Kinetic study of the reaction between Fe2+-oxalate and 2,6-dichlorophenolindophenol
Φόρτωση...
Ημερομηνία
Συγγραφείς
Karayannis, M. I.
Tzouwara-Karayanni, S. M.
Crouch, S. R.
Τίτλος Εφημερίδας
Περιοδικό ISSN
Τίτλος τόμου
Εκδότης
Περίληψη
Τύπος
Είδος δημοσίευσης σε συνέδριο
Είδος περιοδικού
peer reviewed
Είδος εκπαιδευτικού υλικού
Όνομα συνεδρίου
Όνομα περιοδικού
International Journal of Chemical Kinetics
Όνομα βιβλίου
Σειρά βιβλίου
Έκδοση βιβλίου
Συμπληρωματικός/δευτερεύων τίτλος
Περιγραφή
Ascorbic acid present in natural products is often analyzed by its reducing effect on 2,6-dichlorophenolindophenol (DCPI). In case of coexistence of Fe(II) in natural samples and if oxalic acid is used for their extraction and stabilization, a significant interference is observed. The reaction of Fe2+ with 2,6-dichlorophenolindophenol (DCPI) in acidic solutions in the presence or absence of oxalate ions was investigated. The reaction was studied with a Stopped-Flow Spectrophotometer (S.F.S) equiped with a data acquisition system, which allows the determination of initial rates and reaction rate constants. Results for the effect of the concentrations of all the reagents of the reaction are presented. During the experimental work all concentrations of the reagents were kept in such levels to make the reaction first-order in respect of DCPI. An interesting finding is, that, although Fe2+ and C2O42- ions do not react separately with DCPI (or react very slowly), they react very rapidly in mixtures and show a strong synergetic effect. The experimental data At with the mechanism of the formation of intermediates FeC2O4 and [Fe(C2O4)(2)](2-). The proposed rate law agrees with the above mechanism and the experimental results. The value k(c) = (1.6 +/- 0.2) X 10(5) M-1.s(-1) was calculated for the second-order rate constant of the reaction of FeC2O4 and DCPI. (C) 1998 John Wiley & Sons, Inc.
Περιγραφή
Λέξεις-κλειδιά
ascorbic-acid, indophenol
Θεματική κατηγορία
Παραπομπή
Σύνδεσμος
<Go to ISI>://000077151300009
http://onlinelibrary.wiley.com/store/10.1002/(SICI)1097-4601(1998)30:12<941::AID-KIN9>3.0.CO;2-%23/asset/9_ftp.pdf?v=1&t=h1gl3ij5&s=6a534d617043d5410af4c8d367e39b1a224cd74d
http://onlinelibrary.wiley.com/store/10.1002/(SICI)1097-4601(1998)30:12<941::AID-KIN9>3.0.CO;2-%23/asset/9_ftp.pdf?v=1&t=h1gl3ij5&s=6a534d617043d5410af4c8d367e39b1a224cd74d
Γλώσσα
en
Εκδίδον τμήμα/τομέας
Όνομα επιβλέποντος
Εξεταστική επιτροπή
Γενική Περιγραφή / Σχόλια
Ίδρυμα και Σχολή/Τμήμα του υποβάλλοντος
Πανεπιστήμιο Ιωαννίνων. Σχολή Θετικών Επιστημών. Τμήμα Χημείας