POLAROGRAPHIC INVESTIGATION OF THE REDUCING ABILITY OF NONSTOICHIOMETRIC TUNGSTEN(VI) OXIDE

Polarographic analysis was carried out in order to determine the devia tion of WO3 from stoichiometry during interaction of WO3 preparations with Fe3+ ions. Samples of WOx, heated in an inert atmosphere, were di ssolved in a sodium citrate solution in the presence of Fe-3 divided b y ions and in a mixture of boric, sulfuric, and phosphoric acids to st abilize Fe2+ ions formed in the process. The stoichiometric index x in WOx was calculated from the results of determination of the weight of Fe(II) and checked by the method of varying sample weights. The syste matic error accorfing to the t-criterion with the confidence level 0.9 5 was insignificant. The random error was characterized by the relativ e standard deviation s(r) = 0.0001 - 0.0002 for x = 2.9984 - 2.9991.