Experiments for 'nitric acid'
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 'nitric acid':
EXPERIMENT 1
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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 2
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The hexanitrito cobaltate (III) ion is affected by concentrated nitric
acid. It changes from yellow to brown. What is the nature of this change?
EXPERIMENT 3
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Mercury (II) ions produce a bright orange colored precipitate with iodide.
EXPERIMENT 4
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Mercury (II) salts give an oxide/hydroxide, which does not dissolve in
large excess amounts of alkaline solutions. Ammonia does not dissolve
the precipitate of mercury (II) oxide/hydroxide.
EXPERIMENT 5
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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 6
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Aluminium (III) does not form colored compounds with ferrocyanide nor with
ferricyanide. Manganese (II) reacts with both of them, but a colored
compound is formed with ferricyanide only.
EXPERIMENT 7
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Potassium ferrocyanide reacts with concentrated nitric acid. The compound
which is formed is dark brown/green. What is this compound?
Is the dark brown/green color due to formation of a Fe(NO)+ complex, well
known from the brown-ring test for nitrates?
EXPERIMENT 8
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Ferric oxide (Fe2O3, dark red/brown) dissolves in hydrochloric acid and
nitric acid, but with extreme difficulty and in very small quantities.
EXPERIMENT 9
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Persulfate is capable of oxidizing Mn2+ in acid environments, but silver (I)
is needed as a catalyst. Oxidation, however, is not easy and just a small
part is oxidized to permanganate, a large part is oxidized no further than
MnO2.
EXPERIMENT 10
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Permanganate is a strong (and dangerous) oxidizer, when combined with
concentrated sulphuric acid. It is capable of lighting paper and acetone,
without the use of matches.
Permanganate, mixed with a mixture of nitric acid and sulphuric acid is
a strong oxidizer as well, but not as powerful as when mixed with
sulphuric acid only.
EXPERIMENT 11
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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 12
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Thymol is oxidized by concentrated nitric acid, resulting in the formation
of a dark green compound, which however by further oxidation is destroyed
again and a water-soluble compound remains.
EXPERIMENT 13
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Benzoate and citrate, used together, give rise to formation of a strange
phenomenon, when heated with concentrated nitric acid. It looks as if one
large crystalline mass is created. It must be investigated, whether the
iron is essential for this or not.
EXPERIMENT 14
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Acrylic acid fairly easily is oxidized in dilute aqueous solution, while propanoic acid is not.
The double bond between two C-atoms makes the molecule more reactive.
EXPERIMENT 15
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Lead hydroxide is oxidized by hydrogen peroxide. The resulting compound
does not dissolve in dilute nitric acid.
EXPERIMENT 16
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When aqueous ammoniacal silver is reduced by glucose, a nice silver mirror
is produced.
Peroxosulfate is capable of oxidizing silver to a higher oxidation state
(+2 or +3), even in acidic environments.
EXPERIMENT 17
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Silver (I) is not reduced by hydroxyl amine in neutral environments. When
made alkaline, it is reduced to metallic silver immediately.
EXPERIMENT 18
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Silver (I) reacts with persulfate. Probably a higher oxidation state of
silver is produced (oxidation state II or III).
EXPERIMENT 19
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Silver (I) gives a precipitate with bromate. The compound silver bromate
does not dissolve well in water. When acidified, the compound still does
not dissolve, hence the acid HBrO3 is fairly strongly ionized, otherwise
the silver bromate would dissolve appreciably. The precipitate of silver
bromate, however, still shows strong oxidizing properties, meaning that
it is sufficiently soluble for releasing bromate ions in solution, needed
for the redox reaction to occur.
EXPERIMENT 20
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Silver (I) gives a precipitate with bicarbonate, which becomes yellow and
more compact on standing. With H2O2 a dark compound is formed, which
dissolves in nitric acid under formation of a gas. Is this dark compound
a higher oxide of silver (e.g. Ag2O2?).
EXPERIMENT 21
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Silver (I) ions, when treated with hydroxide give brown silver (I) oxide.
When hydrogen peroxide is added, then that is decomposed and the precipitate
of oxide does not change noticeably. When, however, hydrogen peroxide is
first mixed with a solution of a silver (I) salt and then the hydroxide is
added, then a black precipitate is formed. Probably this is finely divided
metallic silver.
EXPERIMENT 22
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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 23
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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 24
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Borohydride is capable of reducing copper to its metallic state.
EXPERIMENT 25
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Alkanes do not react strongly with NO2. Some NO2 dissolves in them.
EXPERIMENT 26
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A large set of compounds is checked on interaction with concentrated
nitric acid. Many reductors react violently with nitric acid.
EXPERIMENT 27
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When concentrated sulphuric acid is added to concentrated nitric acid,
then some heating can be observed.
The mixed acid reacts with tissue, but not as strongly as pure sulphuric
acid does. The mixed acid reacts with copper, but this reaction is not
as strong as the reaction with nitric acid only.
With citric acid and acetone no strong reaction occurs.
EXPERIMENT 28
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Nitric acid, mixed with sulphuric acid is a strong oxidizer. It is capable
of oxidizing iodine to iodate.
EXPERIMENT 29
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Cadmium selenide reacts vigorously with nitric acid, producing nitrous
fumes and a yellow/orange solid, which is filled with many small gas bubbles
and hence remains floating on the liquid.
Cadmium sulfide gives a similar reaction, but now a pale yellow solid is
formed. This yellow solid is sulphur.
EXPERIMENT 30
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Tellurium slowly dissolves in nitric acid.
EXPERIMENT 31
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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 32
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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 33
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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 34
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This is a set of experiments, demonstrating an interesting aspect of thallium
chemistry, in combination with different iodine-containing compounds.
EXPERIMENT 35
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When molybdate (VI) is reduced by a small amount of reductor, then a blue
compound is formed. When a larger amount of reductor is available, then a
black compound is formed.
EXPERIMENT 36
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Silver (I) gives a bordeaux-red precipitate with dichromate, which
slightly dissolves in water.
EXPERIMENT 37
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Chromium (III) is oxidized to dichromate (chrome (VI)) by persulfate. This
reaction is catalyzed by silver (I).
EXPERIMENT 38
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Chromium (III) apparently builds a coordination complex with hydroxyl amine,
but this complex does not simply form from chromium (III) salts and
hydroxyl amine. If chromium (III) is formed by means of reduction of
chromium (VI) in the presence of hydroxyl amine, then the complex is
formed. If hydroxyl amine is added to chromium (III) without redox reaction,
then another complex is created.
EXPERIMENT 39
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Chromium (III) builds a purple complex with EDTA, both when it is created
from dichromate and when it already exists and is brought in contact with
EDTA. When the pH is too low (or is this due to formation of a complex with
sulfate?), the formation of the complex does not occur.
EXPERIMENT 40
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Chromium (III) gives coordination complexes of all kinds of colours, when
formed from a redox reaction, starting with dichromate.
EXPERIMENT 41
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When dichromate is reduced by means of adding hydrogen peroxide, then after
the initial transient a green compound is formed, even when the acid in
which the dichromate is dissolved is nitric acid (nitrate is supposed to
not form a coordination complex with chromium (III)). Is this green compound
a coordination complex with nitrate? or with hydrogen peroxide?
This coordination complex can easily be destroyed by heating.
EXPERIMENT 42
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Dichromates are not capable of oxidizing nitrite in neutral environments.
When some acid is added, then the oxidation proceeds, but a fairly low
pH is needed for a fast and complete reaction.
EXPERIMENT 43
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Dichromate is capable of oxidizing tartaric acid and a colorless gas is
formed in this reaction (probably CO2). The liquid becomes purple/grey
(hard to describe color, depending on viewing illuminant).
The reaction product does not form a special complex in alkaline environment,
the familiar green color of chromium (III) in alkaline environments is
created. Addition of glycerol does not result in formation of a special
coordination complex.
When, however, dichromate is reduced by an excess amount of glycerol, then
a special coordinate complex appears to be formed, when the solution is
made alkaline. Even addition of acid does not destroy this complex.
EXPERIMENT 44
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Chromium (III) builds a nice brightly colored green complex with phosphates.
This compound has no bluish hue, like sulfate gives with chromium (III).
Chloride also builds a complex. Formation of these complexes is not on
simple addition of a chromium (III) salt to the corresponding anions.
Heating is required.
EXPERIMENT 45
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Dichromate reacts with hydrogen peroxide, yielding chromium (III) as the
final product, in acidic environments. In alkaline environments, chromium
(III) yields chromate with hydrogen peroxide.
EXPERIMENT 46
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Bromide is oxidized by hydrogen peroxide in acidic environments. Addition
of nitric acid strongly enhances the reaction.
EXPERIMENT 47
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Sodium bromide is not oxidized by concentrated nitric acid. However, when
a minute quantity of nitrite is added, suddenly the reaction starts and
quickly all bromide is oxidized.
EXPERIMENT 48
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Bismuth shows remarkable coordination chemistry with iodide and chloride.
In the absence of chloride, a black precipitate of BiI3 is formed. In the
presence of chloride, a deep yellow/orange compound is formed, but only
if also iodide is present. So this compound must be a complex of bismuth,
iodide and chloride.
EXPERIMENT 49
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Bismuth (III) forms a deep-orange iodo-complex and a yellow iodo-chloro
complex.
EXPERIMENT 50
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Bismuth forms a yellow complex with thiosulfate. In the presence of
thiosulfate, it still forms a deep orange complex with iodide, just as without
thiosulfate.
EXPERIMENT 51
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Tetra chloro auric acid (a.k.a. "gold chloride"), a gold (III) compound is
easily reduced to metallic gold, which forms a colloidal solution. With
strong reductors, the gold particles formed are so large that they form
a dark precipitate.
EXPERIMENT 52
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Oxidation of nickel by nitric acid.
EXPERIMENT 53
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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 54
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This experiment describes a qualitative method, useful for showing the
presence of minute quantities of manganese (II), which cannot be detected
by oxidation with H2O2 in alkaline environments anymore. Chloride ions
may not be present besides the manganese to be detected.
EXPERIMENT 55
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Nickel forms colored coordination complexes with EDTA.
EXPERIMENT 56
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Borohydride is capable of reducing nickel to the metallic state in
aqueous media.
EXPERIMENT 57
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Elementary antimony dissolves in aqua regia at a fairly high rate. While
it dissolves a lot of gas is produced. When the liquid is diluted with
water, then a white precipitate is formed, due to hydrolysis of the
reaction product. It looks as if the antimony is oxidized to the +3 oxidation
state.
EXPERIMENT 58
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Tin metal does not dissolve quickly in concentrated hydrochloric acid.
Tin metal only slowly dissolves in aqua regia.
The solution obtained is clear.
EXPERIMENT 59
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Nitrous vapors react with thiocyanate, building a red/brown compound, which
disappears again, when left in contact with air.
EXPERIMENT 60
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Nitric acid and formalin react vigorously, but some help is needed in
order to start the reaction.
EXPERIMENT 61
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When nitric acid is mixed with hydrochloric acid, then so called aqua regia
is obtained. This is a colorless liquid, which, however, is not very stable
and which decomposes. What are the decomposition products?
EXPERIMENT 62
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Methanol and nitrate/nitric acid do not react readily, not even at fairly
high temperature (appr. 90C).
EXPERIMENT 63
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Chromium metal does not dissolve al all in concentrated nitric acid, not even
when the acid is heated. It does dissolve in concentrated hydrochloric acid and
also in moderately concentrated perchloric acid, but in the latter some heating
is required.
EXPERIMENT 64
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Antimony trioxide does not dissolve in concentrated nitric acid, not even when
the liquid is heated to boiling. When some hydrochloric acid is added as well,
then it quickly dissolves, producing a colorless gas as well. It is oxidized to
the +5 oxidation state.
When this solution is diluted, then a white precipitate is formed. This white
precipitate must be hydrous Sb2O5. When a dilute solution of sodium sulfide is
added to this still strongly acidic solution, then H2S bubbles out of solution,
but also a lot of precipitate is formed, which has a beautiful bright
orange/red color.
EXPERIMENT 65
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Bismuth(III) in nitric acid solutoin is not oxidized by peroxodisulfate to a
bismuth(V) species.
EXPERIMENT 66
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Vanadium(V) in acidic solution is reduced by hypophosphite to vanadium(IV), but
there is no further reduction to a lower oxidation state.
EXPERIMENT 67
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Sodium sulfite reacts vigorously with 68% nitric acid.
EXPERIMENT 68
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Thallium(I) metaperiodate is very much like potassium metaperiodate, but it
decomposes easily due to an internal redox reaction in which thallium(III) is
formed, which forms a precipitate with periodate ion.
EXPERIMENT 69
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Nitric acid does not show a violent reaction with hydrazine, but instead, a
white solid is formed, which does not dissolve well in the concentrated acid.
Nitrogen oxides do not trigger a reaction, even when these are present, the
reaction with the hydrazine does not set off.
EXPERIMENT 70
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Sodium hypophosphite does not react with 68% nitric acid when mixed in the
cold. When the mix is heated somewhat, then the reaction suddenly sets off and
is self-sustained.
EXPERIMENT 71
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Hexavalent chromium is reduced to trivalent chromium by hypophosphite, but
there is no further reduction to chromium(II).
EXPERIMENT 72
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Thallium(I) ion is fairly easily oxidized to thallium(III). In neutral aqueous
solutions, this ion hydrolyzes to a dark hydrous oxide, which forms a compact
precipitate. The dark oxide easily can be dissolved in nitric acid, such that a
colorless solution of thallium(III) nitrate is formed in nitric acid.
Thallium(III) ion forms an ochre/yellow color with ferricyanide ion, which is
stable at low pH, but at high pH this decomposes, giving a yellow solution of
ferricyanide and a dark brown suspension of hydrous thallic oxide.
EXPERIMENT 73
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Methylene chloride is capable of extracting nitric acid from its aqueous
solution.
EXPERIMENT 74
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Peroxodisulfate ion gives a deep brown complex with silver ions in nitric acid.
Oxone (peroxomonosulfate) does not give such a complex, actually, it quickly
destroys such a complex.
EXPERIMENT 75
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Concentrated nitric acid does not react violently with hydrazine at low
temperature. When the acid is heated, then a reaction occurs. It is remarkable
that such a strong oxidizer does not immediately decompose hydrazine.
EXPERIMENT 76
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Bismuth(III) in aqueous nitric acid solution does not form a precipitate with
bromate ion.
End of results for 'nitric acid'