Research Articles
Determination of protonation constants for 2-hydroxy-1-(2-hydroxy-4-sulpho-1-naphthylazo)-3-napthoic acid
Authors:
JA Liyanage ,
Department of Chemistry, University of Kelaniya, Kelaniya, LK
TK Janaratne
Department of Chemistry, University of Kelaniya, Kelaniya, LK
Abstract
Chemical speciation modelling in combination with potentiometric titration method was used to determine the protonation constants for 2-hydroxy-1-(2-hydroxy-4-sulpho-1-naphthylazo)-3-naphthoic acid, the Patton and Reeder's reagent, at 25° C in three ionic strengths of 0.1 mol dm-3, 0.01 mol dm-3 and 0.001 mol dm-3 NaNO3. Potentiometric titrations were performed and pH, titrant volume, temperature and free and total proton concentrations at each titration point were measured. Constants were determined for three of the four protonated sites and the forth one being a very low value as this site is always in the ionic form and is readily ionized in aqueous solutions.
Keywords: Patton and Reeder; Protonation constants; Potentiometric titrations; Chemical speciation modelling
DOI: 10.4038/josuk.v3i0.2737
J. Sci. Univ. Kelaniya 3 (2007) : 47-52
How to Cite:
Liyanage, J. and Janaratne, T., 2011. Determination of protonation constants for 2-hydroxy-1-(2-hydroxy-4-sulpho-1-naphthylazo)-3-napthoic acid. Journal of Science of the University of Kelaniya, 3, pp.47–52. DOI: http://doi.org/10.4038/josuk.v3i0.2737
Published on
24 Jan 2011.
Peer Reviewed
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