C1.4.3 Hydrocarbon fuels Version 2.0 Copyright © AQA and its licensors. All rights reserved. Using Exam pro items to support successful outcomes • Learners will be able to test their progress against learning outcomes using questions from past AQA GCSE examinations Version 2.0 Copyright © AQA and its licensors. All rights reserved. 1. Foundation The Great London Smog of 1952 • Smog is a mixture of smoke and fog. Use the information from this graph to answer the following questions. Version 2.0 Copyright © AQA and its licensors. All rights reserved. Questions 1. Explain why it is thought that sulfur dioxide caused additional deaths in December 1952 2. After the peak on 10th December the death rate stayed higher than normal. Why do you think this happened? 3. Can you be certain that sulfur dioxide was the cause of death? 4. It is important to burn fuels in a good supply of air Do you agree with this statement. Remember to include the products of complete and partial combustion in your answer. Version 2.0 Copyright © AQA and its licensors. All rights reserved. Answers- Key Points 1. 2. 3. On the 8th December it shows both peaks ( rise in deaths and sulfur dioxide levels) happening together. Some people will already have inhaled sulfur dioxide and will be ill as a result The lines for rise in deaths and sulfur dioxide levels are well matched but at the same time the levels of smoke also increased. The smoke could have caused the extra deaths or made the effect of the sulfur dioxide worse. 4. • • • Carbon monoxide is made when the supply of oxygen is low- carbon monoxide is toxic. When the supply of air is good then water vapour and carbon dioxide is produced-this is a greenhouse gas If the fuel contains sulfur, sulfur dioxide will still be produced however much air is available. This causes acid rain Version 2.0 Copyright © AQA and its licensors. All rights reserved. 2 Foundation C1 Jan 12, 4 Version 2.0 Copyright © AQA and its licensors. All rights reserved. Version 2.0 Copyright © AQA and its licensors. All rights reserved. Mark scheme Q Answer Extra Information Mark 2 (i) the amount of ethanol used) increases from (1970) to 1989 Then it decreases from 1989 ( to 2000) If no year(s) or incorrect year(s) indicated then max 1 Correct year(s) only needs to be indicated to gain full marks accept values in range 19871992 1 (ii) Any one from • • • • • • 1 Brazil had more oilfields Cost of crude oil had decreased Cost of ethanol/sugar(cane) had increased Demand for ethanol/sugar (cane) had increased Availability of ethanol/sugar(cane had decreased Climate change affects growing sugar cane Accept availability of land to grow sugar (cane) had decreased Total Version 2.0 1 Copyright © AQA and its licensors. All rights reserved. 3 3. Higher C1 Jan 12, 6 Version 2.0 Copyright © AQA and its licensors. All rights reserved. Version 2.0 Copyright © AQA and its licensors. All rights reserved. Version 2.0 Copyright © AQA and its licensors. All rights reserved. Mark scheme- Higher Q Answer i Any two from • • • • • ii Extra Information 2 Same volume/amount of acids Concentration of acids Temperature Same surface area/size/mass/amount of calcium carbonate Same measuring equipment Any three from • • • • • • Mark (after about 4 minutes) the sulfuric acid stops reacting or nitric acid continues to react (initially) the reaction with sulfuric acid is faster (the reaction stops) because calcium sulfate is a solid (the reaction continues) because calcium nitrate is soluble/in solution/aqueous Because the calcium sulfate prevents the sulfuric acid reacting with the calcium carbonate (the rate is faster) because sulfuric acid contains 2 hydrogens Accept more CO2 with nitric acid at any time after 4 mins Allow sulfuric acid produces a solid Allow nitric acid produces an (aqueous) solution Total Version 2.0 Copyright © AQA and its licensors. All rights reserved. 3 5