10.3. Air quality and climate
A subsection of Chemistry, 0620, through 10. Chemistry of the environment
Listing 10 of 389 questions
Nitrogendioxide, NO2, is an atmospheric pollutant and is formed in car engines. Explain how nitrogendioxide is formed in car engines. Nitrogendioxide causes respiratory problems. State one other adverse effect of nitrogendioxide. Nitrogendioxide emissions can be reduced by adding an aqueous solution of urea, (NH2)2CO, to car exhaust gases. The heat of the exhaust gases breaks down the urea into simpler substances. Name the type of reaction which occurs when a substance is heated and breaks down into simpler substances. One molecule of urea breaks down to form one molecule of ammonia and one other molecule. Complete the chemical equation to show the formula of the other molecule formed in this reaction. (NH2)2CO → NH3 +  State the test for ammonia. test observations  The ammonia formed reacts with nitrogendioxide to form nitrogen and water. Balance the equation for this reaction. NO2 + NH3 → N2 + 12H2O State how the equation shows that the nitrogen in nitrogendioxide is reduced. This reaction is a redox reaction. State the meaning of the term redox. 135moles of urea, (NH2)2CO, is stored in the tank of a car. Calculate the mass, in kg, of the stored (NH2)2CO.  mass of (NH2)2CO = kg  Another oxide of nitrogen formed in car engines is nitrogenmonoxide, NO. A catalytic converter removes NO by reacting it with a gas formed by incomplete combustion of the fuel. Two non‑toxic gases are formed. Name the gas formed by incomplete combustion of the fuel. Name the two non‑toxic gases formed. and ���������������������������������������������������������������� 
0620_m22_qp_42
THEORY
2022
Paper 4, Variant 2
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This question is about gases found in clean, dry air and gases found in polluted air. Name one gas found in clean, dry air which contributes to global warming. State the percentage of nitrogen in clean, dry air. Name the substance used to remove sulfurdioxide in flue gas desulfurisation. Nitrogendioxide, NO2, is formed in car engines. Name the equipment in a car exhaust used to remove the NO2 formed in car engines. All gases diffuse. Choose from the list of formulae the gas which diffuses most quickly. Draw a circle around your answer. CO CO2 CH4 NO2 SO2  Explain your answer to . State one adverse effect of carbon monoxide on human health. Carbon dioxide, CO2, is a reactant in photosynthesis. Name the two products of photosynthesis. and ������������������������������������������������������������������� Complete the dot-and-cross diagram in Fig.1.1 for a molecule of CO2. Show outer shell electrons only. C O O  
0620_m23_qp_42
THEORY
2023
Paper 4, Variant 2
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Questions Discovered
389