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प्रश्न
Green plants use carbon dioxide for photosynthesis and return oxygen to the atmosphere, even then carbon dioxide is considered to be responsible for greenhouse effect. Explain why?
उत्तर
CO2 gas is confined to the troposphere only and it forms nearly 0.03 per cent by volume of the atmosphere. With the increased use of fossil fuels, a large amount of carbon dioxide gets released into the atmosphere. Excess of carbon dioxide in the air is removed by the green plants and this maintains an appropriate level of it in the atmosphere. Green plants require carbon dioxide for the process of photosynthesis and which in turn emits oxygen, thus maintaining the balance in nature. Deforestation and the burning of fossil fuels increase the level of carbon dioxide, and this disturbs the balance in the atmosphere. The increased amount of carbon dioxide in the air is mainly responsible for global warming.
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संबंधित प्रश्न
Statues and monuments in India are affected by acid rain. How?
Which of the following gases is not a green house gas?
The gaseous envelope around the earth is known as atmosphere. The lowest layer of this is extended upto 10 km from sea level, this layer is ______.
The acids present in acid rain are:
(i) Peroxyacetylnitrate
(ii) H2CO3
(iii) HNO3
(iv) H2SO4
Acid rain is known to contain some acids. Name these acids and where from they come in rain?
Match the pollutants given in Column I with their effects given in Column II.
| Column I | Column II |
| (i) Phosphate fertilisers in water | (a) BOD level of water increases |
| (ii) Methane in air | (b) Acid rain |
| (iii) Synthetic detergents in water | (c) Global warming |
| (iv) Nitrogen oxides in air | (d) Eutrophication |
Assertion (A): The pH of acid rain is less than 5.6.
Reason (R): Carbon dioxide present in the atmosphere dissolves in rain water and forms carbonic acid.
Match List - I with List - II.
| List - I | List - II | ||
|
(a) |
\[\ce{2SO2(g) + O2(g) -> 2SO3(g)}\] | (i) | Acid rain |
| (b) | \[\ce{HOCl(g) ->[hv] \overset{\bullet}{O}H + \overset{\bullet}{C}l}\] | (ii) | Smog |
| (c) | \[\ce{CaCO3 + H2SO4 -> CaSO4 + H2O + CO2}\] | (iii) | Ozone depletion |
| (d) | \[\ce{NO2(g) ->[hv] NO(g) + O(g)}\] | (iv) | Tropospheric pollution |
Choose the correct answer from the options given below.
The gas released during anaerobic degradation of vegetation may lead to ______.
Assertion (A): Ozone is destroyed by CFCs in the upper stratosphere.
Reason (R): Ozone holes increase the amount of UV radiation reaching the earth.
