OCR A Jun 2016 Paper 2 Q7

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7 A student was provided with a mixture of two structural isomers. Each isomer has the percentage composition by mass C, 29.29%; H, 5.70%; Br, 65.01%. The relative molecular mass of each isomer is less than 150. 21 (a) Determine the structures of the two structural isomers. Show your working. In your answer you should link the evidence with your explanation.[5]OCR 2016 Turn over<br />
 22 (b) The student heats the mixture of the two structural isomers from (a) under reflux with aqueous sodium hydroxide to form two compounds, E and F. The student separates the two compounds. Compound E is heated under reflux with acidified potassium dichromate(VI) to form compound G, which gives the infrared spectrum below. 100 transmittance (%) 50 0 4000 3000 2000 1500 wavenumber / cm1 1000 500 (i) Analyse the information and spectrum to determine the structures of E, F and G. Include an equation for the formation of G from E. In your answer you should link the evidence with your explanation.OCR 2016<br />
 23[6] (ii) Compound G is heated with compound F in the presence of a small amount of concentrated sulfuric acid to form organic compound H. Draw the structure of the organic compound H. END OF QUESTION PAPER [2] [Total: 13]OCR 2016<br />

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