Questão de Química

To prepare the Cr (VI) oxoanion, chromite ore, FeCr O , which 2 4 contains Fe (II) and Cr (III), is dissolved in molten potassium hydroxide and oxidized with atmospheric oxygen. In this process, the iron and chromium, respectively, are converted to FeO 2− and CrO 2−, so chromium reaches its maximum 4 4 oxidation state (equal to the group number) but iron does not. Dissolution in water followed by filtration leads to a solution of the two oxoanions. The ions can be separated by taking advantage of the greater oxidizing power of Fe (VI) relative to that of Cr (VI) in acidic solution. Acidification leads to the 2− 2− reduction of FeO and the conversion of CrO to dichromate 4 4 Cr O 2−; the latter conversion is a simple acid-base reaction, 2 7 and not redox reaction. SHRIVER, D.F.; ATKINS, P. Inorganic Chemistry. Oxford: Oxford University Press, 1996. A partir da interpretação do texto, conclui-se que