Monthly Archives: March 2012

E8 Waste

1. Two methods of waste disposal are landfill and incineration. (a) Outline each of the above methods Incineration is the process of burning a material so that only ashes remain, and landfill is method of solid waste disposal in which … Continue reading

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E7 Soil

(i) State a main constituent of SOM. A main constituent are decayed plant, non living organic (ii) Explain with reference to the structure above, how SOM can increase the soil quality, in terms of the following Provision of nutrients: It … Continue reading

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E6 Water Treatment

review questions; Waste water can contain metal ions such as chromium. Chromium ions can cause damage to the liver and kidneys. Chromium ions can be removed from water by chemical precipitation using hydroxide ions. (a) Assuming chromium is present as … Continue reading

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E5 Dissolved Oxygen in Water

review questions; water purity is often assessed by reference to its oxygen content. (a) Outline the meaning of the term biochemical oxygen demand (BOD). [2] The amount of oxygen needed to decompose organic matter (in water sample); in a specified time, at … Continue reading

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E4 Ozone Depletion

review questions; (c) discuss the advantages and disadvantages of using hydrocarbon in place of CFC’s. [2] The advantage is that the bond between C-Cl is not weak, it does not release Cl atoms. The disadvantage is that, it has the … Continue reading

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E3 Greenhouse Effect

review questions; (a) two of the major greenhouse gases in the atmosphere are methane andc carbon dioxide. State two other major greenhouse gases. H2O(Water Vapor), N2O (Nitrous oxide, dinitrogen monoxide), Chlorofluorocarbons (CFCsCCl2F2), Ozone (O3) (b) Discuss which two gases from … Continue reading

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E2 Acid Deposition

review questions; (a) Explain using an equation why rain falling in unpolluted air is acidic with a pH of about 5.7. [2] Because it contains dissolved CO2 CO2 + H2O        H2CO3  / CO2 + H2O         H++ HCO3– (b) “Acid rain” … Continue reading

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