Activities and Free Energy of Mixing of Sulfuric Acid Solutions by Gibbs–Duhem Equation Integration

2012 ◽  
Vol 57 (6) ◽  
pp. 1665-1671 ◽  
Author(s):  
Anu K. K. Lokkiluoto ◽  
Michael M. Gasik
Keyword(s):  
Free Energy ◽  
Sulfuric Acid ◽  
Acid Solutions ◽  
Duhem Equation ◽  
Energy Of Mixing ◽  
Free Energy Of Mixing ◽  
Sulfuric Acid Solutions

Inhibition of corrosion of copper in acids by norfloxacin

2017 ◽  
Vol 64 (1) ◽  
pp. 92-102 ◽  
Author(s):  
Thanapackiam P. ◽  
Kumaravel Mallaiya ◽  
Rameshkumar S. ◽  
Subramanian S.S.
Keyword(s):  
Free Energy ◽  
Sulfuric Acid ◽  
Nitric Acid ◽  
Metal Surface ◽  
Inhibition Efficiency ◽  
Acid Solutions ◽  
Free Energy Of Adsorption ◽  
Acid Media ◽  
Content Type ◽  
Sulfuric Acid Solutions

Purpose This paper aims to evaluate the inhibition efficiency of norfloxacin on the corrosion of copper in 1.0 M nitric acid and 0.5 M sulfuric acid solutions. Design/methodology/approach Evaluation was carried out by electrochemical techniques such as electrochemical impedance spectroscopy and potentiodynamic polarization studies. Scanning electron microscopy was used, and it finally confirmed the existence of the adsorbed film. Findings The electrochemical measurements showed that norfloxacin has good inhibition efficiency on the corrosion of copper in 1.0 M nitric acid and 0.5 M sulfuric acid solutions. The inhibition action of norfloxacin in both of the corrosive media was observed to be of mixed type but with more of cathodic nature. The temperature dependence of the corrosion rate was studied in the temperature range from 35 to 55°C and the activation energy (Ea) was calculated. The adsorption of norfloxacin molecules on copper surface obeyed Langmuir adsorption isotherm. Studies on the potential of zero charge have been carried out to establish the mechanism of adsorption of the inhibitor onto the metal surface. The thermodynamic parameters such as the adsorption equilibrium constant (Kads) and the free energy of adsorption (ΔGads) were calculated. The value of free energy of adsorption very close to −40 kJmol−1 indicates that the adsorption is through electrostatic coulombic attraction and chemisorption. The decrease in value of Ea with the addition of inhibitor also shows the chemisorption of the inhibitor on the metal surface. Originality/value This paper indicates that norfloxacin can act as a good inhibitor for the corrosion of copper in both the acid media.

Protection features of chromium-nickel steel in sulfuric acid solutions by triazole derivative

2019 ◽  
pp. 15-21
Author(s):  
Ya.G. Avdeev ◽  
◽  
Yu.B. Makarychev ◽  
D.S. Kuznetsov ◽  
L.P. Kazanskii ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Nickel Steel ◽  
Acid Solutions ◽  
Triazole Derivative ◽  
Sulfuric Acid Solutions

Electrochemistry of Gold in Aqueous Sulfuric Acid Solutions under Neural Stimulation Conditions

2005 ◽  
Vol 152 (7) ◽  
pp. E212 ◽  
Author(s):  
Daniel R. Merrill ◽  
Ionel C. Stefan ◽  
Daniel A. Scherson ◽  
J. Thomas Mortimer
Keyword(s):  
Sulfuric Acid ◽  
Neural Stimulation ◽  
Acid Solutions ◽  
Aqueous Sulfuric Acid ◽  
Sulfuric Acid Solutions

EXTRACTION OF AMERICIUM (IV) BY DIOCTYLAMINE PROM SULFURIC ACID SOLUTIONS CONTAINING A COMPLETING AGENT

1985 ◽  
Vol 3 (4) ◽  
pp. 417-426 ◽  
Author(s):  
B.F. Myasoedov ◽  
M.S. Milyukova ◽  
D.A. Malikov ◽  
Ye.V. Kuzovkina ◽  
N.S. Varezhkina
Keyword(s):  
Sulfuric Acid ◽  
Acid Solutions ◽  
Sulfuric Acid Solutions
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