Anodic dissolution of iron in chloride solutions. The effect of pH

The anodic behavior of iron in chloride solutions is studied in a wide rang e of pH values. A break of the continuity of the logj(a)-pH dependence in t he pH range from 3 to 4 is proved. The break is accompanied by a change in the order of the anodic reaction in hydroxide ions from a positive value to zero. The conventional kinetic schemes of the anodic dissolution of iron a re shown to be insufficient for the explanation of the observed phenomenon. An interpretation based on the ideas on the effect of the composition of b oth solution and metal surface on the structure of the electrolyte layer ne xt to the electrode is proposed. It is shown that, for explaining the whole scope of experimental data, one should take into account the consistent (c ooperative) effects of the components of the solution on the anodic process .