OCR A Jan 2010 Paper 2 Q1

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Answer all the questions. 1 Kerosene is used as a fuel for aeroplane engines. (a) Kerosene is obtained from crude oil. Name the process used to obtain kerosene from crude oil and explain why the process works.[2] (b) Some of the hydrocarbons in kerosene have the formula C10H22. (i) What is the name of the straight chain hydrocarbon with the formula C10H22?[1] (ii) Draw the skeletal formula of one branched chain isomer with the formula C10H22. [1] (iii) Explain why the straight chain isomer of C10H22 has a higher boiling point than any of its branched chain structural isomers.[2] (iv) Explain why the straight chain isomer of C10H22 is converted by the petroleum industry into its branched chain isomers.[1]OCR 2010<br />
 (c) When kerosene burns in an aeroplane engine very little carbon monoxide, CO, is formed but a significant amount of nitrogen monoxide, NO, is formed. (i) Construct the equation to show the complete combustion of C10H22.[2] (ii) Suggest, with the aid of an equation, how NO is formed within an aeroplane engine.[1] (d) NO is a radical and contributes towards ozone depletion in the stratosphere. (i) What is a radical ?[1] (ii) One of the processes leading to the breakdown of ozone in the stratosphere can be represented by the following two equations. NO(g) + O3(g) NO2(g) + O2(g) NO2(g) + O(g) NO(g) + O2(g) What is the role of the NO in this process?[1] (iii) Ozone in the stratosphere is broken down to make O2 and O. Describe and explain how the concentration of ozone in the stratosphere is maintained.[2] (iv) Why is it important to life on the Earths surface that the concentration of ozone in the stratosphere is maintained?[1]OCR 2010 [Total: 15] Turn over<br />

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