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Polarographic behavior of 2,4-dinitrobenzene and products of its reduction, 2-chloro-5-nitroaniline and 4-chloro-3-nitroaniline, is studied: it is shown that formation of the corresponding chloronitroanilines in the case of polarographic reduction of 2,4-dinitrochlorobenzene is rather problematic. 0.1 M NaOH is recommended as the supporting solution for analytical control of conversion of 2,4-dinitrochlorobenzene and a mixture of 2-chloro-5-nitroaniline and 4-chloro-3-nitroaniline in reaction solutions obtained by preparative electroreduction of 2,4-dinitrochlorobenzene. [ABSTRACT FROM AUTHOR]

Published data on the stability of Pu(VI) and Pu(V) in solutions of mineral and organic acids and their salts are analyzed. The hypothesis that Pu(VI) in acid solutions disappears owing to the disproportionation to Pu(VII) and Pu(V) cannot be accepted because of high redox potential of the Pu(VII)/(VI) couple. Plutonium( VI) is reduced owing to radiation-chemical reactions induced by its α-radiation and to the formation of a dimer (so-called excimer) by an excited Pu(VI) ion with an unexcited Pu(VI) ion, which rapidly decomposes to Pu(V) and HO. Plutonium(V) disappears owing to disproportionation and radiation-chemical processes. [ABSTRACT FROM AUTHOR]

Small controlled amounts of palladium were electrochemically deposited onto various carbon supports from solutions of glycinate-chloride complexes of palladium(II) in order to obtain palladium catalysts suitable for use in fuel cells. The catalytic activity of the resulting catalytic layers was studied in reactions of reduction of atmospheric oxygen and oxidation of methanol and ethanol in acid and alkaline media by measuring cyclic voltammetric curves on a rotating disk electrode. [ABSTRACT FROM AUTHOR]

Features of the behavior of uranyl ions in POC13-MCl x -235UO solutions (M = Ti, Si, Zr, Sn, Sb) were considered. Irreversible accumulation of U(IV) in the course of synthesis of POCl3-SnCl4-235UO solutions prepared from water-containing U(VI) compounds, excluding UO2(ClO4)2 · 5H2O, was found. The reaction rate increases with increasing uranyl concentration, k l[U(IV)] ∼ (1.6±0.2) × 10−6 s−1 ( T = 380 K). The U(IV) accumulation was also observed on heating ( T = 360–380 K) POCl3-SnCl4-235UO and POCl3-SbCl5-235UO solutions hermetically sealed in glass cells and on irradiating them by the light of a xenon lamp. In POCl3-SbCl5-235UO solutions prepared from UO2(C1O4)2 · 5H2O, U(IV) disappears within several days after stopping the irradiation. The reduction of U(VI) is caused by formation of uranyl dichlorophosphate complexes and by deactivation of uranyl excitation with chlorine-containing agents. [ABSTRACT FROM AUTHOR]

The electrochemical behavior of Cu30Ni alloy hydride in 1 N NaOH solution was studied. One-shot and cyclic voltammograms, chronocoulometric, amperometric, and potentiometric curves, as well as time variation of the open-circuit (free-corrosion) potential E cor, were measured. Both types of voltammograms show a limiting current plateau, which can be explained by a preceding chemical reaction of the hydride decomposition. It is concluded (from the character of E cor vs. t curves) that the hydride decomposition involves the alloy's copper component activation through the copper oxide reduction with hydrogen. The alloy hydride decomposition rate was determined by using chronocoulometry: V = 4.6 × 10–4 A/cm2. No potential arrest was observed in the E cor vs. t and E vs. t curves, which is due to concurrent reactions of electrochemical and chemical recombination involving hydrogen atoms adsorbed at the alloy surface. [ABSTRACT FROM AUTHOR]

Acetohydroxamic acid (AHA) is an important complexant/reductant for Pu(IV) in the UREX process. It decomposes in the presence of nitric acid. In literature, its decomposition kinetics in nitric acid is traditionally reported as pseudo-first order reaction. In this study, new experimental data were reported for kinetics experiments under wide consecration conditions. It was found that the decomposition reaction was first order with respect to both the components hence overall second order. [ABSTRACT FROM AUTHOR]

A nickel-containing shungite powder has been synthesized by means of chemical reduction from aqueous solutions. The chemical composition and radio-absorbing properties of this powder have been studied. [ABSTRACT FROM AUTHOR]