Synergistic Effect of Cl-, Br- and I- on the Corrosion Inhibition of Mild Steel in H2SO4 by a Resorcinol:Kinetics and Thermodynamic Studies

The synergistic effect between resorcinol and halides on the corrosion of mild steel in 0.5 M H2SO4 solution at 298K is done by mass loss method. Experimental results revealed the pointing synergistic activity of halides on the protective effect of resorcinol. The effect of halides on the inhibition efficiency obey the trend: Cl^- < Br^- < I^-. This trend shows that the radii and electronegativity of the halide play a predominant role in the adsorption process. In contrary the synergism obey the opposite order due to the effective inhibition efficiency of iodide. The adsorption of the resorcinol follows the Langmuir adsorption isotherm. Some kinetic and thermodynamic parameters also calculated and discussed.