Other Redox Reactions

The oxidation kinetics of // fl i -aquabis(ethylenediamine)isothiocyanatocobalt(iii) ion with peroxodisulphate have been investigated in 0.01 M-HC104. The reaction products /rfl 5-[Co(OH2)(en)2CN]2+ and rran5-[Co(OH2)(en)2NH3]= + were identified by ion-exchange procedures. The rate law may be expressed as 

The variation of rate constant with ionic strength was measured and values of ZaZb of —2.00 in accord with a transition state involving the reactants were observed when the distance of closest approach of the reactants was 0.5 nm. Comparison of the present data with those for oxidation of free thiocyanate shows the latter to have a lower activation energy (12 compared with 15 kcal mol ) but amore negative activation entropy (-32 compared with —18.5 cal mol ). 

The reactions of thiocyanate with [Os(bipy)3] + and [Os(phen)3] + have been studied. The rate law derived is of the form 

Volarova and V. Holba, Coll. Czech. Chem. Comm., 1979, 44, 1052. 

The osmium(viii)-catalysed oxidation of Te v by [M(CN)8] has been studied in alkaline media (M=Mo or W), the reactions being first order in both [octa-cyanometallate] and catalyst. The overall stoicheiometry is 

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Redox Electrodes Electrodes of the first and second kind develop a potential as the result of a redox reaction in which the metallic electrode undergoes a change in its oxidation state. Metallic electrodes also can serve simply as a source of, or a sink for, electrons in other redox reactions. Such electrodes are called redox electrodes. The Pt cathode in Example 11.1 is an example of a redox electrode because its potential is determined by the concentrations of Ee + and Ee + in the indicator half-cell. Note that the potential of a redox electrode generally responds to the concentration of more than one ion, limiting their usefulness for direct potentiometry. 

More detailed consideration of these various equilibria and other redox reactions of the halogen oxoacids will be found under the separate headings below. As expected, the rates of redox reactions of the halogen oxyanions will depend, sometimes crucially, on the precise conditions used. However, as a very broad generalization, they tend to become progressively faster as the oxidation state of the halogen decreases, i.e. ... 

From what we know today about PET in biological and synthetic membrane or layered systems, we may expect that the non-biological apparatus providing photogeneration of spatially separated one-electron reductant and oxidant is likely to be developed in a rather universal way and may be expected to accomplish in the future not only water cleavage, but also various other redox reactions, such e.g., as photochemical synthesis of ammonia via the hv... 

Zinc peroxide Alone, or Metals See other redox reactions... 

See other REDOX REACTIONS See related ALKYL HYDROPEROXIDES... 

The base was being prepared by distilling a mixture of hydroxylamine hydrochloride and sodium hydroxide in methanol under reduced pressure, and a violent explosion occurred towards the end of distillation [1], probably owing to an increase in pressure above 53 mbar. It explodes when heated under atmospheric pressure [2], Traces of hydroxylamine remaining after reaction with acetonitrile to form acetamide oxime caused an explosion during evaporation of solvent. Traces can be removed by treatment with diacetyl monoxime and ammoniacal nickel sulfate, forming nickel dimethylglyoxime [3], An account of an extremely violent explosion towards the end of vacuum distillation had been published previously [4], Anhydrous hydroxylamine is usually stored at 10°C to prevent internal oxidation-reduction reactions which occur at ambient temperature [5], See other REDOX REACTIONS... 

See METAL THIOCYANATES Oxidants, MOLTEN SALT BATHS See other REDOX REACTIONS... 

Other redox reactions can also occur in such mixtures, and some can lead to the formation of O2 and the regeneration of Fe2+ ... 

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