Health & Environmental Research Online (HERO)


Print Feedback Export to File
3236290 
Journal Article 
Kinetics and mechanism of the oxidation of sulfite by chlorine dioxide in a slightly acidic medium 
Horvath, AK; Nagypal, IN 
2006 
1 
Journal of Physical Chemistry A
ISSN: 1089-5639
EISSN: 1520-5215 
110 
14 
4753-4758 
WOS:000236773100018 
The sulfite-chlorine dioxide reaction was studied by
stopped-flow method at I = 0.5 M and at 25.0 +/- 0.1 degrees C in a slightly acidic medium. The
stoichiometry was found to be 2SO(3)(2-) + 2(.)ClO(2) + H2O -> 2SO(4)(2-) + Cl- + ClO3- + 2H(+)
in (ClO2)-Cl-. excess and 6SO(3)(2-) + 2(.)ClO(2) -> S2O62- + 4SO(4)(2-) + 2Cl(-) in total
sulfite excess ([S(IV)] = [H2SO3] + [HSO3-] + [SO32-]). A nine-step model with four fitted
kinetic parameters is suggested in which the proposed adduct (SO3ClO22-)-S-. plays a significant
role. The pH-dependence of the kinetic traces indicates that SO32- reacts much faster with
(ClO2)-Cl-. than HSO3- does.