Travelling waves in the iodate–arsenous acid system

Abstract

The equations describing travelling waves in the iodate–arsenous acid reaction are discussed, with kinetics based on the Dushman–Roebuck scheme. These equations are used to show how the structure of the wave (its propagation speed and final reaction products) depends on the stoichiometry factor S₀, the initial concentration of arsenous acid relative to iodate. Different forms are seen in the ranges 0<S₀<5/2, 5/2<S₀<3 and S₀>3. An asymptotic analysis, based on a large parameter arising in the system, is undertaken. This shows that wave structures and propagation speeds are different in these three ranges of S₀.