OCR A Specimen Paper 2 Q19

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24 (a) The flowchart below shows some reactions of an AHA, CH3(CH2)2CHOHCOOH. 19 -Hydroxy acids (AHAs) are naturally occurring acids often used as cosmetics. (i) Fill in the boxes to show the organic products of Reactions 1 and 2, clearly showing the relevant functional groups. Reaction 1 Reaction 2 heat CH3COOH and H2SO4 CH3(CH2)2CHOHCOOH Specimen NaBr and H2SO4 heat H3PO4 heat Reaction 3 (ii) Give the full systematic name for compound G. H3CH2C Compound G Compound H [2][1]OCR 2014 H432/02<br /> (iii) Compound H is a stereoisomer of compound G. 25Suggest a structure for compound H.Draw the repeat unit of the addition polymer that can be formed from compound H. Compound H addition polymer (iv) The addition polymer in (iii) is used widely in industry. Increasingly, waste polymers are being processed as a more sustainable option than disposal. Apart from recycling, state two methods for usefully processing waste polymers. .Specimen [2] [2]OCR 2014 H432/02 Turn over<br /> (b) A student synthesises a sample of the AHA J using the following reaction scheme, starting from propane-1,2-diol. 26 propane-1,2-diol [O] Step 1 (i) In the space below: NaBH4 Step 2 Compound J state a suitable oxidising agent for Step 1write an equation for Step 1outline the mechanism for Step 2, showing curly arrows and relevant dipoles. Specimen.OCR 2014 H432/02 [5]<br /> 27 (ii) The reagent used in Step 2 of the synthesis in (i) was NaBH4. NaBH4 contains the ions Na+ and [BH4]. Draw a dot-and-cross diagram of NaBH4 and give the full electron configuration of Na+. Show outer shells of electrons only. full electronic configuration of Na+:[2] SpecimenOCR 2014 H432/02 Turn over<br /> 28 (c) Compound K is an AHA that is often used in chemical face peels. A student wishes to identify compound K from the list of compounds below. glycolic acid malic acid mandelic acid pantoic acid HOCH2COOH HOOCCH2CHOHCOOH C6H5CHOHCOOH HOCH2C(CH3)2CHOHCOOH The student isolates compound K and analyses a sample of the compound by titration. The student dissolves 1.89 g of compound K in water and makes the solution up to 250.0 cm3 in a volumetric flask. The student titrates 25.0 cm3 of this solution with 0.150 mol dm3 NaOH(aq). 18.80 cm3 of NaOH(aq) were required for complete neutralisation. Use the results of the students analysis to identify compound K from the list above. Show all of your working. Specimen K =[5]OCR 2014 H432/02<br /> 29 BLANK PAGE SpecimenOCR 2014 H432/02 Turn over<br />

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