mail.tajen.edu.tw
cylin66mail.npic.edu.twChemical Education Journal (CEJ),
Vol. 13, No. 2 /Registration No. 13-18 /Received December 2, 2009.
URL =
http://chem.sci.utsunomiya-u.ac.jp/cejrnlE.html
mail.tajen.edu.tw
cylin66mail.npic.edu.tw
Abstract
The main purpose of this paper is to design some interesting
microscale experiments, and to demonstrate the microscale hydrogen
gun, the microscale hydrogen / oxygen water rocket, and the explosion
apparatus of microscale hydrogen / oxygen mixed for chemistry
teaching. Plastic syringes, three-way plastic stopcocks, electronic
gas igniter, and some simple and small amounts of materials are
used in these designs. The hydrogen is produced by Mg and HCl,
and the oxygen is produced by MnO2 and
H2O2. Both hydrogen
and oxygen are produced by using Fang's multiple microscale gas
generators and collected in the 10 mL plastic syringe individually.
In addition, the chemicals used in above microscale experiments
can be recycled. These simple microscale apparatus can be carried
out easily to make students have fun in demonstration.
Keywords: demonstration, microscale experiments, multiple
microscale gas generator, hydrogen gun, water rocket
A. Design of Fang's multiple microscale gas generator
B. The steps for preparing oxygen
C. The steps of preparing hydrogen
A. The design and demonstration of the microscale hydrogen gun
B. The design and demonstration of hydrogen / oxygen water rocket
C. The Demonstration with the microscale exploder of mixed hydrogen/oxygen.
There are more than 10,000 primary, junior high schools and senior high schools at present in Taiwan. We really want to reduce the waste from chemical experiments at school. So the researchers find out the wonderful methods to deal with this problem. It is very important and useful that adopting the wonderful methods to minimize the environmental pollution for waste treatment (3+1) R, i.e. reduce, recycle, reuse, and refuse. The design of microscale experiments could meet the environmental protection principles such as green consumption with low pollution, recycling, and energy province. The design of microscale experiments also could offer students more opportunities to do the hands-on experiments. And the design also can strengthen students' interest in learning science and understanding the importance of environmental protection(1-6).
| Plastic syringes (10 mL) | x 2 |
| Three-way plastic stopcock | x 1 |
| Electronic gas igniter | x 1 |
| Plastic dropper (5 mL) | x 1 |
| Manganese oxide (MnO2) | 5 g |
| Hydrogen peroxide solution (20 % H2O2) | 20 mL |
| Hydrochloric acid solution (3 M) | 10 mL |
| Hot melt glue gun | x 1 |
| Hot melt glue gem | x 1 |
1. Prepare two 10 mL-plastic syringes and one 3-way plastic
stopcock.
2. Joint two plastic syringes on the side of 3-way plastic stopcock
individually (Fig. 1).
Fig.1 The design of Fang's multiple microscale gas generator.
1. Open the piston of plastic syringe and put about 5 grams
of manganese oxide (MnO2) as catalyst in
the plastic syringe.
2. Take about 10 mL of 20% hydrogen peroxide solution by another
plastic syringe and connect both syringes according to Fig.
1.
3. Pull the 10 mL of 20% hydrogen peroxide solution slowly to
the other plastic syringe containing the MnO2.
4. Oxygen is produced when hydrogen peroxide solution touch the
catalyst manganese oxide, and oxygen is collected in the other
plastic syringe.
1. Open the piston of plastic syringe and put about 1-cm length
of magnesium (Mg) strip in the plastic syringe.
2. Take about 10 mL of 3 M hydrochloric acid solution by another
plastic syringe and connect both syringes according to Fig.1.
3. Pull the 10 mL of 3 M hydrochloric acid solution slowly to
the other plastic syringe containing the metal Mg.
4. Hydrogen is produced when hydrochloric acid solution touch
the metal Mg, and it is collected in the other plastic syringe.
1. The design of the microscale hydrogen gun
a. Buy a small electronic gas lighter (Fig.
2) from the supermarket.
b. Exhaust all the gas from the bottom of electronic gas lighter.
c. Dig a hole in the center of the film box. (The diameter of
the hole is about 0.5 cm).
d. Insert the head of the lighter into the bottom of film box
about
2 cm and then fix them with hot melt glue gem.
e. The microscale hydrogen gun is shown in Fig.
3.
Fig. 2 Electronic gas lighter (left) and during lighting (right).
Fig. 3 The microscale hydrogen gun.
2. The demonstration of using the hydrogen gun
a. Open the cover of the film box from the microscale hydrogen
gun.
b. Make the film box upside down and put about 5 mL hydrogen into
the empty film box from plastic syringe.
c. Close the cover of the film box immediately.
d. Fire the microscale hydrogen gun by pressing the hand switch,
shown in Fig. 4.
e. The hydrogen in the film box will explode, and the plastic
cover of the film box will be launched with a very loud sound.
Fig. 4 Press the hand switch to fire the microscale hydrogen gun.
Prepare the hydrogen and the oxygen from the Fang's multiple gas generator in the plastic syringe individually, and collect them in one plastic syringe by mixing hydrogen and oxygen with 2:1 by volume ratio, and then put the mixing gases into the head of the microscale water rocket.
1. The design of the microscale hydrogen/oxygen water
rocket
a. Prepare a head of a plastic dropper (keep 1 cm from the head
of a plastic dropper), shown in Fig.
5 (left).
b. Fix the four pieces of plastic in the symmetrical position
of the head of microscale hydrogen/oxygen, shown in Fig. 5 (right).
Fig. 5 The head of microscale hydrogen/oxygen water rocket
2. The design of improving electronic lighter as a launcher.
a. Prepare a multiple electronic gas lighter (Fig.
6) and exhaust all the gas. b. Connect two pieces of wire
(about 5 cm long) out of the electronic gas lighter , shown in
Fig. 7 (right).
c. Finish the improving electronic lighting as a launcher, shown
in
Fig. 7 (left).
Fig. 6 Multiple electronic gas lighter
Fig. 7 Improving electronic lighter as a launcher
3. The demonstration of the microscale hydrogen/oxygen water rocket.
a. Put 6 mL of hydrogen and 3 mL of oxygen in the 10 mL plastic
syringe individually.
b. Two plastic syringes insert one side position of 3-way stopcock,
individually (Fig.1).
c. Pull 6 mL of hydrogen to 3 mL of oxygen with the Fang's multiple
microscale gas generator. Then the hydrogen and oxygen are mixed
in one syringe by volume ratio 2:1.
d. Pull 4 mL of the mix of hydrogen and oxygen slowly into the
head of microscale water rocket (Fig.8).
e. Prepare water and put the water in the head of water rocker.
Leave 1 mL of water in the head of water rocket.
f. Insert the front two wires of the improving electronic lighter
into the head of microscale water rocket carefully, shown in Fig. 9.
g. Hold the improving electronic lighter and keep the head on
45 degrees of angles of elevation (Fig.
10 left).
h. The head of water rocket is fired and exploded through fire
the lighter, and the water of the water rocket will produce one
small fire (Fig. 10 right) and spray
water at once.
Fig. 8 Pull the mixed gas of hydrogen and oxygen to the head of microscale water rocket.
Fig. 9 Insert the two wires of the launcher into the head of microscale water rocket.
Fig. 10 Hold the improving electronic launcher with hand, and launch it with the angle of elevation of 45o
1. Prepare a 6- holes groove which is shown in Fig.
11.
2. Put a detergent solution into one of 6-holes groove completely.
3. Utilize gas mixed apparatus (Fig.
1) to mix 6 mL hydrogen with 3 mL oxygen for a 2:1 hydrogen/oxygen
(9 mL).
4. Connect the plastic syringe which contains 9 mL mixed gas of
hydrogen and oxygen to a inject needle.
5. Inject the mixed gas of hydrogen and oxygen into the detergent
solution in 6-holes groove slowly.
6. The surface of the detergent solution is filled with chemical
foams which contain the mixed gas hydrogen and oxygen (2:1) (Fig. 12).
7. Light a match to near the foam (Fig.
13) and then explode with a very loud sound.
Fig. 11 A 6- holes groove.
Fig. 12 Inject the mixed gas of hydrogen and oxygen into the detergent solution in 6-holes groove from the plastic syringe.
Fig. 13 Light the foam with match and then explode with a very loud sound.
The creative microscale experiments play important roles in the chemistry instruction. The experiments are not only interesting but also creative for students' learning. These creative designs include microscale hydrogen gun, microscale hydrogen and oxygen water rocket and microscale exploder hydrogen/oxygen, etc. In addition, these creative microscale experiments strengthen the function of education, environmental protection and economic benefit through teaching and learning. So these designs of microscale experiments constructed by Fang in Taiwan are becoming very practical and economic green experiments.
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