OCR A Jun 2015 Paper 2 Q5

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5 Allyl bromide, CH2=CHCH2Br, is used in the production of polymers. 12 (a) Part of the C=C double bond in allyl bromide is called a -bond. Draw a labelled diagram to show the formation of the -bond. [2] (b) Allyl bromide is a member of a homologous series. Compounds in this series have the same general formula. (i) What is meant by the term homologous series?[2] (ii) What is the general formula of the homologous series that has allyl bromide as a member?[1] (iii) Give the systematic name for allyl bromide.[1] (c) Reaction mechanisms use curly arrows and can involve electrophiles and nucleophiles. (i) What does a curly arrow represent in mechanisms?[1] (ii) What is meant by the term nucleophile?[1]OCR 2015<br /> 13 (d) Allyl bromide, CH2=CHCH2Br, reacts with aqueous sodium hydroxide. (i) Outline the mechanism of this reaction. Include curly arrows, relevant dipoles and final product(s). [3] (ii) Name the type of mechanism.[1] (e) Allyl bromide, CH2=CHCH2Br, reacts with bromine, Br2. (i) Outline the mechanism of this reaction. Include curly arrows, relevant dipoles and the structures of the intermediate and final product(s). (ii) Name the type of mechanism.[1] [4]OCR 2015 Turn over<br /> (f) Allyl bromide is reacted as shown below. 14 CH2=CHCH2Br step 1 CH3CH2CH2Br 1-bromopropane step 2 Cl2 (i) State the reagents and conditions for step 1. mixture of organic products[1] (ii) In step 2, 1-bromopropane reacts with chlorine by radical substitution. Outline the mechanism for the monochlorination of 1-bromopropane. In your mechanism, you can show the formula of 1-bromopropane as C3H7Br. Include the names of the three stages in this mechanism, state the essential conditions and all termination steps.[5] (iii) Radical substitution produces a mixture of organic products. Suggest two reasons why.[2] [Total: 25]OCR 2015<br />

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