Corrosion of aluminum in Hydrochloric acid and its inhibition

Present study was carried out to evaluate on corrosion loss of Zinc metal in various concentration of Nitric acid and for the protection of zinc metal author used aromatic amines (Toludines, Nitroanilines, Chloroanilines) and aliphatic amines (Ethanolamines, Ethylamines). The corrosion loss of zinc increases with increase in all acid concentration. The corrosion loss is affected by the presence of diffusion oxygen, nature of complex reaction taking place and also the nature of protective film. Inhibition Efficiency was increased in all aromatic amines studied at all inhibitor of inhibitors with increase in acid. In all types of aromatic amines o-chloro aniline, m- nitroaniline are proved an excellent inhibitor. In all aliphatic amines ethanolamine is proved an excellent inhibitor in all acid. Thermodynamics parameters like Energy of activation (Ea), Free energy of adsorption (ΔG°a), Heat of adsorption (Qads), Enthalpy (ΔH) and Entropy (ΔS) are also studied. Tafel slope in presence of inhibitors indicate their effect on both anodic and cathodic process during the corrosion of zinc in nitric acid.