An improved chemical model for the quantitative description of the front propagation in the tetrathionate-chlorite reaction.

It is experimentally proven that the stoichiometry of the tetrathionate-chlorite reaction is 2S4O(2-)6 + 8(1/2)ClO-(2) + 6H2O = 8SO(2-)4 + ClO-(3) + 7(1/2)Cl- + 12H+ near 1:4 molar ratio of the reactants. Re-evaluation of the previously measured front velocity--concentration curves also shows that this stoichiometry along with both the rate equation r = (1.6 x 10(5) M(-3) s(-1) [H+]2 + 3.6 x 10(7) M(-4) s(-1) [H+]3)[S4O(2-)6][ClO-(2)] and the protonation processes existing in the present system allow us to describe the front velocity as a function of the initial concentration of the reactants quantitatively. Some consequences detailed in the conclusions may concern not only uniquely the tetrathionate-chlorite reaction but any front propagation study including H+ as an autocatalyst.