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Experiments for 'Re'
Below follows a summary of all experiments, matching your
search. Click one of the EXPERIMENT hyperlinks for a complete description of the
experiment.
Results for 'Re':
EXPERIMENT 1 --------------- Rhenium is oxidized easily by nitric acid. The oxidation product is a color- less compound, soluble in water (according to literature it is perrhenic acid, HReO4). Perrhenic acid is not a really strong oxidizer. It can be reduced by zinc, but addition of sodium sulfite does not result in formation of the same compound. Hydrogen peroxide is capable of oxidizing back to perrhenic acid, but some light yellow compound remains. What is it?
EXPERIMENT 2 --------------- Rhenium, when dissolved in nitric acid, gives colorless perrhenate ions, [ReO4]-. With zinc, in the presence of hydrochloric acid of sufficient concentration, this can be reduced to a yellow/green species. With cyanide, in alkaline environment this forms a brown and clear solution. The yellow/ green species may be [ReCl6]2-, which according to literature is green. With cyanide, a complex may be formed.
EXPERIMENT 3 --------------- Rhenium can be oxidized to colorless perrhenate [ReO4]-, with nitric acid. With zinc it can be reduced to a yellow/green species in the presence of hydrochloric acid at sufficient concentration. This species apparently is not reduced any further with borohydride in alkaline environments. In acidic environments, a dark brown/black compound can be formed easily, due to reduction of thiosulfate to sulfide by the borohydride. The sulfide forms a dark compound with rhenium. With sulfite, perrhenate nor the yellow/green compound can be reduced to a lower oxidation state.
EXPERIMENT 4 --------------- Rhenium forms complexes with thiocyanate in more than one oxidation state. Here a rhenium (IV) thiocyanate complex is made and then oxidized to rhenium (V). Historically these complexes have been used to detect minute traces of rhenium due to the intense colours formed.
End of results for 'Re'
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