Olasehinde, Emmanuel F.Olusegun, S. J.Adesina, A. S.Omogbehin, S. A.Momoh, Yahayah H.2019-06-262019-06-262012-06Olasehinde, E. F., Olusegun, S. J., Adesina, A. S., Omogbehin, S. A., & Momoh-Yahayah, H. (2013). Inhibitory action of Nicotiana tabacum extracts on the corrosion of mild steel in HCl: adsorption and thermodynamics study. Nat. Sci, 11(1), 83-90.1545-0740http://repository.elizadeuniversity.edu.ng/jspui/handle/20.500.12398/171The toxic effects of synthetic corrosion inhibitors have led to the search for naturally occurring substances which are not only readily available but are also environmentally friendly. Therefore, this study investigates the inhibition efficacy of acid extract of Nicotiana tabacum leaves on mild steel in 1M HCl using weight loss method. Experiments are performed by varying immersion period, concentration of the inhibitor and temperature. The inhibition efficiency is markedly higher on the addition of Nicotiana tabacum leaves extract in acidic medium compared with those in the absence of inhibitor. The inhibition efficiency increased with an increase in inhibitor concentration but decreased with rise in temperature and exposure time. Thermodynamic studies revealed that corrosion inhibition may be due to the spontaneous physical adsorption of the plant constituents on the surface of mild steel. Experimental data fitted with the Langmuir and Temkin adsorption isotherms. Kinetic treatment of the data followed a first order reaction. Calculated half-lives increase as the concentration of the extracts increases suggesting that inhibition efficiency increases with increase in the concentration of the extracts.Preliminary investigation of the phytochemical constituents showed that Nicotiana tabacum contains tannin,flavonoid, terpenoid and some other compounds in trace constituents. [Olasehinde, EF, Olusegun, SJ, Adesina, AS, Omogbehin, SA, Momoh-Yahayah, H. Inhibitory Action of Nicotiana tabacum Extracts on the Corrosion of Mild Steel in HCl: Adsorption and Thermodynamics StudyenSteel CorrosionInhibitionNicotiana tabacumThermodynamicKineticsAdsorptionArticle