Experiments for 'zinc'
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 'zinc':
EXPERIMENT 1
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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
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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
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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
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Niobium pentachloride dissolves in DMSO, and slowly reacts with it, giving a
really foul smelling compound.
EXPERIMENT 5
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Vanadium pentoxide can be easily dissolved in acid, when a reductor is
present. Then it is dissolved and at the same time reduced to vanadyl
(vanadium (V) to vanadium (IV)). With very strong reducing compounds,
further reduction to vanadium (III) or even vanadium (II) is possible.
EXPERIMENT 6
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Vanadium(III) hydroxide apparently forms a precipitate and does not
dissolve in strongly alkaline liquids.
Vanadium (III) and (IV) are oxidized by peroxodisulfate to vanadium (V).
EXPERIMENT 7
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Vanadium (III) apparently builds a coordination complex with EDTA in
strongly acidic environments. This complex is brown.
EXPERIMENT 8
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Cr(III) can be reduced to Cr(II) by a zinc nail. On reoxidation to Cr(III)
a coordination complex appears to be created, both with sulfate and with
chloride.
EXPERIMENT 9
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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.
EXPERIMENT 10
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Niobium pentachloride reacts violently with water, releasing hydrogen chloride.
Niobium pentachloride also reacts vigorously with hydrochloric acid. The liquid
first remains clear, but on standing it becomes turbid.
When zinc is added, then a deep blue compound is formed, which on dilution
becomes brown, and finally becomes colorless and turbid.
End of results for 'zinc'