OCR A Jun 2016 Paper 2 Q2

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This question is about the homologous series of alcohols. (a) What is meant by the term homologous series?[2] (b) Ethanol is used more than any other alcohol. One method of preparing ethanol uses yeast. Write the equation for this preparation and state the essential conditions.[2] (c) At room temperature and pressure, the first four members of the alkanes are all gases but the first four alcohols are all liquids. Explain this difference in terms of intermolecular forces.[2] (d) The boiling points of 2-methylpropan-1-ol and butan-1-ol are shown below. Alcohol Boiling point / C 2-methylpropan-1-ol butan-1-ol 108 117 Explain why the boiling points are different.[2]OCR 2016<br />
 (e) Alkenes can be prepared from alcohols. Cyclopentene can be prepared from cyclopentanol as shown in the equation below. OH A student plans to prepare 5.00 g of cyclopentene from cyclopentanol. The percentage yield of this reaction is 45.0%. (i) What is the name of this type of reaction?[1] (ii) Calculate the mass of cyclopentanol that the student should use. Show your working. mass of cyclopentanol =g [3]OCR 2016 Turn over<br />
 (f) Alcohols can be prepared from halogenoalkanes. 2,2-dimethylpropan-1-ol can be prepared by hydrolysis of a chloroalkane with aqueous sodium hydroxide. (i) Write the equation for this reaction. Use structures for the organic compounds. (ii) Outline the mechanism for this reaction. Show curly arrows and relevant dipoles.OCR 2016 [1] [2] [Total: 15]<br />

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