> Français > Climate Encyclopaedia > haute atmosphère > Bases > 2. Trou d'ozone > * Exercices 2
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Higher Atmosphere
Basics |
2. Ozone and light
Worksheet 2 |
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Ozone is very important in our stratosphere, because of its characteristics in connection with a special and harmful quality of light. The experiment (E) will give you some impressions about that. With the help of the tasks (T) it will be easy to understand the important effect of ozone in the stratosphere.
The equipment, pictured in fig. 1, is made to form ozone of oxygen in the same way as it is formed by the Chapman- cycle in the stratosphere. A special lamp is necessary inside (e.g.: a middle pressure mercury vapor lamp).
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fig. 1 formation of ozone © 2003 Seesing, Tausch; Duisburg
A: fluorescent lamp ballast
B: ____________lamp
C: reactor
D: oxygen
E: ozone
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Explain briefly, why a normal incandescent lamp is not useful to form ozone.
Enter the necessary characteristic of lamp in the legend of fig.1 to "B:".
You need a darkenable room and following materials for the experiments:
Mention: The chemicals oxygen and ozone (and if used the short waved UV-light) are harmful. Experiment carefully and protect yourselves! (Cover the UV-light-reaction chamber with aluminium foil, to protect your eyes.) |
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equipment to form ozone
fluorescent screen, or a TLC-foil with fluorescent indikator F254
UV-hand lamp ( λ=254 nm)
glass tubes to pass through the ozone
aluminium-foil (to darken, it depends on the kind of equipment to form ozone you use) |
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F: fluorescent screen (λ=254nm)
G: ozone ( oxygen mixture)
H: UV-hand lamp (λ=254nm)
© 2003 Seesing, Tausch; Duisburg
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Form ozone and drive it in short pulses through a glass tube between the fluorescent screen and te UV-hand lamp. (alternatively: click on the picture and regard a short film.[OzoneAndLight.avi 192kB])
Describe briefly, what you can see, if you drive ozone (content mixture of gases) in short pulses troug the glass tube between the fluorescent screen (λ=254 nm) and the UV-lamp (λ=254 nm).
What is the reason of this observation?
Why is this characteristic very important for the life on earth? |
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worksheet 1: StratBasicOzoneAndLightk1.pdf (206kB) |
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worksheet 1 solution: StratBasicOzoneAndLightSolk1.pdf (218kB) |
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movie: OzoneAndLight.avi (192kB) |
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