The standard rate constant of the exchange Sb(III) + 3e ⇌ Sb(Hg)

Determination of chemical reaction rate constants preceding or following electron transfer by mechanical square wave polarography

“…We determined the charge transfer rate constant of Sb(III) in various electrolytes (see Table III). The results are in agreement with the values obtained by Moussa and co-workers (10). The charge transfer rate constant of Sb(III) in 4 M NaCl (pH 1.1) is 8.3 X 1(T2 cm/s; thus, the reduction process of Sb(III) is reversible for ordinary polarography, but it is a quasi-reversible electrode process for square wave polarography.…”

“…If the potential of DME is at peak potential, and D0x = DRed = D, the following expression can be obtained from the solutions of the differential equations for the EC process on DME: (10) in which Co/, Coxb is the concentration of Ox at the surface of DME and in the bulk solution, respectively, and…”

“…Organic matter in seawater has been found to complex trace metals, especially copper (6)(7)(8). Equilibrium models including organic ligands in fresh and salt water generally employ known complexing ligands (9), make assumptions on the range that the metal-organic ligand stability constant might be, or infer what the stability constant would have to be in order for it to successfully compete with inorganic ligands in a speciation model (10). Determinations of stability constants in fresh and coastal waters have generally concluded that metal-organic ligand stability constants are in the range of 106 and 1010 (11) and, therefore, that bulk organic matter is not important in the speciation of trace metals in these waters.…”

“…The work of Everhart and Reilley (10) and that of others (17) further suggests that degradation of organic species in the spectrometer is catalyzed by the presence of sodium. In the electrochemical systems described here, adsorption of the various dithizone forms takes place from sodium hydroxide based pH 12 buffer solutions.…”

“…Everhart and Reilley have previously noted decomposition of organic species in the DuPont 650B spectrometer. They theorize that decomposition is initiated by what resembles a low-pressure plasma established above the sample which is a result of the high secondary electron flux characteristic of the DuPont spectrometer (10). Not only would such a lowpressure plasma provide the necessary perturbation for decomposition of surface dithizone species in these systems, but it would also provide the energy necessary for the formation of the respective nitrides from the metals and the decomposition products.…”