Volume No. 3 Issue No.: 1 Page No.: 97-104 July-Sept 2008

 

NITRO ANILINE AS CORROSION INHIBITOR FOR ZINC IN NITRIC ACID

 

R.T. Vashi*1, S.A. Desai and P.S. Desai2

1. Department of Chemistry, Navyug Science College, Surat (INDIA)
2. Department of Bio Chemistry, B. M .College of Biotechnology, Bharthana, Surat (INDIA)

 

Received on : March 5, 2008

 

ABSTRACT

 

The corrosion of zinc in nitric acid containing nitro aniline has been studied at different acid concentration, inhibitor concentration and temperature. In acid, corrosion increases with concentration of acid and with temperature. At constant acid concentration, the inhibition efficiency (I.E.) of nitro anilines increases with concentration. At constant inhibitor concentration, the I.E. increases with the concentration of acid. At 40 mM inhibitor concentration in 0.15 M HNO3 acid at 301 K for 24 h immersion period, the I.E. decrease in the order: m-nitro aniline (99.4%) > p- nitro aniline (97.9%) > o- nitro aniline (90.8 %). The mode of inhibition action appears to be chemisorption since the plot of log (?/1-?) versus log C gives straight line which suggest that the inhibitors cover both the anodic and cathodic regions through general adsorption following the Langmuir isotherm. Anodic and cathodic galvanostatic polarization curves show little anodic but significant cathodic polarization.

 

Keywords : Corrosion, Zinc, Nitric acid, Nitro aniline, Polarization.

 

 

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