ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Source of the bromide ions in the oscillation reaction of the Belousov-Zhabotinskii type with D-glucose

P. Ševčík and O. Guráňová

Department of Physical Chemistry, Faculty of Natural Sciences, Comenius University, CS-842 15 Bratislava

Abstract: The redox reaction between the bromate ions and D-glucose is autocatalytic in homogeneous medium. Provided the bubbling with nitrogen is sufficient, it is a first-order reaction with respect to both reactants and k=2.02 x 10^-3 dm³ rnol^-1 s^-1 in 1 M-H₂S0₄ at 25 °C. For an aqueous solu­tion of bromine and D-glucose the oxidizing particle is the bromine molecule and the two-electron reaction pathway through HOBr is relatively unimpor­tant for production of the Br^- ions. The reaction of Br₂ with D-glucose is light-sensitive and in dark it is a first-order reaction with respect to both reactants while it holds к = 5.57 x 10^-4 dm³ mol^-1 s" 1 in 1 M-H₂S0₄ at 25 °C. There are indications that the bromine atoms are precursor of the bromide ions in the investigated system.

Full paper in Portable Document Format: 444a467.pdf

Chemical Papers 44 (4) 467–475 (1990)