No abstract available

No abstract available

[en] The electrochemical behaviour of vanadium (5) in 0.1-9 M HCl has been examined by voltammetry with a platinum rotating disc electrode. The kinetic nature of the limiting current of vanadium (5) reduction in 0.1-4.2 M HCl and the diffusion nature in moreconcentrated HCl have been established. A catalytic effect of platinum oxide films on vanadium (5) electroreduction has been observed. Vanadium (5) was determined in the presence of 40 times its amounts of vanadium (4) in 6.0-6.2 M HCl. It is recommented to determine vanadium(5) in the presence of tungsten (4) and other components in solutions modelling vanadium catalysts of sulfuric acid production

No abstract available

[en] Certain problems of mechanism and kinetics of electrode processes of Mo(6) reduction in HCl solutions are studied. It is shown that on Pt-electrode the process of electrotransformation of Mo(6) is mainly controlled by linear diffusion which is complicated with adsorptional phenomena. Using coulonopolarographic method it is established that the number of electrons, participating in the process is eqial to one

[en] The Mo(6) electroreduction depending on different factors with the the purpose of establishing optimum conditions for determining Mo(6) in the presence of ions of accompanying elements (V, Re, W) It has been found that optimum parameters of oscillopolarograms (OP) survey in case of Mo(6) reduction are: background - 0.01 M HCl, inital scanning potential 0.5V voltag, supply velocity 1V/cs. The presence even of 100-fold of V(5), Re(7), W(6) excess does not exert any influence on the peak form and reduction potential of Mo(6). The technique of oscillopolarographic Mo(6) determination in solutions of its salts, ores and concentrates with 10^-6-10^-4 M sensitivity with sufficient selectivity and reducibility

[en] Electrochemical Tl(1), In(3) and Ga(3) behaviour in mercury-graphite electrodes by the method of direct-current and alternating-current voltammetry is studied. Comparison of mathematical models and their experimental check are carried out. Possibility to forecast the investigation results is shown, and the procedure for mercury-graphite electrode surface formation necessary in measurements is chosen

[en] Voltammetric behaviour of vanadium (5) and (4) has been studied in H₂SO₄, H₃PO₄, HCl solutions on a rotating graphite disc electrode. The advantage of the electrode over similar platinum electrode has been shown. Optimal conditions have been chosen for determining vanadium (5) and (4) in phosphoric acid solutions. The procedure developed was tested on catalysts of sulphuric acid production. The procedure is characteristic of better precison compared with the arbitration procedure

No abstract available

[en] Using X-ray analysis, X-ray photoelectron spectroscopy, gravimetry, thermogravimetry and potentiometric titration methods studied has been composition of molybdenum oxide films, formed upon platinum cathode in the course of electrolysis of Mo(6) acetate-buffer solution. It is shown that in the first approximation the film composition corresponds to the 6Mo₂O₅x2MoO₂xH₂O formula