A new corrosion inhibitor namely 2-[Bis-(3,5-dimethyl-pyrazol-1-ylmethyl)-amino]-3-hydroxy-butyric acid (Bip2) has been synthesized and its inhibitive performance towards the corrosion of carbon steel in 1.0 M hydrochloric acid has been investigated. Corrosion inhibition was studied by chemical method (weight loss) and electrochemical techniques include Tafel extrapolation method and electrochemical impedance spectroscopy (EIS). The efficiency of the inhibitor increases with increase in the inhibitor concentration. Results obtained reveal that the used Bipyrazole derivative performs as corrosion inhibitor for carbon steel in 1.0 M HCl. Double layer capacitance, Cdl, and charge transform resistance, Rct values were derived from Nyquist plots obtained from A.C. impedance studies. Changes in impedance parameters are indicative of the adsorption of this inhibitor on the steel surface. Polarisation studies showed that Bip2 was mixed-type inhibitor in 1.0 M HCl. The values of the inhibition efficiency calculated from the three techniques are in reasonably good agreement. The adsorption of this compound on carbon steel surface is found to obey Langmuir adsorption isotherm.
