Two Rate constant kinetic model for the chromium(III)-EDTA complexation reaction by numerical simulations

The complexation reaction of Cr(III) ion in the presence of a large excess of EDTA does not follow a pseudo-first-order kinetics as sometimes suggested. There are two causes for the deviation from this simple behavior: the involvement of a long-lived intermediate, precluding the application of the s...

ver descrição completa

Detalhes bibliográficos
Autor: Pérez de Benito, Joaquín F.
Formato: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2017
País:España
Recursos:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repositorio:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:recercat.cat:2445/121916
Acesso em linha:https://hdl.handle.net/2445/121916
Access Level:acceso abierto
Palavra-chave:Crom
Reaccions químiques
Cinètica química
Chromium
Chemical reactions
Chemical kinetics
id ES_795428584de4e710573cf67413feb30b
oai_identifier_str oai:recercat.cat:2445/121916
network_acronym_str ES
network_name_str España
repository_id_str
spelling Two Rate constant kinetic model for the chromium(III)-EDTA complexation reaction by numerical simulationsPérez de Benito, Joaquín F.CromReaccions químiquesCinètica químicaChromiumChemical reactionsChemical kineticsThe complexation reaction of Cr(III) ion in the presence of a large excess of EDTA does not follow a pseudo-first-order kinetics as sometimes suggested. There are two causes for the deviation from this simple behavior: the involvement of a long-lived intermediate, precluding the application of the steady-state approximation, and the autoinhibition provoked by the release of hydrogen ions from the organic ligand to the medium as the final Cr(III)-EDTA violet complex is formed. Numerical simulations have allowed obtaining for each kinetic experiment the values of two rate constants, k1 (corresponding to the formation of the long-lived intermediate from the reactants) and k2 (corresponding to the formation of the final complex product from the long-lived intermediate), as well as the number of hydrogens liberated per molecule of final complex product formed (Hkin). The results indicate that k1 is associated to a fast step (Ea = 87 ± 4 kJ mol-1) and k2 to a slow step (Ea = 120 ± 2 kJ mol-1), whereas the number of hydrogen ions lies within the range 0 < Hkin < 2 in all the kinetic runs. A mechanism in accordance with the experimental data has been proposed.Wiley2018201820172018info:eu-repo/semantics/articleinfo:eu-repo/semantics/acceptedVersion48 p.application/pdfapplication/pdfhttps://hdl.handle.net/2445/121916Articles publicats en revistes (Ciència dels Materials i Química Física)reponame:Recercat. Dipósit de la Recerca de Catalunyainstname:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)InglésVersió postprint del document publicat a: https://doi.org/10.1002/kin.21070International Journal of Chemical Kinetics, 2017, vol. 49, p. 234-249https://doi.org/10.1002/kin.21070(c) Wiley, 2017info:eu-repo/semantics/openAccessoai:recercat.cat:2445/1219162026-05-29T05:05:01Z
dc.title.none.fl_str_mv Two Rate constant kinetic model for the chromium(III)-EDTA complexation reaction by numerical simulations
title Two Rate constant kinetic model for the chromium(III)-EDTA complexation reaction by numerical simulations
spellingShingle Two Rate constant kinetic model for the chromium(III)-EDTA complexation reaction by numerical simulations
Pérez de Benito, Joaquín F.
Crom
Reaccions químiques
Cinètica química
Chromium
Chemical reactions
Chemical kinetics
title_short Two Rate constant kinetic model for the chromium(III)-EDTA complexation reaction by numerical simulations
title_full Two Rate constant kinetic model for the chromium(III)-EDTA complexation reaction by numerical simulations
title_fullStr Two Rate constant kinetic model for the chromium(III)-EDTA complexation reaction by numerical simulations
title_full_unstemmed Two Rate constant kinetic model for the chromium(III)-EDTA complexation reaction by numerical simulations
title_sort Two Rate constant kinetic model for the chromium(III)-EDTA complexation reaction by numerical simulations
dc.creator.none.fl_str_mv Pérez de Benito, Joaquín F.
author Pérez de Benito, Joaquín F.
author_facet Pérez de Benito, Joaquín F.
author_role author
dc.subject.none.fl_str_mv Crom
Reaccions químiques
Cinètica química
Chromium
Chemical reactions
Chemical kinetics
topic Crom
Reaccions químiques
Cinètica química
Chromium
Chemical reactions
Chemical kinetics
description The complexation reaction of Cr(III) ion in the presence of a large excess of EDTA does not follow a pseudo-first-order kinetics as sometimes suggested. There are two causes for the deviation from this simple behavior: the involvement of a long-lived intermediate, precluding the application of the steady-state approximation, and the autoinhibition provoked by the release of hydrogen ions from the organic ligand to the medium as the final Cr(III)-EDTA violet complex is formed. Numerical simulations have allowed obtaining for each kinetic experiment the values of two rate constants, k1 (corresponding to the formation of the long-lived intermediate from the reactants) and k2 (corresponding to the formation of the final complex product from the long-lived intermediate), as well as the number of hydrogens liberated per molecule of final complex product formed (Hkin). The results indicate that k1 is associated to a fast step (Ea = 87 ± 4 kJ mol-1) and k2 to a slow step (Ea = 120 ± 2 kJ mol-1), whereas the number of hydrogen ions lies within the range 0 < Hkin < 2 in all the kinetic runs. A mechanism in accordance with the experimental data has been proposed.
publishDate 2017
dc.date.none.fl_str_mv 2017
2018
2018
2018
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/acceptedVersion
format article
status_str acceptedVersion
dc.identifier.none.fl_str_mv https://hdl.handle.net/2445/121916
url https://hdl.handle.net/2445/121916
dc.language.none.fl_str_mv Inglés
language_invalid_str_mv Inglés
dc.relation.none.fl_str_mv Versió postprint del document publicat a: https://doi.org/10.1002/kin.21070
International Journal of Chemical Kinetics, 2017, vol. 49, p. 234-249
https://doi.org/10.1002/kin.21070
dc.rights.none.fl_str_mv (c) Wiley, 2017
info:eu-repo/semantics/openAccess
rights_invalid_str_mv (c) Wiley, 2017
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv 48 p.
application/pdf
application/pdf
dc.publisher.none.fl_str_mv Wiley
publisher.none.fl_str_mv Wiley
dc.source.none.fl_str_mv Articles publicats en revistes (Ciència dels Materials i Química Física)
reponame:Recercat. Dipósit de la Recerca de Catalunya
instname:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
instname_str Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
reponame_str Recercat. Dipósit de la Recerca de Catalunya
collection Recercat. Dipósit de la Recerca de Catalunya
repository.name.fl_str_mv
repository.mail.fl_str_mv
_version_ 1869411340413566976
score 15.811543

Registos relacionados