Worksheet 3.1
ENVIRONMENTAL SCIENCE PUBLISHED FOR EVERYBODY ROUND THE EARTH
Ozone and its chemical properties
| T 1 |
Draw the second resonance structure of the ozone molecule below. |
| T 2 |
Explain why the O3 molecule has dipole character and compare it with a CO2 molecule and a H2O molecule. |
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T 3 |
If ozone reacts with an alkene (ozonolysis), the alkene molecule is cracked at the C=C double bond. The products of the reaction are two carbonyl compounds. Write down and name the products of the ozonolysis of: a) 2-butene b) 2-methyl-2-butene |
Some properties of ozone:
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l T boiling = -112.5° C |
l poorly water-soluble |
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l T melting = -251.4° C |
l soluble in organic solvents i.e. in CF2Cl2 |
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l µ = 0.49 D |
l toxic |
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l bluish color |
l O2/O3 (w (O3) < 10% stable below 100° C |
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l characteristic smell |
l O3(l), O3(s) explode during contact |
strong oxidizing agent:
examples of oxidation reactions with ozone:
| T 4 |
Can oxidation by ozone proceed better at high or low pH? Give reasons for your answer using the information in the box above. |
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T 5 |
Iodide ions can also be oxidized by molecular chlorine. Write down the reaction scheme and explain the difference to reaction 1 in the box above. |
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T6 |
In atmospheric cloud droplets, ozone oxidises sulphurous acid (sulphur dioxide in water). This oxidation is most efficient at high pH levels.
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