Polarization and impedance measurements in a corrosive environment have been used to investigate the adsorption and corrosion inhibition characteristics of sodium dodecanoate on lead. Results show that the concentration of sodium dodecanoate has an important effect on the anodic lead dissolution. Monolayer adsorption occurs at low inhibitor concentrations. The equilibrium constant (K-ads), calculated using the Frumkin model, is about 10(-5) M-1. Multilayer formation at concentrations above the critical micelle concentration ensures the formation of a lead dodecanoate coating following the dissolution-precipitation mechanism. These lead complexes are formed on top of the surface, which has been confirmed by secondary electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS) and X-ray photoelectron spectroscopy (XPS). (C) 2014 The Electrochemical Society. All rights reserved.