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15 Cards in this Set
- Front
- Back
- 3rd side (hint)
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What is the composition of air? |
Nitrogen = 78% Oxygen= 21% Noble gases=0.97% Carbon dioxide= 0.03% |
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What are some air pollutants and its effects? |
1) Carbon monoxide (CO)(Source: incomplete combustion of petrol in cars) - reacts with haemoglobin in blood to form carboxyhaemoglobin - reduces ability to transport oxygen to rest of the body 2) sulfur dioxide (SO2)(Source: Burning of fossil fuels and volcanic eruptions) - forms acid rain - leads to bronchitis - irritation of eyes and lungs 3) oxides of nitrogen (NO, NO2) (Source: due to lightning, car engines) - forms acid rain- leads to bronchitis - irritation of eyes and lungs 4) unburnt hydrocarbons (Source: car exhaust fumes) - reacts with nitrogen oxides to form ozone - they are carcinogens so they cause cancer 5) methane (Source: animal matter decaying) - causes global warming as it is a greenhouse gas 6) ozone - forms photochemical smog, which irritates eyes and lung |
Remember that there is 6 pollutants |
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How is acid rain formed? |
Acid rain is formed when acidic air pollutants such as sulfur dioxide and nitrogen dioxide react with water in the atmosphere |
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How does sulfur dioxide lead to acid rain? |
- Sulfur dioxide dissolves in water to sufulrous acid (H2SO3) SO2 (g) + H20(l) ------> H2SO3 (aq) - In the presence of oxygen in the air, sulfulrous acid is slowly oxidised to form sulfuric acid |
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How does nitrogen dioxide lead to acid rain? |
- In the presence of oxygen and water, nitrogen dioxide is slowly converted to nitric acid 4NO2 (g) + 2H20 (l) + O2 (g) -------> 4HNO3 |
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Which compounds can destroy the ozone layer? |
Only carbon compounds containing both chlorine and fluorine can destroy the ozone layer |
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How do CFCs destroy the ozone layer? |
-In the presence of UV radiation, CFCs decompose to become chlorine atoms.
-Chlorine atoms react with ozone molecules in the stratosphere to form chlorine oxide and oxygen, destroying the ozone layer. |
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RECAP: What's oxidation and reduction? |
Oxidation: - gains oxygen - loses hydrogen - loses electrons Reduction: - Loses oxygen - gains hydrogen - gains electrons |
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how are oxides of nitrogen formed in car engines? |
Due to complete combustion of fuels in a car engine, the temperature is very high. So, the nitrogen and oxygen in the air combine to form nitrogen monoxide. |
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which gas is the only toxic gas? |
Carbon monoxide |
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What is helium used for? |
Filling weather or advertisement balloons, airships |
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What is argon used for? |
- used to fill tungsten bulb, provides an inert environment that prevents oxidation of the filament - Used to provide an inert atmosphere for certain processes such as the welding of steel |
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What is argon used for? |
- used to fill tungsten bulb, provides an inert environment that prevents oxidation of the filament - Used to provide an inert atmosphere for certain processes such as the welding of steel |
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What is neon used for? |
Used to make lights and advertising signs |
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What is xenon used for? |
Used in vehicle headlamps |
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