Abstract : The anodic dissolution of Ni was studied in acidified chloride, sulfate, and perchlorate solutions under a variety of non-passivating conditions. The Tafel slopes at 45 deg C are approximately 0.085, 0.115, 0.12, respectively. The lower value of the Tafel slope in chloride solutions is attributed to specific adsorption. The potential of the Ni anode is independent of Ni(++) concentration under conditions for which the back reaction is negligible and no pH dependence has been found for pH of 1 to 2.5. The temperature dependence of the polarization yields an approximate value of 15 kcal/mole for the heat of activation in the chloride solution.