0801xObendrauf

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Viktor Obendrauf 
 
University of Graz, Institute of Chemistry 
A-8010 Graz, Schubertstraße 1 
e-mail: [EMAIL] 
 
MORE SMALL SCALE HANDS ON EXPERIMENTS FOR EASIER TEACHING 
AND LEARNING  
 
„A pretty experiment is in itself often more valuable than twenty formulae extracted from our 
minds. Albert Einstein (1879-1955)  
 
Neurobiological research proves that lasting learning is closely linked to emotions. A ‚pretty’ 
reaction arouses emotions just like a dangerous or a dangerous looking experiment.  
Many colleagues can confirm that most of the students remember nothing better than 
‚beautiful‘ or ‚dangerous‘ experiments. Through aesthetically arrange d and really exciting 
experiments they frequently grasp the associated theoretical concepts more easily. 
Of course, definitely dangerous experiments must be cancelled in school. Chemical education 
should be as safe as possible for teachers and students. But chemical demonstrations which 
are classified as possibly dangerous by the students can support learning with emotions. Using 
microscale techniques many potentially dangerous reactions can be performed in a safe and 
inexpensive way. 
There exists no scientific definition for aesth etic science phenomena. But there exists a 
general consensus that chemical demonstrations  and students activities can be designed more 
or less pretty. Classical examples of aesthetic reactions and/or aesthetically presented 
processes are various coloured structures and crystallisations  in Petri dishes, projection 
cuvettes and on microscope slides. For many people pyrotechnic effects are beautiful. Even 
the burning down of a simple ice candle can create emotions. Many  burning ice candles 
arranged as pyrotechnic numbers and letters ar e much more than a simple reaction between 
heated titane particles with oxygen of the air.    
For many students, unclear experimental arrangements are not elegant or even beautiful. They 
want to pick up the experiment and the concepts  behind it as fast as possible. A simple and 
clear experimental procedure without many fixi ng stands and clamps, that is focused on a 
microscale level and enlarged with modern el ectronic equipment for large auditoriums, can 
sometimes improve both the aesthetics and safety of potentially dangerous experiments. 
For many teachers and lecturers, experimental procedures are not elegant and pretty when 
they require expensive and time-consuming preparations and exhausting clean ups with lots of 
waste. Going microscale can improve the aesthe tics and the safety of chemical reactions by 
reducing the time, costs and waste.  
Six years ago it was a big honour a nd also a great pleasure for me  to be invited to give a 
plenary lecture during the 16 th ICCE in Budapest dealing with  small scale and microscale gas 
reactions. The audience agreed that specia l video techniques can be very useful for 
performing time-saving and cost-s aving small scale reactions in  big lecture-th eatres without 
polluting the environment. By enlarging the improvised low-cost-equipment with modern 
digital video projection techni ques the properties of very poi sonous gases can be safely 
demonstrated without a fumehood. The experimental topics duri ng the lecture in Budapest 
were: the generation of chlorine, acetylene,  hydrogen, hydrogen sulp hide, sulphur dioxide, 
ammonia and oxygen, the reactions between sodi um and chlorine, hydrogen and chlorine, 
chlorine and acetylene, hydrogen and oxygen, hydrogen sulphide and sulphur dioxide.

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The same low cost equipment and digital video techniques — enriched with some special 
products from any European supermarket and  a couple of improved ideas to generate, store 
and dispose small amounts of hazardous gases — should be used for the lecture in Seoul. 
In any case, the discussed small scale experi ments are not designed for combination with 
video techniques. For normal classrooms, the ph ilosophy is that a badly arranged experiment 
in a fumehood or behind a safety shield is less  impressive for creating emotions than a small 
scale portable apparatus which needs no fixing stands and allows the lecturer to perform and 
repeat the experiments closer to the students. 
Detailed instructions and figures dealing with the special materials necessary for these low 
cost gas generations and small scale gas reactions are described in the book of abstracts of the 
16
th ICCE 2000 in Hungary. These materials have successfully been used for more than ten 
years in Europe and should be described again for those colleagues and teachers in Asia who 
have had no chance to pick up these experimental suggestions until now.  
 
Material © for the low cost gas generation and gas reactions [1,2,3]: 
(a) 1 test-tube Schott Fiolax® 16/160 mm, bulged mouth. 
In this test tube the gases are generated. The rather thin but fireproof 
material heats up the substances inside in a very short time; if it is 
necessary, this substance can be cool ed down again in a water bath or 
with tap water in a few seconds. 
(b) 1 soft rubber-stopper (Verneret18D) with 1 or 2 syringe needles (1.2/40 mm) 
pierced through the stopper as shown in figure 1. 
The tips of the needles in the stopp er must be cut off as shown in 
picture 2. The blunt needles in the stopper work as micro steel tubes 
with luer connections. Needles without tips are no longer needles. 
Even with differently strong acids, the stopper works for many months 
without having to replace the tubes. 
(c) 1 disposable syringe 2 ml (e.g. Braun ®) 
This syringe is used as a dropping funnel for liquids. The plunger 
(without washer) must be difficult to move. For this property a rough 
surface inside the syringe prepared with fine iron wool is very useful. 
To suck up the needed liquid it is useful to have the chemicals in 10-20 ml narrow 
mouthed bottles. As a result, even concentr ated hydrochloric acid  or concentrated 
ammonia solution is no problem outside the fume hood. To avoid contact with the adhered 
chemicals after filling, the syringe must be cleaned outside with a paper towel or rinsed in 
a beaker with water or with tap water. Then the syringe can be placed tightly in the luer 
connection steel tube of the special stopper. 
Figure 1
(d) 1 syringe 20 ml, eccenctric luer conus (ONCE ®) This syringe is used to collect and store 
the generated gas and stoichiometric mixtures. To avoid pressures that are too high in the 
apparatus, the plunger must be easily movable when compared to the 
2ml-syringe. Therefore the washer at the end of the plunger must be 
slightly greased with high boiling silicon oil. 
Figure 2
(e) 1 10 ml syringe without a plunger, firs t filled with activated charcoal 
granular and then closed with 1 r ubber stopper with 1 syringe needle 
in it as shown in figure 1 
This device is very useful to avoid excessively hazardous gases 
coming out of the gas generator when  the 20 ml syringe is filled and 
no more gas is needed.

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(f) 20 ml disposable syringe (ONCE® ) with inserted piezoelectric 
sparker (figure 3) 
This device, built from a 20 ml disposable syringe and a piezoelectric 
lighter allows one to collect variou s explosive mixtures of gases to 
show the stoichiometric reactions  in the syringe directly. Con-
structing the device: A nail is heated in a flame, this hot nail is used 
to melt a small hole in the syringe, a stereo wire with blank metal 
ends is inserted through the hole and the connection is sealed with 
hot-glue as shown in figure 3. The other end of the wire must be 
connected to the piezoelectric sparker so that it works (see figure 3). 
(g) Steel tubes 1.2/40 mm with luer connections (syringe needles with 
cut tips). The thin steel tubes with the luer connections and the blunt 
end serve for jets, e.g. either a) to light hydr ogen or acetylene pressed out from a syringe  
or b) to jet the wanted gas into a test-tube or into another syringe. The steel tubes placed  
the soft rupper stoppers or serving for jets  work for many months without destroying 
in corrosion even in contact with concentrated acids. To avoid corrosion during storage, 
the steel tubes must be rinsed inside with water and dried with air. Th is procedure  
consumes only a couple of seconds: Using a 20 ml syri nge press some water through the 
tubes and dry the tubes inside by sucking and pressing air through them.    
Figure 3
(h) Steel tubes 0.8/120 mm with luer connections (syringe needles with cut tips) 
The long syringe needles can be used as a reaction tube with a very big (catalyzed or not 
catalyzed) surface inside e.g. to heat a 
stoichiometric mixture of sulphur 
dioxide and  
oxygen or as catalyst tube for the 
catalytic reaction between ammonia 
and oxygen (Ostwald procedure see 
figure 4) etc. 
The modified and strongly heated long 
needle can also be used to decompose 
gaseous compounds e.g. ammonia or 
for thermolysis reactions (e.g. paraffin oil to gaseous hydrocarbons). 
8 ml NH  + 10 ml O32
NOxPt
Figure 4
(i) Micro burner 
Portable, with piezoelectric sp arker, refillable with ligher butane, burner time not limited, 
size of the flame adjustable, works in each position (see figure 4) 
(j) 15-20 cm long  pieces of insulator from a stereo  wire (copper wire removed), used as thin 
plastic tubes  
(k) 100 ml disposable syringe with catheter 
connection (Figure 5  
This syringe is used to collect, store and weigh 
larger amounts of gases. The catheter 
connection fits to the lu er connection of smaller 
syringes and to the outlet of a special wine 
bottle opener which works very comfortably 
with commercial chargers filled with carbon 
dioxide for soda bottles or nitrous oxide for 
whipped cream.  
Figure 5

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(l) Mobile small scale ozone generator  
Using a silcon tube a normal small scale 
oxygen gas generator is connected to a 
test tube which contains a thin glass tube 
filled with a salt solution (e.g.copper 
sulphate). This solution is in contact 
with a small high voltage device (stun 
gun, see figure 6). The second 
connection of the hi gh voltage device 
leads to a sheet of copper or brass 
outside the test tube, so that discharges 
can be produced from outside the test 
tube to the thin glass tube inside the test 
tube. Pure oxygen inside the test tube 
can be converted to  ozone partially. 
Ozone mixed with normal oxygen can 
be collected in a 20ml syringe (see fig 6) 
 
 
(m) Explosion Limits Film Can 
A Fuji® film can (with a snap cap) equipped with a 
piezoelectric device can be used to check the explosion 
limits of very low boiling organic liquids such as
acetone or ethyl acetate.  The  volume of  the film can is 
about 33 cm
3. 
A very small but accurate amount of completely 
evaporated acetone or et hyl acetate should give a 
mixture within the explosion limits. 
Example:  Explosion limits of acetone  (LEL:  with  
60 g acetone/m3 air = about 2 mg acetone/33 cm3.  UEL: 
310 g acetone/m3 air = 10 mg acetone/33 cm3. 
1 very small drop of acetone  is about 7-9 mg which 
means that 1 drop of acetone completely evaporated and 
mixed with the air inside the closed film can is within the 
explosion limit. 2 drops or mo re give a mixture which is 
too rich. 
Special lighter fuel (not lighter gas) such as ZIPPO® 
lighter fuel consists of octane and familiar hydrocarbons 
with a proper vapour pressure of about 0,0147 bar so that 
excess liquid in the closed film cannot produce too rich 
mixtures. Example: The calcu lated amount of oxygen in 
the film can is about 6,9 cm
3. The volume x of the 
vapour in the closed film can with excess liqui d in it should not be more than about 0,5 
cm3. (x cm 3 : 0,0147 bar  =  33cm 3  : 1,0147 bar) Compared to 6,9 cm 3 is the mixture is 
the hydrocarbon vapour near the stoichiometric mixture: HC : O2 = 0,5 : 6,9 = about 1:14. 
(C8H18 + 12,5 O2 → 8 CO2 + 9 H2O).  It is possible to produce many harmless explosions 
in the can after replacing the air and closing the container.    
Figure 6
Fuji Film Can with Cap
Piezoelectric
device in a 
2ml syringe
Distance of the
wire ends inside::
ca. 3 - 4 mm Figure 7

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MORE EXAMPLES OF EXPERIMENTS WHICH ARE WELL KNOWN BUT ARE 
NEWLY DESIGNED, SMALL SCALE AND DONE WITHIN 3-5 MINUTES: 
 
1.  Photolytic reaction between hydrogen and chlorine 
Figure 8The air in the chlorine gas generator is replaced by 
generating chlorine, the air in  the hydrogen gas generator 
is replaced by generating hydrogen. To make sure that the 
flash will work with the mixture every time, the hydrogen 
can be cleared of hydrochlor ic gas. Connect the 10 ml 
syringe filled with charcoal with the hydrogen gas 
generator and replace the air in the charcoal by hydrogen. 
Then connect the 20 ml syringe  filled with 10 ml pure 
chlorine with the luer conus  connection of the charcoal 
filled syringe. Add 10 ml purified hydrogen (figure 8). 
The syringe with the collected gas mixture is placed 
vertically using a cut needle on a foam base as a stand. If 
the sheet of the flash covers the attached 20ml syringe 
completely, the reaction will start every time without 
removing the UV filter from the flash (see figure 8). 
 
2. Generation of NOx using copper and nitric acid, properties of NO, NO2, N2O3, N2O4 
After replacing the air in the gas generator the 
well-greased special 20 ml syringe is used to 
collect the generated NO
x. A 10 ml syringe 
without a plunger, first filled with activated 
charcoal granular and then closed with a rubber 
stopper, pierced by one syringe needle, 
functions as a portable fumehood, after the the 
20 ml syringe has filled up with the poisonous 
mixture. With the generated mixture in the 20 
ml syringe the solubility of NO
2 in water, the 
equilibrium between NO 2 and N 2O4, the 
formation of N 2O3 and a couple of other 
properties of the gas mixture can be shown 
easily.  
HNO3
NOx
NOx
NO
Cu
Figure 9
Using a gas generator for car bon monoxide the catalytic reac tion between CO and NO to N 2 
and CO2 can be formed in a test tube which contains pieces of a normal car catalyst. 
3.  Instant chemistry: Micro-ampoules as pressure-resistant permanent preparations [4] 
Thick sided glass ampoules often serve as containers for liquified gases and highly evaporable 
liquids. These chemical-physical „permanent pr eparations“ have the advantage that they 
demonstrate various phenomena without spending too much time on preparation and cleaning 
up. If you reduce the volume of the ampoules to  a few micro-litres, the ampoules containing 
various substances can be sealed, given some  care and experience, without the help of a 
professional glassblower. Modern soldering torches with accurate flames make the 
preparation of such micro-ampoules (2-3 mm in diameter!) a lot easier. 
In spite of their thin glass th e tiny tubes resist enormous pre ssure so that you can even seal 
liquified carbon dioxid e or laughing gas. This makes it possible to demonstrate the 
phenomenon of critical temperatures of vari ous substances in a su rprisingly easy way. For 
example, the critical temperature of liquified nitrous oxide, which is 36.5°C, can be reached

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with the help of a hairdryer within seconds, so that the liquid in side the ampoule suddenly 
disappears. After all, the corresponding crit ical pressure amounts to 72.6 bar. Similar 
experiments can be carried out with liquifi ed carbon dioxide (criti cal temperature 31.6°C, 
critical pressure 73.8 bar). A 
slight cooling ends this 
simultaneity of liquid and vapor 
and the liquid state is seemingly 
re-formed from nothing. Liquid, 
gaseous and – if liquid nitrogen 
is available – even solid chlorine 
can thus be produced just as 
quickly as the temperature 
dependent equilibrium between 
NO
2 and N 2O4. If the mixture 
contains NO and NO 2,the deep 
blue N 2O3 can be permanently 
preserved in quite a spectacular 
way even at room temperature (traditionally this  is only possible through cooling). Above its 
melting point (-100.1°C) N
2O3 decomposes according to the following equilibria: 
N2 (l)
6 mm glass tube
2  mm glass tube
Figure 10
N2O3  ' NO + NO2
2 NO2  '  N2O4
If you do not keep on cooling the ampoule after sealing it, 
the light blue solid substance will melt, first into a deep blue 
liquid state which, because of the extremely high pressure, 
does not even disappear at r oom temperature (according to 
the principle of Le Chatel ier). Heating up the micro-
ampoule with a hairdryer enables you to demonstrate the 
concentration of the brown gaseous state caused by the 
intensified production of NO
2 from N2O4 within seconds. 
In addition to the described phenomena, micro- ampoules enable you to demonstrate lots of 
other temperature dependent chemical-physical processes („Instant Chemistry“!) [4]. 
Even in very large lecture halls, they can easily be visualized by means of modern video 
cameras 
4. A wine bottle opener as a source for N2O – the „barking dog“ without NO and CS2 [6] 
N2O (laughing gas) in high pressure steel am poules is used to produce whipped cream. 
Special wine bottle openers work with the sa me type of steel ampoules containing carbon 
dioxide. Therefore those wine bottle openers 
can also serve as source for N
2O so that many 
experiments involving N 2O can be designed as 
„Instant Chemistry“ examples [5,6,7,8,9] 
E.g.: Using the wine bottle opener it is possible 
to fill a wide mouthed 1 litre glass bottle with 
laughing gas within one minute. Instead of 
poisonous CS
2 normal rum (80% ethanol) is 
evaporated at hot tap water temperatures so that 
the noise and the blue flash of the famous 
„barking dog“ can be performed with material 
bought exclusively from the super-market. The 
nice reaction may follow this reaction path:

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C2H5OH + 4 N2O → 4 N2 + 2 CO  +  3H2O 
2 CO    +   2 N2O    →         2 N2  +  2 CO2  
_________________________________________________________________________________________________________________________________________ 
C2H5OH + 6 N2O → 6 N2 + 2 CO2 + 3H2O 
 
5. Microscale dry ice production and microscale liquefied laughing gas [10]. 
 Two exciting and pretty examples of gases are well known in the kitchen: carbon dioxide and 
laughing gas. Both laughing gas and carbon dioxide are simple substances in every day life. 
Both laughing gas and carbon dioxide are stored in very similar looking steel cartridges for 
whipped cream chargers and for soda siphon char gers. Both gases can be  used in sufficient 
amounts for chemical education in a special wine bottle opener. [3,4,5] 
Compared to carbon dioxide nitrou s oxide is a gas with very similar physical properties (see 
table 1). Many similar physical material data e.g.  density, molar mass, solubility in water and 
critical temperature can be demonstrated in a very simple way. Experimental stuff from 
schools combined with special supermarket products is sufficient.  
Table 1 
 N2O CO2
Structure N=N=O O=C=O 
Molecular mass 44,01 u 44,01 u 
Litre mass 1,997g/l 1,977g/l 
Melting point -90,8°C -57°C (5,2 bar) 
Boiling point -88,8°C -78,5°  (sublimation) 
Critical temperature 36,5°C 31,06°C 
Critical pressure 72,6 bar 73,83 bar 
Critical density 0,457g/l 0,464 g/l

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The chemical properties and the physiological effects of nitrous oxide and carbon dioxide 
with iso-electronic structures of its molecules are completely different.  
Laughing gas is not only used to make whipped cream. Many students know that nitrous 
oxide could be used for sniffing. Of  course it is used in  hospitals for anaest hesia, it is further 
more well known as an very effective oxidizer  in combustion engines. Using small amounts 
of laughing gas the properties as  an oxidizing agent can be dem onstrated in various simple 
and timesaving ways [4-7]. 
On the other hand a soda siphon cartridge contains  carbon dioxide which can be used as a fire 
extinguishing gas. A special re cipe to produce small amounts dry ice from one single soda 
siphon charger gives us the chance to show the sublimation and the trip le point in a small 
syringe even for a big audience [6-10]. 
 
6. The basis of a safety match [11]  
Safety matches use a match head that is mainly KClO 3, struck against the match box surface, 
which consists of non-toxic red phosphorus (about 50%). Placed outside the matchbox, 
instead of in the match-head, the match can only be ignited through friction with the red 
phosphorus panel. This is the basis for the safety match, wh ich can be shown without any 
laboratory equipment if only microscale amounts of the potentially dangerous chemicals are 
involved. The reaction on a microscale level, stoichiometry, calculation, and safety goggles 
prevent possible accidents. 
Concerning the equation with 
0,00010 mol (about 12,3 mg 
finely powdered) KClO
3 and 
0,00012 mol (about 3,7 mg 
dried phosphorous) a nice 
flash can be produced in 
theory. To be sure that the red 
phosphorous will react 
completely with the solid 
oxidizing agent and cannot 
burn on the skin with the 
oxygen of the air, excess 
KClO
3 (about 40 mg) is 
necessary and essential!  
      
7) Pictures can say more than words  
The described material for the low cost gas generation for many 
microscale gas reactions can be st ored in two or three plastic 
video cassette boxes. Using this equipment more than hundred 
different and context based reactions can be performed.   
It should be noted that particular emphasis is laid on the 
described test-tubes, syringes and ‘soft rubber’ stoppers. The 
material used in these procedures is essential for being on the 
safe side with successful results. If somebody uses other test-
tubes, disposable syringes and normal ‘red’ or black rubber 
bungs as available in most sc ience education suppliers’ 
catalogues the described techniqu e for a mobile low cost gas 
generation without a fume hood will probably fail. The 
following pictures should show th e wide range of possibilities.

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The examples have been found to be partic ularly useful in demonstrating potentially very 
dangerous reactions relatively safely on a very sm all scale but still with  a spectacular result. 
Chemical demonstrations and la b activities should be done as small as necessary, but not as 
small as possible. 
7.1. Inverse flames 
Is oxygen able to burn? This question could ar ise during the inverse flame experiment which 
was very famous in the 
19th century (see figure 
below). The potentially 
dangerous experiment is 
dealing with pure oxygen 
and pure hydrogen. 
In a pure hydrogen 
atmosphere pure oxygen 
delivered from a small 
tube seems to burn with a 
nice flame, if the reaction 
between the elements can 
be started before a very 
dangerous mixture can be 
formed. The reaction on a 
normal scale would be 
dangerous. This may be 
one of the reasons why 
the inverse flame experiment  disappeared out of the 
sourcebooks for chemistry teachers. 
    
 
 
Using the described low cost material© with sp ecial test tubes, stop pers and syringes the 
inverse flame experiment can also be performed with pure chlorine delivered from a syringe 
with a small steel tube (needle with cut dip) on it. Chlorine seems to burn in pure hydrogen.

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7.2. Chemical vapour deposition (CVD) modelling experiment [12] 
 
Silane is generated by the reaction of magnesium  silicide with 1 M HCl (aq) in the special 
small test tube. Before this reaction can be initiated the air in the gas generator can be 
replaced easily using a cooling spray (FHC). The generated silane can burn only at the end of 
the glass tube as shown in the picture above. Through heating the glass tube the delivered gas 
will be decomposed inside so that a thin f ilm of silicon appears. The produced hydrogen can 
be collected and detected. 
 
Using a microflame the thin film silicon can be heated for demonstrating the semiconducting 
properties of the layer (CVD). In addition the self ignition of silane is a nice experience.

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7.3. Self ignition of P2H4 [13] 
 
With a commercial rodenticide containing 28 % 
of Ca3P2 the self ignition of very poisonous PH3 
contaminated with P 2H4 can be shown similar 
to the self ignition of silane. Small amounts of 
chemicals in the small gas generator reduce the 
danger and the time for the preparations. 
 
7.4. Chlorine and bromine without a fumehood, photolytic reaction with pentane [14]

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7. 5. Sparks from a piezoelectric device for at least 20 various explosive mixtures [3, 15] 
 
 
Warning: The short description of the experiments shown in the pictures and figures above is 
only useful for this abstract. If somebody wa nt to perform these potentially dangerous 
experiments, the original literature [1-15] with detailed descriptions and helpful references for 
a safe troubleshooting is strongly recommended. 
    
 
 
Literature: 
 
[1] V. Obendrauf, Low Cost Gas Generation for Small Scale Hands on Experiments, 16th ICCE, Budapest, 2000, 
Book of abstracts 
[2] V. Obendrauf, Experimente mit Gasen im Minimaßstab. ChiuZ 1996, 30 (3) 118 
[3] V. Obendrauf, Die Low-Cost-Lachgas-Kanone. PdN-ChiS 1999, 48 (3), 35 
[4] V. Obendrauf,  Gläserne Hochdruckbehälter im Mikromaßstab, PdN-Ch 2000, 49 (5) 4 
[5] V. Obendrauf, Lachgas auf Knopfdruck, Chem.Sch.(Salzbg.) 2001, 16 (2) 4 
[6] V. Obendrauf, Der „Bellende Hund“ m. Mitteln des Alltags, Chem.Sch.(Salzbg.) 2001, 16 (4) 11 
[7] V. Obendrauf, Sichtbarer Kohlenstoff aus unsichtbarem CO2, Chem.Sch. (Salzbg.) 2002, 17 (1) 13 
[8] V. Obendrauf, Von der Sahnekapsel zur Modellrakete, Chem.Sch. (Salzbg.) 2003, 18 (3) 12 
[9] V. Obendrauf, 40th IUPAC Conference, Beijing 2005, Keynote Lecture, Book of Abstracts 2005 
[10] V. Obendrauf, Trockeneis aus dem Supermarkt, Chem.Sch.(Salzbg.) 2005, 20 (4)  6 
[11] V. Obendrauf, Amorces, Partyknaller, Knallkorken, Pyrotechnisches Spielzeug, PdN-Ch 2003, 52 (5)  22 
[11] V. Obendrauf, Inverse Flammen, „Kann Sauerstoff brennen?“ Chem.Sch.(Salzbg.) 2005, 20 (1)  9 
[12] V. Obendrauf, Chemical Vapour Deposition, Microscale-Experimente mit Silan. PdN-ChiS 2005, 54 (1), 43 
[13] V. Obendrauf, Phosphan – Historische Experimente aktuell  Chem.Sch.(Salzbg.) 2006, 21 (2), 11 
[14] V. Obendrauf,  Small Scale Hands On zum rotbraunen Gift T+ (Brom). Chem.Sch.(Salzbg.) 2006, 21 (1) 11 
[15] V. Obendrauf, Feuerzeugbenzin im Arbeitstakt. Chem.Sch.(Salzbg.) 2000, 51 (3) 8

This article was reproduced from the Proceedings of the 19th International Conference on Chemical Education, August 12-17, 2006, Seoul, Korea, pp. 10-21, with permission of the Organizer.   Additional note by the author It is an overview what is possible with my special gas generators. It is also a conclusion about the advantages of microscale chemistry.  The crucial point is to use the materials described in particular for the equipment.  Otherwise the colleagues could be disappointed. Different syringes have different properties. If dangerous or poisonous gases are involved it is necessary to follow the instructions in detail.