The effect of the nitric acid concentration on the kinetics of 2,4-dinitroaniline nitration in aqueous nitric and sulfuric acid solutions

1978 ◽  
Vol 27 (3) ◽  
pp. 478-483
Author(s):  
G. F. Burya ◽  
L. D. Abramovich ◽  
L. R. Andreeva ◽  
A. K. Eremin ◽  
M. I. Vinnik
Keyword(s):  
Sulfuric Acid ◽  
Nitric Acid ◽  
Acid Concentration ◽  
Nitric Acid Concentration ◽  
Acid Solutions ◽  
Sulfuric Acid Solutions ◽  
Kinetics Of

Kinetics of reduction of U(VI) with zinc amalgam in sulfuric acid solutions

2015 ◽  
Vol 57 (1) ◽  
pp. 31-35 ◽  
Author(s):  
V. N. Momotov ◽  
E. A. Erin ◽  
V. M. Chistyakov
Keyword(s):  
Sulfuric Acid ◽  
Acid Solutions ◽  
Zinc Amalgam ◽  
Sulfuric Acid Solutions ◽  
Kinetics Of ◽  
Kinetics Of Reduction

Selective separation of silver(I) by novel substituted thiourea

2007 ◽  
Vol 95 (8) ◽  
Author(s):  
Aslam Khan
Keyword(s):  
Experimental Data ◽  
Nitric Acid ◽  
Acid Concentration ◽  
Organic Phase ◽  
High Selectivity ◽  
Nitric Acid Concentration ◽  
Equilibration Time ◽  
Acid Solutions ◽  
Nitric Acid Solutions ◽  
Species Effect

The extraction of silver(I) from nitric acid solutions using naphthyl substituted thiourea such as 1-naphthylthiourea (ANTU) has been studied. Different variables: equilibration time, aqueous pH, chloride and extractant concentrations and organic phase diluent that could affect the extraction system were evaluated at 28.0 ± 2.0 °C. It was found that silver is quantitatively extractred by ANTU over the entire studied range of nitric acid concentration. Extraction of silver by ANTU is fast and equilibration was achieved in less than five minutes. Experimental data relating to silver have been analysed to determine the stoichiometry of the extracted species. Effect of foreign ions on the extraction of silver was carried out. Recycling capacity of the extractant was also studied. Thiourea and EDTA solutions were found suitable for > 99% stripping of extracted silver(I). The reagent has been found to have high selectivity for silver against copper, cadmium, nickle, cobalt, halfnium, zircomium and europium.

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.

Separation and purification of Th from U by ammonium molybdophosphate from nitric solutions

2002 ◽  
Vol 90 (5) ◽  
Author(s):  
A. M. I. Ali ◽  
H. G. Nowier
Keyword(s):  
Nitric Acid ◽  
Acid Concentration ◽  
Nitric Acid Concentration ◽  
Acid Solutions ◽  
Separation And Purification ◽  
Retention Capacity ◽  
Nitric Acid Solutions ◽  
Ammonium Molybdophosphate ◽  
Saturation Capacity

SummaryAmmonium molybdophosphate(AMP) was synthesized and characterized. The AMP was found to be insoluble in water or nitric acid solutions of different concentrations. The sorption of Th and U from nitric acid by AMP has been investigated. The effect of shaking time on the sorption of Th was studied. The effect of nitric acid, Th concentration and AMP on the sorption of Th were also studied. Studies on the retention capacity of AMP showed that its capacity decreased by increasing the nitric acid concentration of Th. The saturation capacity was found to be 120 mg Th/g

Anodic Polarization Behavior Of Nickel-Chromium Alloys In Sulfuric Acid Solutions

CORROSION ◽  
1965 ◽  
Vol 21 (9) ◽  
pp. 277-287 ◽  
Author(s):  
J. R. MYERS ◽  
F. H. BECK ◽  
M.G. FONTANA
Keyword(s):  
Sulfuric Acid ◽  
Critical Current Density ◽  
Critical Current ◽  
Acid Concentration ◽  
Current Density ◽  
Anodic Polarization ◽  
Chromium Content ◽  
Acid Solutions ◽  
Polarization Behavior ◽  
Sulfuric Acid Solutions

Abstract Anodic polarization behavior of annealed high-purity Ni, Cr and selected Ni-Cr alloys in hydrogen-saturated, 1, 5, 10 and 20N sulfuric acid solutions was investigated at 25 ± 1 C (77 F) using a potentiostatic technique. All specimens except pure Ni in 20N acid had an active-to-passive transition. Decreasing acid concentration increased passive potential range of pure Ni while acid concentration did not appreciably affect the passive region of pure Cr or the Ni-Cr alloys. Increasing acid concentration and decreasing chromium content increased the secondary passivation tendency in the transpassive region. No oxygen evolved in the transpassive region except for pure Ni and the higher nickel alloys. Tafel slopes for anodic dissolution, early transpassive region and oxygen evolution were determined. Corrosion potentials for pure Ni and Ni-Cr alloys containing up to 90 w/o Cr behaved as a reversible hydrogen electrode over the pH range 1.63 to −0.44. This linear relationship did not exist for the higher acid concentrations. Slope dependence for pure Cr and the 99Cr-1Ni alloy was −0.110. A minimum in critical current density versus percent Cr curves was established at 90 to 95 w/o Cr. Passivation potentials were determined. Passive current density decreased with increasing chromium content over the composition range 0 to 33 w/o Cr. It was established that increased specimen purity decreases the magnitude of critical current density and shifts corrosion and passivation potentials in the noble potential direction.

Wettability Effect on the Corrosion Kinetics of Iron Anodes in Sulfuric Acid Solutions

1988 ◽  
Vol 135 (9) ◽  
pp. 2188-2193 ◽  
Author(s):  
O. Teschke ◽  
M. U. Kleinke ◽  
F. Galembeck
Keyword(s):  
Sulfuric Acid ◽  
Acid Solutions ◽  
Corrosion Kinetics ◽  
Sulfuric Acid Solutions ◽  
Kinetics Of
Sign in / Sign up

Export Citation Format

Share Document