Behavior of lead electrodes in sulfuric acid solutions. II

1969 ◽  
Vol 47 (12) ◽  
pp. 2191-2196 ◽  
Author(s):  
E. Tarter ◽  
K. Ekler
Keyword(s):  
Sulfuric Acid ◽  
Acid Concentration ◽  
Discharge Rate ◽  
Acid Solutions ◽  
Stabilizing Effect ◽  
Two Factors ◽  
Passivation Time ◽  
Lead Electrodes ◽  
Sulfuric Acid Solutions

An attempt was made to clarify the question whether the variation in the length of the "first discharge plateau" with change in H2SO4 concentration was caused by a change in the efficiency of PbO2 formation or by a variation in its discharge rate. The relationships between acid concentration, "passivation time", amount of PbSO4 formed during passivation, and the quantity of PbO2 derived therefrom during charging were investigated. The amount of PbSO4 on the anode increased with a decrease in passivating acid concentration. More PbO2 was formed at lower charging acid concentrations. The higher the discharge acid concentration, the greater was its stabilizing effect on PbO2 discharge. The combination of two factors, i.e. a decrease of the amount of PbO2 formed at higher acid concentrations together with an increase in the PbO2 stability, gave rise to the maximum 10.5 N H2SO4.

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.

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

CEPA in Liquid Sulfuric Acid Increases Oleoresin Yields

1985 ◽  
Vol 9 (3) ◽  
pp. 170-173 ◽  
Author(s):  
Robert D. McReynolds ◽  
Susan V. Kossuth
Keyword(s):  
Sulfuric Acid ◽  
Acid Concentration ◽  
Sulfuric Acid Concentration ◽  
Pinus Elliottii ◽  
Slash Pine ◽  
Acid Solutions ◽  
Natural Stand ◽  
Breast Height ◽  
Longleaf Pines ◽  
Sulfuric Acid Solutions

Abstract Liquid sulfuric acid solutions of 12.5, 25.0, and 50% by weight were tested in combination with 0, 2.5, 5.0, 10.0, and 15.0% 2-chloroethylphosphonic acid (CEPA) for increasing oleoresin yield in slash (Pinus elliottii) and longleaf (P. palustris) pines. Maximum oleoresin yields of 262 g/cm diameter breast height (dbh) were obtained in 23- to 25-year-old clonal slash pines from 50% sulfuric acid plus 15% CEPA, a 20% increase over the slash pine control trees. In a natural stand of longleaf pines over 60 years old, maximum oleoresin yields of 297 g/cm dbh were obtained from 50% sulfuric acid plus 10% CEPA--a 30% increase over the longleaf pine control trees. The addition of CEPA to any sulfuric acid concentration always increased yields and increasing sulfuric acid concentrations without CEPA always increased yields. The sulfuric acid and CEPA effects were both significant but no interaction between them was detected for either slash or longleaf pines. Highly significant differences in yield were found among the clones.

THE BEHAVIOR OF LEAD ELECTRODES IN SULPHURIC ACID SOLUTIONS

1964 ◽  
Vol 42 (6) ◽  
pp. 1355-1364 ◽  
Author(s):  
K. Ekler
Keyword(s):  
Sulphuric Acid ◽  
Acid Concentration ◽  
Current Density ◽  
The Self ◽  
Acid Solutions ◽  
Time Data ◽  
Passivation Time ◽  
Lead Electrodes ◽  
Passivation Potential

Lead electrodes were anodically etched in NH2SO3H. Immersion potentials, self-passivation potentials, passivation times, PbO2/O2 potential, and the potential of the first discharge plateau were determined in H2SO4 solutions ranging from 0.5 to 20.0 N and were found to be concentration-dependent. Interruption of the anodizing current had no detectable influence on passivation time. Data obtained with the anodizing current turned on fall into three categories; those obtained with (1) short-immersion anodes, (2) anodes which had reached a hydrogen-like potential, and (3) anodes which were self-passivated before the current was switched on. An inflection in the relation between potential and time during charging was investigated. Its length was dependent upon acid concentration and current density, while its potential was +300 ± 30 mv, and seemed to correspond to the self-passivation potential. The lengths of the first and second discharge plateaus increased with the number of coulombs passed and were dependent upon acid concentration, but were identical for electrodes treated by four different methods. The hydrogen-like potential appeared to be due to the presence of PbO•PbSO4. The self-passivation potential seemed to be caused by formation of PbO.

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

Rheological Characterization of Sulfuric Acid Solutions of Poly(p-phenyleneterephthalamide)

1987 ◽  
Vol 2 (1) ◽  
pp. 28-32 ◽  
Author(s):  
B. C. Kim ◽  
S. S. Hwang ◽  
K. U. Kim
Keyword(s):  
Sulfuric Acid ◽  
Acid Solutions ◽  
Rheological Characterization ◽  
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

Separation of lanthanum(III), gadolinium(III) and ytterbium(III) from sulfuric acid solutions by using a polymer inclusion membrane

2018 ◽  
Vol 545 ◽  
pp. 259-265 ◽  
Author(s):  
Charles F. Croft ◽  
M. Inês G.S. Almeida ◽  
Robert W. Cattrall ◽  
Spas D. Kolev
Keyword(s):  
Sulfuric Acid ◽  
Acid Solutions ◽  
Inclusion Membrane ◽  
Polymer Inclusion Membrane ◽  
Sulfuric Acid Solutions
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