Iron reduction potential

However, in a pH = 5 medium, the catalytic process (obtained with NaN02 as the starting substrate) is no longer observed in the iron reduction-potential domain, but is relegated to the reduction potential of the first W-wave. This observation is in full agreement with the expected absence of NO and HNO2 in this medium. 

In contrast, experiments with pure NO [10, 155] at pH = 5 show that the catalytic process starts directly in the iron reduction-potential domain. We have also checked the catalytic reduction of NO at pH = 1. All these results converge to designate NO as the species electrocatalytically reduced by the present complexes throughout the pH domain evaluated. 

Figure 5.2 A Latimer diagram for the +3, +2 and 0 oxidation states of iron reduction potentials...

Enterobactin (ent), the cycHc triester of 2,3-dihydroxy-A/-benzoyl-l-serine, uses three catecholate dianions to coordinate iron. The iron(III)-enterobactin complex [62280-34-6] has extraordinary thermodynamic stabiUty. For Fe " +ent , the estimated formal stabiUty constant is 10 and the reduction potential is approximately —750 mV at pH 7 (23). Several catecholate-containing synthetic analogues of enterobactin have been investigated and found to have lesser, but still impressively large, formation constants. 

The most significant chemical property of zinc is its high reduction potential. Zinc, which is above iron in the electromotive series, displaces iron ions from solution and prevents dissolution of the iron. For this reason, zinc is used extensively in coating steel, eg, by galvanizing and in zinc dust paints, and as a sacrificial anode in protecting pipelines, ship hulls, etc. 

Red lead (Pb304) is manufactured on the 20000-tonne scale annually and is used primarily as a surface coating to prevent corrosion of iron and steel (check oxidation-reduction potentials). It is also used in the production of leaded glasses and ceramic glazes and. very substantially, as an activator, vulcanizing agent and pigment in natural and artificial rubbers and plastics. 

Table 25.2 Standard reduction potentials for iron, ruthenium and osmium in acidic aqueous solution...

Table 25.8 Reduction potentials of some iron proteins...

Reductant equivalent weights of, 847 Reduction 409 by chromium(II) salts, 409 by hydrogen sulphide, 416 by Jones reductor (zinc amalgam), 410 by liquid amalgams, 412 by silver reductor, 414 by sulphurous acid, 416 by tin(II) chloride, 415 by titanium(II[), 410 by vanadium(II), 410 see also Iron(III), reduction of Reduction potentials 66 Reference electrodes potentials, (T) 554 Relative atomic masses (T) 819 Relative error 134 mean deviation, 134... 

As mentioned previously, in [FegS4] + clusters, the three Fe(III) ions are not completely equivalent. NMR spectroscopy may allow one to locate the iron with the lowest reduction potential, as being the one characterized by the weakest magnetic couplings with the other two irons. However, this is true only if the energetic contributions due to other factors, such as electrostatic effects or solvent accessibility 93), are less important than those due to the magnetic coupling of the... 

The overall voltage generated by a standard galvanic cell is always obtained by subtracting one standard reduction potential from the other in the way that gives a positive value for E (.gH Example applies this reasoning to zinc and iron. 

In damp air, materials with standard reduction potentials less than 0.88 V oxidize spontaneously. Atmospheric O2 easily oxidizes iron and aluminum, the most important structural metals ... 

C19-0031. Tin cans are made of iron, coated with a thin film of tin. After a break occurs in the film, a tin can corrodes much more rapidly than zinc-coated iron. Using standard reduction potentials, explain this... 

While the oxidation reduction potential of the ferredoxins is —0.2 V to —0.4 V and that of the rubredoxins is about —0.05 V, a protein from the photosynthetic bacterium Chromatium has a redox potential of +0.35 V. This is the high potential iron protein, or HIPIP. 

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