Most vehicle fuels contain hydrocarbons obtained from crude oil.

1. (a)(i)State the name of the type of reaction that hydrocarbons undergo when being used as fuels.[1]
2. (a)(ii)Write an equation for the reaction of octane, C8H18, as a fuel, as in (a)(i).[2]
3. (b)(i)Name this process.[1]
4. (b)(ii)Draw the repeat unit of the polymer that is produced from but-2-ene.[2]
5. (b)(iii)Name the type of polymerisation that occurs during the production of the polymer in (ii).[1]
6. (c)Gases produced in internal combustion engines include carbon monoxide, oxides of nitrogen such as NO2, and unburnt hydrocarbons. These gases are removed from the exhaust before they can enter the atmosphere.
7. (c)(i)State what is used to remove these gases from the exhaust.[1]
8. (c)(ii)Write one equation to show how both carbon monoxide, CO, and nitrogen dioxide, NO2, are removed from the exhaust.[1]
9. (c)(iii)State the environmental consequence of allowing unburnt hydrocarbons to enter the atmosphere.[1]
10. (d)Vehicle fuels are treated to remove sulfur. If sulfur is present in a fuel when it is burned, SO2 is produced and may be released into the atmosphere where it can form acid rain.
11. (d)(i)Acid rain can contribute to breathing difficulties. Identify two other consequences of acid rain in the atmosphere.[2]
12. (d)(ii)NO2 is involved in the production of acid rain from SO2. Give two equations which describe how acid rain is formed by the action of NO2 with SO2.[2]
13. (d)(iii)NO2 is described as a catalyst during this process. Explain, with the use of an appropriate equation, why NO2 is described as a catalyst.[2]

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