CIE Jun 2015 v1 Paper 4 Q6

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10 1,3-dimethylbenzene is a useful starting material for several commercially important compounds. (a) The arti cial musk ketone, A, is a perfume agent added to many cosmetics and detergents. It is made from 1,3-dimethylbenzene by the following route. step 1 step 2 step 3 1,3-dimethylbenzene O2N NO2 musk ketone A (i) The only by-product of step 2 is HCl. Suggest the reagent that was used in this step.[1] (ii) Suggest the type of reaction that is occurring during both step 2 and step 3.[1] (iii) State the reagents and conditions needed for step 3.[1] (iv) Suggest the structures of the two products formed when A is reacted with alkaline aqueous iodine. [2]UCLES 2015 9701/41/M/J/15<br /> 11 (b) 1,3-dimethylbenzene is also a starting material for the synthesis of the polymer Nomex, used inreproof protective clothing worn byre ghters, military pilots and racing car drivers. The polymer is made from 1,3-dimethylbenzene and 1,3-dinitrobenzene by the following route. HO2C step 1 CO2H step 2 1,3-dimethylbenzene H2N NH2 O2N NO2 1,3-dinitrobenzene step 3 Nomex (i) Draw the structure of one repeat unit of Nomex in the box above. [1] (ii) What type of polymer is Nomex?[1] (iii) Suggest the by-product formed during step 3.[1] (iv) Suggest reagents and conditions for step 2.[1] (v) Suggest how and why the properties of the polymer might change if some of the diamine monomer were replaced with 1,3,5-triaminobenzene. H2N NH2 NH2 1,3,5-triaminobenzene[1]UCLES 2015 9701/41/M/J/15 [Total: 10] [Turn over<br />

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