Chemistry of typical
The typical non-metals have their own
characteristic chemistry, which really is very
different, when compared with typical metal chemistry.
Especially the halogens and chalcogens have interesting
List of fully worked out experiments:
and/or refining of sulphur. Sulphur is
dissolved in hot toluene, and on cooling down,
nice needle-like crystals of sulphur are formed.
selenium. In this experiment, some
black/grey selenium is dissolved in nitric acid
and the solution of selenous acid then is
reduced with a solution of a sulfite. This
results in formation of a red precipitate of
selenium. This red selenium is another allotrope
of selenium. In the same experiment, some pieces
of zinc are plated with a thin layer of
species of tellurium, selenium and sulphur.
A comparison is made of what happens when
tellurium, selenium and sulphur are added to
concentrated sulphuric acid and heated.
Tellurium and selenium form remarkable and
really uncommon cationic species. Sulphur does
not react with sulphuric acid, but in oleum the
element sulphur also gives a remarkable cationic
properties of halogen complexes of tellurium
in oxidation state +4. At very low pH,
tellurium in oxidation state +4 forms remarkable
compounds with the halide ions. The heavier the
halogen, the more stable the complex and the
more intense the color. All of these complexes,
however, are very prone to hydrolysis in aqueous
for making a miniature electrolysis cell for
chlorate production. This is not really an
experiment, it is a description of how one can
setup a nice small electrolysis cell, suitable
for making chlorates from chlorides. The good
working of this cell is demonstrated for making
potassium chlorate and cesium chlorate.
Colored gases -
chlorine and chlorine dioxide . Two experiments are performed. In
one of them, chlorine gas is made from dilute
hydrochloric acid and calcium hypochlorite. In
the other, chlorine dioxide is made from sodium
chlorate and concentrated hydrochloric acid. The
chlorine dioxide has a really intense yellow
'combustion' of acetylene in chlorine gas
. Acetylene gas, made from reacting
water with calcium carbide (a.k.a. 'carbid) is
bubbled into an erlenmeyer, filled with chlorine
gas. This results in violent explosions inside
the erlenmeyer. Spectacular, but also somewhat
chemiluminiscence with chlorine swimming pool
chemicals. Hydrogen peroxide (30%) is
added to some solid swimming pool chemicals.
This gives a clearly visible red
chemiluminiscence. This experiment is
particularly interesting, when done in a dark
bromine/chlorine and phosphorus . When red phosphorus is immersed
in an atmosphere of bromine vapor or chlorine
gas, then it ignites and keeps burning in the
bromine vapor or chlorine gas.
Example of interhalogen
compounds . Iodine and chlorine
react with each other and form so-called
interhalogen compounds, iodine monochloride and
iodine trichloride. The dry iodine monochloride
does not react with magnesium, but when it is
wetted a little, then a violent reaction starts.
bromine and aluminium . When a
small piece of aluminium is put in liquid
bromine, then after some induction period, a
very violent reaction starts, with fire and
polyhalide salt of potassium. Potassium
iodate reacts with concentrated hydrochloric
acid, giving chlorine gas. From the solution,
long needles of potassium tetrachloroiodate(III)
can be isolated. This is an example of a
polyhalide compound of rubidium. Rubidium
is known to form polyhalide compounds fairly
easily, more so than the lighter alkali metals
(see experiment above). In this experiment such
a compound is prepared. During the preparation a
beautiful crystalline precipitate is formed.
reaction with bromate. This is the
classical Belousov-Zhabotinsky reaction, an
oscillating reaction. Although it is well-known,
it remains one of the most beautiful and
remarkable demonstrations. The reaction, shown
in this page, is based on the oxidation of
malonic acid with bromate ions, with
manganese(II/III) or cerium(III/IV) as a
potassium bromate. Potassium bromate can
be synthesized fairly easily from the easy to
obtain potassium bromide by means of
electrolysis, especially, when a tiny amount of
a chromate or dichromate is added. This makes an
interesting and hard to obtain energetic
chemical accessible for a large group of home
Bromine from OTC
compounds. Bromine is prepared from
standard swimming pool chemicals. Only a very
small amount of chromate or dichromate is
needed, but this can be made easily as well (no
need to isolate and purify this).
isolation of phosphorus tribromide . Phosphorus tribromide is prepared
by means of careful addition of red phosphorus
to bromine. By means of distillation the product
potassium periodate. Potassium periodate
is prepared by leading chlorine gas through a
solution of potassium iodate and potassium
hydroxide. Some acid is used to precipitate all
of the periodate as the very sparingly
Synthesis of sodium
orthoperiodate. Sodium orthoperiodate is
prepared by leading chlorine gas through a
solution of sodium iodide and sodium hydroxide.
The nice thing of this synthesis is that it
allows one to make periodate without needing
access to any special chemicals besides the easy
to obtain sodium iodide.
self-ignition of mix of periodic acid and red
phosphorus. Some red phosphorus and
periodic acid are mixed. After a while, this mix
suddenly self-ignites and a plume of fire and
smoke is produced.
halates, unstable compounds . Ammonium bromate and ammonium
iodate are prepared and it is demonstrated how
easily and violently they decompose on slight
heating. This is a nice and fairly spectacular
experiment, but it should not be scaled up.
Formation of dense
smoke from bromine and ammonia . Ammonia gas and bromine vapor
react with each other, giving dense smoke of
ammonium bromide. In this experiment, some
bromine vapor is poured into an erlenmeyer,
containing dilute ammonia gas. The result is
-- purple and yellow. This is a surprising
experiment. A mix of potassium periodate and
ammonium thiocyanate is ignited. Initially, the
smoke, produced from the burning mix, is purple,
but this smoke quickly turns golden yellow.
between molten nitrite and iodate. Some
potassium hydrogen diiodate (double salt of
potassium iodate and iodic acid) is mixed with
sodium nitrite and the mix is heated. This gives
a mix of nitrogen dioxide and iodine vapor. This
mix has a beautiful color.
iodoform. A small amount of iodoform is
heated in a test tube, and it is shown how this
decomposes, giving purple vapor of iodine.
Reaction in gas phase.
Nitrogen monoxide and oxygen are prepared and
mixed by setting up an apparatus with two glass
bottles. As soon as the gases mix, a deep brown
gas is formed.
Fun with red
cabbage. Red cabbage juice is treated with
solutions of different pH. Surprising colors can
be obtained in this way, much more than the
well-known pink/rose to violet/blue colors,
which one knows from the kitchen.
of water -- detonating gas. Water is
decomposed by means of electrolysis of a dilute
sulphuric acid solution. The resulting gases are
mixed and the impressive explosive power of this
gas mix is demonstrated.
of acetate and formiate. Acetate and
formiate are electrolysed and based on the
observations in this experiment, the net
reactions are derived. A demonstration of what
can be achieved with a combination of careful
observation and reasoning.
oxidation of sugar by concentrated sulphuric
acid. This is a spectacular experiment, in
which sugar is charred by concentrated sulphuric
acid and a lot of black foam, smoke and noise is
red phosphorus to white phosphorus . This is a write-up on how one can
convert red phosphorus to white phosphorus. The
process described here is suitable for making a
few grams of white phosphorus per batch.
Color of the
flame of burning gases. Different gases
are collected in a test tube, sucked in a
syringe, and then ignited. Many different flame
colors can be obtained from different gases.
Some flame colors are remarkable, such as
pink/rose and grey.
properties of chlorine dioxide . The brightly colored chlorine
dioxide gas is prepared and ignited. This
results in a nice and quite spectacular
chlorine dioxide, initiated by presence of
ammonia . Another experiment,
which demonstrates the danger of chlorine
dioxide. This experiment shows how chlorine
dioxide can be brought to explosion, simply by
adding a few drops of household ammonia.
reaction . Nitrous oxide is
mixed with carbon disulfide vapor and this mix
is ignited. This results in a very spectacular
reaction with bright light and an impressive
and properties of ammonium periodate. A
simple experiment, in which ammonium
(meta)periodate is made. This compound explodes
when it is heated.
reaction between hydrazine and periodate.
In this experiment it is demonstrated that
hydrazine and periodate react extremely
violently and so much heat is produced that
iodine escapes as vapor, even from aqueous
what happens when hard water is heated.
This experiment is a nice and safe demonstration
and explanation of what happens when hard water
different oxohalogenate ions. Several
oxohalogenate compounds are added to a
concentrated solution of hydrazine
dihydrochloride. In many cases this leads to a
reaction, some of them being very violent. A
comparison is made of the reactivity of the
different oxohalogenate ions at room
phosphine in chlorine gas . In this experiment some phosphine
is prepared, and the gas is bubbled in an
atmosphere of chlorine, resulting in
self-ignition of the gas and contraction of gas
volume. This demonstrates the high reactivity of
chlorine but also the high reactivity of
phosphine. This is a remarkable and spectacular
experiment, which makes a good demo.
aspects of selenium chemistry . The element selenium has some
interesting properties in combination with
sulfide and bromide. It can form strongly
colored species, which are stable in aqueous
solution and can be studied without the need of
Formation of a
self-igniting gas from fine sand powder and
magnesium . Magnesium metal and
finely powdered sand are reacted to form
magnesium silicide, which in contact with dilute
acids produces self-igniting silane gas. This is
a spectacular, but somewhat dangerous
cationic iodine species in oleum. Iodine
is dissolved in oleum and the formation of a
blue cationic species is demonstrated. Iodine is
brought to oxidation state +½, which is very
special for iodine.
Preparation of tin(IV)
iodide, a volatile covalent compound. Tin
and iodine are made to react in a suitable
solvent for iodine. Under these conditions the
interesting compound tin(IV) iodide is formed,
which can easily be isolated. Some properties of
this compound are shown.
decomposition of hydrazine perchlorate and
fairy-like sparkles. A small quantity of
hydrazine perchlorate is prepared and this
compound is heated, leading to a peculiar
fairy-like sparkling when heating is not too
strong and violent deflagration on stronger
decomposition of an organic perchlorate salt.
A perchlorate salt of a basic organic amine is
prepared and it is shown how this salt
decomposes violently when it is ignited.
explosive reaction. Hydroxylamine and
bromate, when mixed with each other at high
concentration, do not react immediately. There is
a lead time of tens of seconds, and after that
lead time there is a sudden very fast reaction,
which only takes milliseconds.
and purification of ammonia. Ordinary
household ammonia is concentrated and purified
by heating the liquid, driving out the gas and
leading that gas through distilled water. This
process can be used to make very pure ammonia at
a higher concentration than the plain household
and raw material with some nice results and ideas:
sesquisulfide, stunning change of its appearance.
Black antimony sesquisulfide is dissolved in
concentrated hydrochloric acid. When the liquid is
diluted, then the dissolved antimony(III) hydrolyses
again and with sulfide, present in solution, hydrated
yellow antimony sequisulfide is formed. The anhydrous
compound is black, te hydrous compound is yellow.
experiments with organic swimming pool chlorine.
A set of different experiments with swimming pool
chlorine, in the form of trichloro isocyanuric acid
(TCCA) or its sodium salt. With copper(II) ions, a
remarkable precipitate is formed, with ammonia, a
spectacular reaction occurs, with production of lots
of mix of potassium chlorate and red phosphorus.
Some potassium chlorate and red phosphorus are mixed
and the mix is set off, simply by tapping on it with a
smooth glass rod.
of a nitration runaway. A nice and funny
experiment. Some isopropyl alcohol is added to a mix
of nitric acid and sulphuric acid. As soon as the
alcohol reaches this mix, an exceedingly violent
reaction occurs, in which a big plume of red/brown
nitrogen dioxide is formed.
- Green fire with
boron compound. Some dimethyl amine borane
complex is burned. This is a flammable solid, which
smoothly burns with a bright green flame.
of nitrogen oxides, NOx. This experiment nicely
demonstrates that nitrogen dioxide is in equilibrium
with its dimer, dinitrogen tetroxide. On heating, a
flask, filled with nitrogen dioxide becomes much
darker and on cooling down the gas mix in the flask
becomes very light. A nice demonstration, which is
really suitable for demonstrating equilibria.
- Properties of
halogens and interhalogen compounds. Different
halogens are mixed with each other. This gives rise to
formation of interhalogen compounds. These
interhalogen compounds have nice interesting colors in
the gas phase, and with the help of these a set of new
beautifully colored gases can be made.