The enthalpy and entropy of activation for ethyl acetate saponification
Article first published online: 24 JAN 2012
Copyright © 2012 Wiley Periodicals, Inc.
International Journal of Chemical Kinetics
Volume 44, Issue 10, pages 692–698, October 2012
How to Cite
Petek, A. and Krajnc, M. (2012), The enthalpy and entropy of activation for ethyl acetate saponification. Int. J. Chem. Kinet., 44: 692–698. doi: 10.1002/kin.20712
- Issue published online: 24 AUG 2012
- Article first published online: 24 JAN 2012
- Manuscript Accepted: 10 DEC 2011
- Manuscript Revised: 3 NOV 2011
- Manuscript Received: 25 JUL 2011
The saponification of ethyl acetate was measured by conductimetry at different temperatures within a batch reactor. A new mathematical model for obtaining concentration profiles from conductivity was presented and used for reaction-kinetics' determination. The Arrhenius parameters (A, Ea) showed good agreement with the previously published values. Basic transition-state theory was used for obtaining the Gibbs energy (ΔG‡), the enthalpy (ΔH‡), and the entropy (ΔS‡) of activation. The low enthalpy of activation and negative entropy of activation were consistent with a reaction pathway when forming a transition-state complex. The suggested mechanism involves OH−, acting as a general base for removing proton from one of the hydroxide hydrating water, placed directly between it and the ester. The nucleophile from the water then attacks at the electrophilic C of the ester, breaking the π bond, and creating a tetrahedral intermediate. © 2012 Wiley Periodicals, Inc. Int J Chem Kinet 44: 692–698, 2012
This article was published online on 24 January 2012. An error was subsequently identified. This notice is included in the online and print versions to indicate that both have been corrected on 16 July 2012.