International Science Community Association Research Journal of Chemical Sciences 16 2 2026 06 18 Inhibitive Action of Azadirachta indica Leaves Extract on Corrosion of Mild Steel in Acetic acid Solution 11 20 EN Gupta Swaroopa Rani N. 1 Department of Chemistry, Brijlal Biyani Science College, Amravati, Maharashtra India Chaudhari Harshida G. 1 Department of Chemistry, Shree Jayendrapuri Arts and Science College, Bharuch, Gujarat, India Vashi Rajendra T. 2 Chemistry Department, Navyug Science College, Rander Road, Surat, Gujarat, India > Research Paper 2025 8 10 2026 06 18 The corrosion inhibition effect of Azadirachta indica (AZI) leaves extract on corrosion of mild steel (MS) in a acetic acid solution has been evaluated by weight loss (WL), potentiodynamic polarization (PDP) and electrochemical impendence spectroscopy (EIS) techniques. Corrosion rate (CR) increases with the increase in acid concentration. At constant inhibitor concentration, CR increases with increase in acid concentration, while inhibition efficiency (IE) decreases. The CR decreses as inhibitor concentration increases, while percentage of IE increases with inhibitor concentration. AZI showed maximum IE of 81.37% at 1.0g/L inhibitor concentration in 0.5 M acetic acid. Polarization measurements indicats that AZI can function as mixed-type of inhibitor. The negative value of free energy of adsorption (∆G°ads) and enthaly of adsorption (∆H°ads) indicated that the adsorption of inhibitor is spontenious and exothermic. The lover value of energy of activation (Ea) for the unhibited system compare to inhibited system, indicate that the inhibitors are more effective at lower temperature. The results shows that there is a good agreement between WL and elecrochemical techniques. Copyright@ International Science Community Association