Edexcel Jun 2016 Paper 5 Q21

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21 (a) The structures of 2-aminopropanoic acid and 3-aminopropanoic acid are shown. H C C C NH2 OH H2N C C C OH 2-aminopropanoic acid 3-aminopropanoic acid (i) Explain how the low resolution proton nmr spectra of these two amino acids differ. (2)(ii) Explain whether or not 3-aminopropanoic acid is chiral. (1)(iii) Write ionic equations for the reaction of 3-aminopropanoic acid with (2) H+ ions OH ions A E R A S I H T N I E T I R W T O N O D A E R A S I H T N I E T I R W T O N O D A E R A S I H T N I E T I R W T O N O D *P46661A01732* 17 Turn over<br /> (iv) Draw two repeat units of the polymer formed when 3-aminopropanoic acid polymerizes. (1) (b) The food colouring E110 is also known as Sunset Yellow. It can be synthesised as shown below. NH2 Step 1 N+ N Cl NaO3S Step 2 NaO3S HO NaO3S Sunset Yellow SO3Na (i) Give the reagents and condition for Step 1. (2)18 *P46661A01832* D O N O T W R I T E I N T H I S A R E A D O N O T W R I T E I N T H I S A R E A D O N O T W R I T E I N T H I S A R E A<br /> (ii) Draw the structure of the reagent needed for Step 2. (iii) Explain why Sunset Yellow can exist as geometric isomers. (1) (1)*(iv) Describe the essential steps of the method that you would use to prepare a pure, dry sample of the solid Sunset Yellow from an impure sample of the food colouring. You may assume that ethanol is a suitable solvent for this method. (4)A E R A S I H T N I E T I R W T O N O D A E R A S I H T N I E T I R W T O N O D A E R A S I H T N I E T I R W T O N O D*P46661A01932* 19 Turn over<br /> (v) Suggest how you could check that a sample of Sunset Yellow is pure. (1)(c) Explain how a chemist could use phenylmethanol to synthesise a sample of benzamide in three steps. CH2OH NH2 phenylmethanol benzamide Include the reagents for the steps in the synthesis and draw the structures of all the intermediates. (5) (Total for Question 21 = 20 marks) 20 *P46661A02032* D O N O T W R I T E I N T H I S A R E A D O N O T W R I T E I N T H I S A R E A D O N O T W R I T E I N T H I S A R E A<br />

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