 2014. – Vol. 199. – p. 376-384.
Funasaki N. Micellar effects on the kinetics and equilibrium of chemical reactions in salt solu-tions / Funasaki N. // J. Phys. Chem. – 1979. – Vol. 83, N. 15. – Р. 1998-2003.
The influence of the micellar pseudophase of the double-chained cationic surfactant di-n-tetradecyldimethylammonium bromide on the absorption spectra and protolytic equilibrium of indicator dyes / N.O. Mchedlov-Petrossyan, N.N. Kamneva, A.Yu. Kharchenko [et al.] // Colloids and Surfaces A: Physicochemical and Engineering Aspects – 2015. – Vol. 476. – p. 57-67.
Mchedlov-Petrossyan N.O. Protolytic equilibrium in lyophilic nanosized dispersions: Differ-entiating influence of the pseudophase and salt effects / N.O. Mchedlov-Petrossyan // Pure Appl. Chem. – 2008. – Vol. 80, N. 7. – P. 1459–1510.
Protolytic and Complexing Properties of Indicators in the Gelatin Gel Medium / E.A. Reshetnyak, N.A. Nikitina, L.P. Loginova, N.O. Mchedlov-Petrossyan, N.V. Svetlova // Kharkov University Bulletin. – 2005. – No. 669. Chemical Series. Issue 13(36). – P. 67–82. [In Russian]
Indikatornye sistemy / V.M. Ostrovskaya, O.A. Zaporozhets, G.K. Budnikov, N.M. Chernyavskaya. – 2002, Moscow: Viniti RAN. – 256 p. [In Russian]
Bulatov M.I. Prakticheskoe rukovodstvo po fotometricheskim metodam analiza / M.I. Bulatov, I.P. Kalinkin. – 1986, Leningrad: Khimiya. – 432 p. [In Russian]
Bishop E. Indicators / E. Bishop. – 1972, New York: Pergamon Press. – 756 p.
Aleksandrov V.V. Kislotnost’ nevonykh rasvorov / V.V. Aleksandrov. – 1981, Kharkov: Kharkov University Press. — 152 p. [In Russian]
Bell R.P. Indicator measurements with amines in anisole and chlorobenzene solution / R.P. Bell, J.W. Bayles // J. Chem. Soc. — 1952. — P. 1518–1524.
