OCR A Jun 2013 Paper 2 Q1

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Answer all the questions. 1 Crude oil is a complex mixture of many hydrocarbons. Crude oil is processed by the petroleum industry to make fuels and petrochemicals. (a) The straight-chain alkane, A, is present in crude oil. A has molecules with ten carbon atoms. (i) What is the molecular formula of A?[1] (ii) B is a branched-chain isomer of A. Draw the skeletal formula of a possible structure for B. Name your structure. name[2] (iii) The branched-chain isomer B has a lower boiling point than the straight chain alkane A. Explain why.[2] (b) A chemist heats a pure sample of C15H32 in the presence of a catalyst. A reaction called cracking happens. (i) Construct an equation to show the cracking of C15H32.[1] (ii) When cracking takes place, a large number of products are formed. Suggest why a large number of products are formed.[1]OCR 2013<br />
 (c) The petroleum industry processes straight-chain alkanes into cyclic hydrocarbons. For example, octane can be processed into a cyclic hydrocarbon and hydrogen. (i) Suggest the structure of this cyclic hydrocarbon. (ii) Why does the petroleum industry process straight-chain alkanes into cyclic hydrocarbons?[1] [Total: 9] [1]OCR 2013 Turn over<br />

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