Chemistry

2892 WordsOct 14, 201412 Pages
1. (a) The diagram below represents the industrial fractional distillation of crude oil. (i) Identify fraction A. (ii) What property of the fractions allows them to be separated in the column? (2) (b) A gas oil fraction from the distillation of crude oil contains hydrocarbons in the C15 to C19 range. These hydrocarbons can be cracked by strong heating. (i) Write the molecular formula for the alkane with 19 carbon atoms. (ii) Name the type of reaction involved in cracking. (iii) Write an equation for one possible cracking reaction of the alkane C16H34 when the products include ethene and propene in the molar ratio 2:1 and only one other compound. (4) (Total 6 marks) 2. A compound of carbon, hydrogen and nitrogen contains…show more content…
(4) (Total 8 marks) 7. There are five structural isomers of the molecular formula C5H10 which are alkenes. The graphical formulae of two of these isomers are given. Isomer 1 Isomer 2 Draw the graphical formulae of two of the remaining alkene structural isomers. (Total 2 marks) 8. (a) Petrol engines in cars produce a number of pollutants which can be removed by catalytic converters. Discuss this statement, indicating what the pollutants are, how they arise and how they are removed as efficiently as possible in a catalytic converter. Write equations for any reactions you discuss. (11) (b) Petrol is obtained, not only by fractional distillation of crude oil, but also by cracking of hydrocarbons from heavy fractions. State why hydrocarbons from heavy fractions are cracked and explain why these hydrocarbons are less easy to ignite than those in petrol. (4) (Total 15 marks) 9. Ethene and other important hydrocarbons can be produced industrially from decane, C10H22. Name the process involved and give the name of the mechanism occurring. Write two equations for reactions in which ethene is formed from decane by this process. Explain the economic importance of the process. (Total 8 marks) 10. There are four structural isomers of molecular formula C4H9Br. The structural formulae of two of these isomers are given below. CH3CH2CH2CH2Br Isomer 1 Isomer 2 (ii) Name isomer 1. (Total 3 marks) 11. Catalytic cracking and thermal
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