Pressure dependence of the dissociation of acetic, benzoic, mandelic and succinic acids at 298.15 K

TitlePressure dependence of the dissociation of acetic, benzoic, mandelic and succinic acids at 298.15 K
Publication TypeJournal Article
Year of Publication2005
AuthorsKumar, A
JournalThermochimica Acta
Volume439
Issue1-2
Pagination154-157
Date PublishedDEC
Type of ArticleArticle
ISSN0040-6031
KeywordsAcetic acid, benzoic acid, dissociation constants, high pressure, mandelic acid, succinic acid
Abstract

Dissociation constants for acetic, benzoic, mandelic and succinic acids have been measured at 298.15 K as a function of pressure up to 138.8 MPa. The spectrophotometric technique using Bromocresol Green as the optical indicator was employed up to ionic strength of 0.03 mol kg(-1) in aqueous solution. Thermodynamic dissociation constants were calculated with the Davies activity coefficient equation. The pressure dependences of the ionization constants for the weak acids can be described by the equation of Lown, Thirsk and Wynne-Jones, application of which leads to accurate partial molal volume change on ionization, Delta(V) over bar (o) and compressibility change, Delta(K) over bar (o) at 0.1 MPa. (C) 2005 Elsevier B.V. All rights reserved.

DOI10.1016/j.tca.2005.06.045
Type of Journal (Indian or Foreign)

Foreign

Impact Factor (IF)1.938
Divison category: 
Physical and Materials Chemistry