The propagation of arsenous acid-iodate reaction fronts of different net stoichiometries in externally applied de electric fields is studied for a range of both electric field intensities and initial compositions of the reacting mixture (represented by the stoichiometric factor S-0). Regions of three different types of net stoichiometry in the parametric space E/V vs S-0, where E is the intensity of the applied electric field and V the reaction front propagation Velocity, are determined both experimentally and by analyzing a reaction-diffusion-migration model that includes a realistic kinetic scheme of the reaction studied. Both agreement with and discrepancies between the theoretical predictions and experimental findings are discussed.