Q.1. Name the different regions of the atmosphere alongwith their altitudes.
AnswerAnswer: Troposphere (0-10 km, stratosphere (10-50 km), mesosphere (50-85 km), thermosphere (85 – 500 km).
Q.2. In what regions of the atmosphere, the temperature increases with altitude and in which regions it decreases?
AnswerAnswer: Temperature increases with altitude in stratosphere and thermosphere while it decreases in troposphere and mesosphere.
Q.3. What gas leaked to bring havoc in Bhopal tragedy?
AnswerAnswer: Methyl isocyanate (MIC).
Q.4. What is the %age of CO2 in the pure dry air?
AnswerAnswer: About 0. 032%.
Q.5. Name three gases which are major air pollutants.
Q.6. What is the most important sink of CO pollutant?
AnswerAnswer: Soil micro–organism.
Q.7. What is the compound formed when CO combines with blood?
AnswerAnswer: Carboxyhaemoglobin (HbCO).
Q.8. What is anoxia or asphyxiation?
AnswerAnswer: Acute oxygen starvation in the body (due to CO poisoning) is called anoxia or asphyxiation.
Q.9. How are NO and NO2 formed in the atmosphere?
AnswerAnswer: NO is formed due to reaction between N2 and O2 during lightning or combustion of fossil fuels. It is further oxidized to NO2.
Q.10. How are fuel gases from industries freed from oxides of nitrogen and sulphur?
AnswerAnswer: By scrubbing them with conc. H2SO4 or with alkaline solutions like Ca(OH)2 and Mg(OH)2.
Q.11. What is chlorosis?
AnswerAnswer: Slowing down the formation of chlorophyll in plants due to presence of SO2 as pollutant is called chlorosis.
Q.12. What is the size range of particulates?
AnswerAnswer: 5 nm to 500,000 nm.
Q.13. What type of aromatic compounds are present as particulates in the air?
AnswerAnswer: Polycyclic aromatic hydrocarbons (PAH).
Q.14. Who are the people who usually suffer from ‘black lung disease’ and who are those who suffer from ‘white lung disease’?
AnswerAnswer: Coal miners suffer from black lung disease and textile workers suffer from white lung disease.
Q15. How particulates help in the cloud formation?
AnswerAnswer: They act as nuclei for cloud formation.
Q.16. Which zone is called ozonosphere?
Q.17. Which main compounds are causing damage to ozone layer?
AnswerAnswer: NO and freons.
Q.18. Which gaseous species are present in the mesosphere and thermosphere?
AnswerAnswer: Gaseous ions like NO+, O2+, N2+, O+ and atoms of N and O.
Q.19. Which disease is caused due to hole in the ozone layer and why?
AnswerAnswer: Ultraviolet rays will reach the earth after passing through the hole and cause skin cancer.
Q.20. What is the composition of ‘London smog or reducing smog’?
AnswerAnswer: Fog of H2SO4 droplets deposited on the particulates.
Q.21. In which season and of what time of the day, there is ‘London smog or reducing smog’ ?
AnswerAnswer: In winter during the morning hours.
Q.22. What is the nature of ‘London smog’ ?
Q.23. In which season and what time of the day, there is photochemical smog?
AnswerAnswer: In summer, in the afternoon.
Q.24. Which acids are present in the acid rain?
AnswerAnswer: H2SO4, HNO3 and HCl.
Q.25. Name two important sinks of CO2 .
AnswerAnswer: Oceans (which dissolve it) and plants (which use it for photosynthesis).
Q.26. What is marine pollution?
AnswerAnswer: Pollution of sea water due to discharge of wastes into it is called marine pollution.
Q.27. What type of pollution affects the sea–birds?
AnswerAnswer: Oil water pollution.
Q.28. What are the main sources of thermal pollution?
AnswerAnswer: Thermal power plants and nuclear plants.
Q.29. Why COD is preferred over BOD ?
AnswerAnswer: COD can be found in a few minutes whereas BOD requires at least 5 days.
Q.30. What is humification?
AnswerAnswer: The decomposition of organic material (leaves, roots etc.) in the soil by microorganism to produce humus is called humification.
Q.31. What should be the tolerable limit of fluoride ions in drinking water? What happens if it is higher than 10 ppm ?
AnswerAnswer: 1 ppm or 1 mg dm–3. Higher concentration is harmful to bones and teeth.
Q.32. Name any four methods for waste management.
AnswerAnswer: Recycling, burning, incineration and sewage treatment.
Q.33. What is the nature of ‘photochemical smog’?
AnswerAnswer: It is oxidizing in nature.
Q.34. Name of source of energy which does not create pollution.
AnswerAnswer: Sun is source of energy which does not create pollution.
Q.35. What are PCBs?
AnswerAnswer: PCBs are polychlorinated biphenyls
Q.36. What are polar stratospheric clouds (PSCs)?
AnswerAnswer: Polar stratospheric clouds. PSC’s are formed over Antarctica. They are of two types:
Type I clouds contain some solidified nitric acid trihydrate (HNO3, 3H2O) formed at –77°C.
Type II clouds contain some ice, formed at –85°C These clouds play an important role in ozone depletion.
Q.37. What is meant by polar vortex?
AnswerAnswer: Polar vortex. When polar stratospheric clouds are formed over Antarctica during winters, stable wind patterns in the stratosphere are called polar vortex which encircle the continent.
Q.38. What is effect of excess of SO42– ion in drinking water?
AnswerAnswer: Excess of SO42– in drinking water (>500 ppm) may cause a laxative effect.
Q.39. Write the name of gas produced in Mathura refineries which can damage the great historical monument “Taj Mahal”?
AnswerAnswer: Sulphur dioxide.
Q.40. What type of radiations are absorbed by CO2 in the atmosphere?