Picralima nitidaleaf in 1.0M HCl has been subjected to seriesof investigationsusinggravimetricmethod(weightloss),potentiodynamic polarization and electrochemical impedance spectroscopy techniques, the inhibitor concentrations involved 0.2, 0.45, 0.7, 0.95, 1.0, 1.2  at temperature range of 303, 313 and 323k. The study revealed that PNL has been proved to be highly effective as corrosion protection of mild steel by reaching its optimum inhibition efficiency of 88.54%, at 303k and concentration of 1.2g/L. The adsorption behavior of the inhibitor for mild steel/solution surface studied showed that Langmuir isotherm model is found most suitable than Temkin, Flory-Huggins and Frumkin when all were tested. Physisorption of the molecules of inhibitor over mild steel surface is found accountable for corrosion inhibition of mild steel in acidic medium.

mild steel, corrosion inhibitor, acidic medium, Picralima nitida, potentiodynamic.