Experiments for 'cobalt sulfate'
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 'cobalt sulfate':
EXPERIMENT 1
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Aluminum reacts vigorously with water, when its passivating layer of oxide
is effectively destroyed. This can be achieved by using tetrachloro or
tetrabromo complexes of copper (II).
Acid can also be used to destroy the passivating layer, but this takes
considerably more time.
Cobalt has a similar effect as copper (II), but it is less pronounced.
EXPERIMENT 2
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Cobalt (II) gives a precipitate with bicarbonate, which probably is
cobalt carbonate. This precipitate is formed, while driving off CO2.
EXPERIMENT 3
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Cobalt (II) gives a blue precipitate with hydroxide, but this precipitate
quickly turns pink / purple / light brown after its formation.
EXPERIMENT 4
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Cobalt (II) gives a deep blue precipitate with silicates.
EXPERIMENT 5
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Cobalt (II) gives a precipitate with bicarbonate, which reacts with hydrogen
peroxide, probably forming a cobalt (III) compound.
EXPERIMENT 6
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Cobalt (II) salts give a blue/green precipitate when dilute ammonia is added.
This precpitate is fairly stable towards air. When more concentrated ammonia
is used, then a dark brown compound is formed, but this compound is formed
by contact with air. On addition of hydrogen peroxide also a very dark
brown compound is formed.
When the pH is increased strongly, then the blue precipitate is not stable
anymore, instead a dark bright blue compound is formed, which, however,
quickly turns pink.
When a large amount of ammonia is replaced by ammonium, then the blue
precipitate is not formed anymore, but a coordination complex is formed,
which is very easily oxidized by oxygen from the air.
EXPERIMENT 7
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Cobalt sulfide does not dissolve in dilute acids and it does not dissolve
in concentrated hydrochloric acid (at least not easily). With the help of
hydrogen peroxide it is possible, however, to dissolve the compound.
EXPERIMENT 8
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Cobalt (II) gives a green precipitate with ferrocyanide and a dark red/
purple precipitate with ferricyanide. The green precipitate cannot be
converted to the red one by means of oxidation by hydrogen peroxide, but
another, dark blue, compound is formed.
EXPERIMENT 9
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Cobalt sulfate dissolves in methanol, albeit not as well as in water. The
liquid obtained is colored quite intensely. The dilute solution of cobalt
sulfate in methanol looks more pink/purple than even the most concentrated
aqueous solution.
With thiocyanate a deep blue complex is formed in methanol.
EXPERIMENT 10
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Borohydride is capable of reducing cobalt (II) to the metallic state.
EXPERIMENT 11
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In this experiment, some of Werner's experiments are repeated. Here it is
shown that cobalt forms beautifully colored carbonato complexes. The exact
complex formed, depends on the experimental conditions. It is remarkable
what kinds of reactions are shown by cobalt in its complexes and it is
really difficult to precisely determine what is happening and it even is
difficult already to get the same results without precisely specifying the
exact experimental conditions (e.g. using HCl instead of H2SO4 already
results in a different outcome).
EXPERIMENT 12
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When hydrated sulfate-salts are heated, which only loose water, then their
properties strongly change. The color changes, but also the solubility
properties change a lot. The sulfate salts loose water easily, but no acid
(H2SO4 or SO3).
EXPERIMENT 13
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A solution of cobaltous acetate is hydrolysed when the solution is heated. When
the liquid cools down again, then the effect is reversed again. The visual
result is formation of a precipitate on heating and the slow redissolving of
the precipitate on cooling down.
EXPERIMENT 14
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Copper(II) ion and iron(III) ion form complexes with acetyl acetate (acac) in
aqueous solution. Cobalt does not form a complex, at least not visibly.
EXPERIMENT 15
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Cyanate ion forms complexes with many metal ions. These complexes have a strong
color and are not stable in acidic solution.
End of results for 'cobalt sulfate'