Experiments for 'Cu'
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 'Cu':
EXPERIMENT 1
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This is a very nice experiment, involving beautifully coloured compounds,
but it is a hazardous experiment as well, due to the use of mercury (II)
compounds.
Mercury (II) builds a complex with excess iodide, [HgI4]2-, which gives a
beautiful bright yellow precipitate with Ag+ and a beautiful bright brick-
red precipitate with Cu+.
EXPERIMENT 2
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Sulfide gives precipitates with some metals, which do not dissolve in
strong acids. These sulfides, however, can easily be dissolved, when an
oxidizing agent is used.
Sulfide is easily oxidized by moderately strong oxidizers.
EXPERIMENT 3
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This sequence of experiments shows that sulfite is capable of reducing
silver (I), copper (II) and iron (III), but that these reactions all
show their own peculiarities. Sulphur in the +4 oxidation state is a
mild reductant.
EXPERIMENT 4
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Copper (II) reacts with thiocyanate in a complex way.
EXPERIMENT 5
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Copper (II) reacts with thiocyanate in a complex way.
EXPERIMENT 6
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Copper (II) reacts with ferrocyanide and builds a fairly stable compound.
EXPERIMENT 7
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Vitamin C is a strong reductor in alkaline environments. Copper (II) is
reduced to copper (I).
EXPERIMENT 8
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Copper hydroxide is decomposed upon heating and loses water, even if
it is surrounded by water.
EXPERIMENT 9
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Copper is oxidized by a mix of concentrated hydrochloric acid and
hydrogen peroxide. When the peroxide is used up and there is still an
excess amount of hydrochloric acid, then the copper (II) appears to
oxidize the copper metal, under the formation of an intensely colored
complex. (What is the constitution of this complex??)
When the solution is diluted with water, then the intensely colored
complex is destroyed and a white crystalline precipitate of CuCl is
formed. If too much water is used, then no clear precipitate is formed.
EXPERIMENT 10
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Copper (II) reacts with metallic copper, in the presence of a large amount
of hydrochloric acid, forming an intensely colored compound. This compound
contains copper (I). If copper (II) is used alone, with hydrochloric acid
and peroxide, then the strong coloration does not occur.
EXPERIMENT 11
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Hydroquinone is capable of reducing copper (II) to copper (I) in alkaline
environments. The copper is not reduced to its metallic form.
EXPERIMENT 12
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Copper hydroxide is not capable of oxidizing methanol.
EXPERIMENT 13
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Formaldehyde is not capable of reducing Fehlings reagent within a few
minutes at temperatures of appr. 60 C.
EXPERIMENT 14
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Metol is capable of reducing copper (II) to copper (I) in alkaline
environments.
EXPERIMENT 15
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Copper (II) builds a complex with citrate ions. When treated with ferro
cyanide, this complex is destroyed, resulting in copper ferrocyanide.
When treated with ferricyanide, then it is not destroyed. Apparently
copper ferricyanide dissolves better in water, such that the complex
with citrate can remain in solution.
EXPERIMENT 16
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Copper (II) builds a coordination complex with glucose in alkaline
environments. On heating, the glucose is oxidized by the copper (II)
and orange/red Cu2O precipitates.
EXPERIMENT 17
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Copper (I) iodide dissolves in dilute ammonia, resulting in a colorless
liquid. Copper (I) builds a coordination complex with ammonia. This
complex is oxidized by oxygen from the air exceedingly easily.
EXPERIMENT 18
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Copper gives a coordination complex with catechol, but only in alkaline
environments. This complex is easily oxidized by oxygen from air. Iron
also forms a complex in acidic media, probably by a combined red/coordination
reaction.
EXPERIMENT 19
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Copper (II) gives a coordination complex with ascorbic acid in neutral or
slightly acidic environments. In alkaline environments copper (II) is
reduced rapidly by ascorbic acid / ascorbate.
EXPERIMENT 20
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Copper builds a complex with urea, which has a pale purple color (or is
this due to contamination of the urea with traces of biuret?). The copper,
bound to urea, does not build the intense blue cuprammine complex with
ammonia.
EXPERIMENT 21
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EDTA builds a coordination complex with copper (II). This complex has a
color, resembling the color of simple hydrated copper (II), but it is
much more intense and it has a slightly more cyan-like color.
This complex is not stable in strongly alkaline environments.
EXPERIMENT 22
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When copper (II) is reduced by dithionite in neutral environments, then
a dark red/brown precipitate is formed (metallic copper??). When reduced
in alkaline environments, then hydrous copper (I) oxide is formed.
EXPERIMENT 23
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When tetraammine-copper (II) is reduced by dithionite in excess ammonia,
then a colorless copper (I) complex is formed, which remains dissolved.
EXPERIMENT 24
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Copper builds higher oxides than CuO when strong oxidizing agents are
present in alkaline environments. Probably these are not copper (III)
compounds, but the oxo-ion probably is replaced by peroxo or superoxo.
EXPERIMENT 25
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Decomposition of hydrogen peroxide is catalyzed by cuprammine complex.
EXPERIMENT 26
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Copper tetrammine sulfate only dissolves very slowly in not too strongly
diluted sulphuric acid.
EXPERIMENT 27
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Copper (II) reacts with thiourea, forming a pale/yellow precipitate, looking
like sulphur. This precipitate, however, is not sulphur (what is it???).
EXPERIMENT 28
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In alkaline environments, copper (II) shows remarkable behavior, when brought
in contact with strong oxidizers or reductors.
EXPERIMENT 29
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Hydroxyl amine sulfate (containing protonated hydroxyl amine) is not capable
of reducing copper (II). When the liquid becomes basic (releasing free
hydroxyl amine), then the copper (II) is reduced to copper (I).
EXPERIMENT 30
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Copper builds a remarkable complex with ascorbic acid and is easily
reduced by ascorbic acid in alkaline environments. Copper (II) builds
a brown compound with hydrogen peroxide in alkaline environments.
EXPERIMENT 31
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Copper (II) ions form a brown complex with bromide ions, but only when the
product of concentration of copper and bromide is high.
In strongly acidic environments, bromide gives a red/brown/purple complex
with cupric ions.
EXPERIMENT 32
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Copper and nickel carbonates (basic), which do not dissolve in water, do
dissolve in ammonia, due to formation of a complex with ammonia.
Cobalt carbonate also dissolves, but now an additional reaction occurs,
taking up oxygen from the air.
EXPERIMENT 33
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Copper (II) is reduced by sulfite. With chloride the resulting copper (I)
can be kept in solution. The copper (I) compound is very susceptible
to oxidation by oxygen from the air.
EXPERIMENT 34
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Nitrous acid (or its decomposition product) forms a dark brown coordination
complex with ferric ions. With copper (II) also a coordination complex is
formed. In relatively strongly acidic environments, these coordination
complexes are destroyed/not formed.
EXPERIMENT 35
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Copper (II) does not form a coordination complex, nor does it form a
precipitate with bromate. It does not react.
EXPERIMENT 36
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When copper dissolves in aqua regia, then a colorless gas is produced.
Oxidation apparently proceeds in a different way, when compared with
dissolving copper in nitric acid.
EXPERIMENT 37
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Copper (II) builds a coordination complex with acetate ions. On addition
of hydrogen peroxide, this complex is destroyed and a new compound is
formed.
EXPERIMENT 38
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Copper (II) does not form a coordination complex with phosphates and/or
phosphoric acid.
EXPERIMENT 39
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Copper (II) is reduced by hydroxyl amine very quickly in alkaline
environments. Yellow copper (I) hydroxide/oxide is formed.
EXPERIMENT 40
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Copper (II) amine complex is reduced to a colorless copper (I) amine
complex by hydroxyl amine. The copper (I) complex is oxidized by oxygen
from the air very easily.
EXPERIMENT 41
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Copper (II) salts give a cyan precipitate with bicarbonates. The color of
this precipitate is the same as the color of commercially available basic
copper carbonate.
This precipitate reacts with hydrogen peroxide, forming a dark green/brown
compound. With sulfite it also reacts, forming a brownish compound, which
on acidification dissolves, forming a light yellow/brown clear liquid.
EXPERIMENT 42
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Copper (II) is reduced by metabisulfite / sulphur dioxide to a copper (I)
compound, but some heating is required in order to make this reaction
fast.
EXPERIMENT 43
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When copper (II) is present in hydrochloric acid, then it does not react
immediately with hydroxyl ammonium, some heating is required to have a
reaction, resulting in formation of a dark green/brown compound. When the
liquid is made alkaline with excess ammonia, then it quickly becomes
colorless, due to reduction of copper (II) to copper (I), which forms a
colorless complex with ammonia.
A very peculiar reaction occurs on oxidation by oxygen from air. The liquid
is covered by a very thin shiny layer, looking like a strongly coloured oil
on water. It is not clear what it is, more research is needed.
EXPERIMENT 44
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Copper (II) chloride reacts violently with metallic aluminium. When copper
sulfate or nitrate is used, then this reaction does not occur. When sodium
chloride is used, this reaction also does not occur. Both cupric ions and
chloride ions are needed for quick reaction with aluminium, but if they are
present, then a very violent reaction occurs.
EXPERIMENT 45
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Cupric chloride forms a coordination complex when a large excess of chloride
is present and this chloro cuprate complex easily oxidizes metallic copper.
This oxidation causes formation of copper (I), which forms a very dark
brown complex in the presence of copper (II) and hydrochloric acid (what
is this dark brown compound?).
EXPERIMENT 46
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Cupric chloride dihydrate is dehydrated by concentrated sulphuric acid.
EXPERIMENT 47
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Cupric chloride dihydrate dissolves in acetone. The solution becomes yellow
at low concentrations, green/brown at higher concentrations. When sulphuric
acid is added, then a precipitate of anhydrous cupric chloride is formed.
EXPERIMENT 48
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Copper (II) chloride dissolves in fairly concentrated nitric acid, but it does
not dissolve easily. Only a small amount can be dissolved. It dissolves with
a bright green/cyan color. Aluminum metal is not attacked by this solution.
Slight dilution does not make the liquid more active towards aluminum. When a
lot of sodium chloride is added, then the aluminum is attacked and it
dissolves.
EXPERIMENT 49
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Nitrite forms a dark green coordination complex with copper (II) ions in
neutral environments. When acidified, then a new coordination complex
(dark blue with a grey hue) is formed in the presence of chloride of
very high concentration. This is not formed when chloride is absent.
EXPERIMENT 50
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Copper (II) ions are complexed by EDTA Na4, but when the liquid is acidified,
then the copper ions are not coordinated anymore.
EXPERIMENT 51
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Copper (II) carbonate gives a very dark compound with H2O2, is this a
peroxide compound or just copper oxide?
EXPERIMENT 52
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Copper (II) forms a very dark coordination compound with concentrated
bromide in highly acidic environments. When metallic copper is added,
then this complex quickly disappears and the liquid almost becomes
colorless.
EXPERIMENT 53
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Copper sulfate dissolves in methanol quite well. A blue solution is obtained.
Copper chloride dihydrate also dissolves in methanol quite well. A green
solution is obtained.
With thiocyanate a deep brown complex is formed, which dissolves in
methanol, but at higher concentration this precipitates.
With cyanide, a dirty green compound is formed, which, however, quickly
turns white. This probably is copper (I) cyanide.
EXPERIMENT 54
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Copper (II) forms a yellow/brown coordination complex with cyanide in
acidic media in the presence of chloride.
EXPERIMENT 55
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Copper (II) chloride is reduced by hydroxyl amine, when dissolved in
ethanol. First, the solution becomes much darker and apparently, a mixed
oxidation state complex of copper (I) and copper (II) is formed. Finally,
all copper (II) is reduced to copper (I).
This experiment is another example, which shows that copper (I) and copper
(II), when in solution at the same time, form a highly colored complex.
EXPERIMENT 56
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Copper (II) chloride dihydrate dissolves in ethyl acetate, albeit only
in small amounts. With thiocyanate, a dark coordination complex is formed,
also in ethyl acetate.
EXPERIMENT 57
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Copper (II) forms a coordination compound with ethyl acetate, which has
reacted with hydroxyl amine.
EXPERIMENT 58
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Borohydride is capable of reducing copper to its metallic state.
EXPERIMENT 59
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Copper hydroxide easily looses water, when it is heated, even if it is
completely covered with water.
EXPERIMENT 60
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Copper (II) ions form a complex with DMSO and chloride at the same time. This
is a green complex (somewhat limegreen, however, a little bit more towards pure
green). This complex is soluble in water and probably also is decomposed by
replacement of ligands by water molecules.
EXPERIMENT 61
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Copper (II) chloride and nitrite gives a deep green complex in water. This
combination gives a dark brown complex in DMSO.
EXPERIMENT 62
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Copper (I) oxide, when added to sulphuric acid, disproportionates. Metallic
copper is formed and a blue solution of copper (II) sulfate. The copper (I)
oxide looses its oxide ion to the acid and that would leave aqueous copper (I)
ions. These are not stable and disproportionate at once.
Copper (I) oxide, added to hydrochloric acid dissolves and forms a solution,
containing a copper (I) complex, [CuCl2]-. This complex is very easily oxidized
by oxygen from the air and then a dark brown mixed valency complex of copper
(I) and copper (II) is formed.
EXPERIMENT 63
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Copper(I) iodide dissolves in a concentrated solution of potassium iodide.
In such a solution the complex ion CuI2(-) is formed. On dilution, this ion
decomposes and a precipitate of CuI is formed again.
Copper(I) iodide does not dissolve in hydrochloric acid, or just a small
amount dissolves.
EXPERIMENT 64
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Copper(I) iodide darkens on heating, but at the same time it decomposes, giving
deep purple iodine vapor.
EXPERIMENT 65
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Tannine (a polyphenolic compound of large molecular weight of indeterminate
composition) reacts with many metal ions, forming highly coloured complexes.
It also shows some other reactions. The exact type of reactions is not
always clear.
The tannine, used in these experiments, was brown. It's intended use is
as an additive for making wine.
EXPERIMENT 66
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Chromium (III) chloride hexahydrate cannot be dehydrated by simple heating.
Copper (II) chloride dihydrate can perfectly be made anhydrous.
EXPERIMENT 67
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Analysis of the composition of the dutch coin 'dubbeltje' shows that it
does not contain any copper or just a very small quantity of it.
EXPERIMENT 68
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It appears that copper (II) ions catalyse the oxidation of pyrogallol by
hydrogen peroxide.
EXPERIMENT 69
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Copper (II) apparently catalyses the oxidation of pyrogallol by oxygen from
the air.
EXPERIMENT 70
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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 71
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Acetyl chloride is capable of dehydrating copper(II) chloride, and it even is
capable of replacing sulfate ion by chloride, itself being converted to acetyl
sulfate.
EXPERIMENT 72
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When a solution of copper sulfate is added to a solution of hydroxyl ammonium
chloride in dilute solution of NaOH, then a dirty green precipitate is formed.
At some places the precipitate becomes yellow. When the liquid is shaken, then
all of the precipitate dissolves and a colorless liquid is obtained. On
standing, a thin layer of solid material is formed on the surface of the
liquid. This layer has a dirty green color.
Hydroxyl amine reduces copper(II) at high pH and a colorless complex of
copper(I) is formed, which at really high pH becomes unstable with formation of
hydrous copper(I) oxide.
EXPERIMENT 73
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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 74
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When copper ions are brought in contact with periodate, then a yellow/green
precipitate is formed. This precipitate very easily dissolves in hydrochloric
acid, giving chlorine gas and other products.
When the same is done with manganese(II) ions instead of copper ions, then a
brick-red precipitate is formed, which does not easily dissolve in hydrochloric
acid.
EXPERIMENT 75
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Hydrazine seems to be able to reduce copper(II) to copper(I) in mildly acidic
environments. In alkaline environments the reaction is fast and most likely
elemental copper is produced in the reaction.
EXPERIMENT 76
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Copper(II) ions form a pale green complex with a yellowish hue. When the
solution is heated to boiling, then the copper(II) is reduced to metallic
copper.
EXPERIMENT 77
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Anhydrous copper (II) chloride, when added to acetone, dissolves with a
yellow/brown/green color. When a saturated solution is allowed to stand for
several hours at 10 C or so, then red/brown crystals are formed. When the
crystals are heated, then they become dark brown and a flammable vapor is
produced (most likely acetone).
Probably, from a saturated solution of copper(II)chloride in acetone, an adduct
is formed of the form CuCl2.nCH3COCH3.
EXPERIMENT 78
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When ethylene diamine is added to anhydrous copper sulfate, then no complex is
formed. When a little water is added, then suddenly a deep blue/purple complex
is formed. Apparently, some water is needed for formation of the ethylene
diamine complex.
EXPERIMENT 79
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Copper(II) ions are capable of forming a mixed azide/ammonia complex which has
energetic properties.
EXPERIMENT 80
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Diethylamine does not as easily form typical ammine-like complexes, like
ammonia.
EXPERIMENT 81
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Reduction of tetrachlorocuprate with ascorbic acid
EXPERIMENT 82
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Thionyl chloride and copper nitrate react with each other, giving gaseous
products and solid anhydrous copper(II) chloride remains behind.
EXPERIMENT 83
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Copper(II) can be reduced to the very peculiar compound CuH by hypophosphorous
acid, but only under very specific conditions. The compound CuH is quite
unstable and easily looses hydrogen.
In the presence of chloride ions, no CuH is formed, but CuCl is formed instead.
EXPERIMENT 84
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Anhydrous copper (II) chloride, when added to acetone, dissolves with a
yellow/brown color. If more copper (II) chloride is added, than can be
dissolved in acetone, then the remaining solid becomes red/brown, like iron
rust.
When the red/brown solid is added to water, then at once it becomes green and
then it dissolves, just as normal copper (II) chloride. The dilute solution
becomes light blue.
EXPERIMENT 85
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Copper(II) ion and sulfite ion react in aqueous solution. A dirty green/yellow
precipitate is formed when solutions with these ions are mixed. When there is
excess sulfite, then on slight heating the precipitate redissolves and the
liquid becomes colorless.
Apparently a coordination complex is formed with copper(I). This coordination
complex is very air-sensitive. It reacts with air, giving a dirty
brown/green/yellow precipitate.
EXPERIMENT 86
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Cesium forms a solid red/brown chloro complex of copper(II). This complex is
very remarkable, due to its rust-like color, which is very uncommon for
copper(II) salts.
EXPERIMENT 87
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Copper(II) ions and azide ion give rise to formation of an intensely dark
colored precipitate/complex.
EXPERIMENT 88
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Finely divided magnesium powder violently reacts with wet cupric nitrate and
with wet ferric nitrate. The dry solids do not react.
EXPERIMENT 89
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Copper(II) oxide slowly dissolves in a highly concentrated solution of citric
acid and after a while a brightly colored crystalline solid is formed, which
most likely is copper(II)citrate.
EXPERIMENT 90
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Copper(II) ions form no complex with tetrathionate ion and there also is no
formation of a precipitate. Even boiling does not cause a visible change.
EXPERIMENT 91
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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 92
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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 'Cu'