Gcse Chemistry

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G C S E S P E C I F I C AT I O N GCSE Specification Chemistry For exams January 2012 onwards For certification June 2013 onwards GCSE Specification Chemistry 4402 This specification is published on the AQA website (aqa.org.uk). We will let centres know in writing about any changes to the specification. We will also publish changes on our website. The version on the website is the definitive version; this may differ from printed versions. Further copies of this specification booklet are available from: AQA Logistics Centre (Manchester), Unit 2, Wheel Forge Way, Ashburton Park, Trafford Park, Manchester, M17 1EH Or, you can download a copy from the AQA website: aqa.org.uk Copyright © 2011 AQA and its licensors. All rights…show more content…
Many useful materials can be produced from crude oil. Crude oil can be fractionally distilled. Some of the fractions can be used as fuels. Biofuels are produced from plant material. There are advantages and disadvantages to their use as fuels. Fuels can come from renewable or non-renewable resources. Subject Content Candidates should use their skills, knowledge and understanding to: ■ evaluate the impact on the environment of burning hydrocarbon fuels Additional guidance: Knowledge and understanding of the products of burning hydrocarbon fuels and the effects of these products is limited to those named in the subject content for this section. Candidates may be given information and data about other fuels and their products of combustion for comparison and evaluation in the examinations. Candidates should know and understand the benefits and disadvantages of ethanol and hydrogen as fuels in terms of: ■ ■ ■ ■ consider and evaluate the social, economic and environmental impacts of the uses of fuels 3…show more content…
This process is fractional distillation. c) Some properties of hydrocarbons depend on the size of their molecules. These properties influence how hydrocarbons are used as fuels. boiling points viscosity flammability. C1.4.3 Hydrocarbon fuels Additional guidance: a) Most fuels, including coal, contain carbon and/or hydrogen and may also contain some sulfur. The gases released into the atmosphere when a fuel burns may include carbon dioxide, water (vapour), carbon monoxide, sulfur dioxide and oxides of nitrogen. Solid particles (particulates) may also be released. Candidates should be able to relate products of combustion to the elements present in compounds in the fuel and to the extent of combustion (whether complete or partial). No details of how the oxides of nitrogen are formed are required, other than the fact that they are formed at high temperatures. Solid particles may contain soot (carbon) and unburnt fuels. b) The combustion of hydrocarbon fuels releases energy. During combustion the carbon and hydrogen in the fuels are oxidised. 18 GCSE Chemistry for teaching from September 2011 onwards (version 1.0) Additional
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