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CIE Jun 2013 v2 Paper 4 Q5
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![Examiners For Use Coffee beans contain chlorogenic acid. O OH OH HO HO chlorogenic acid OH OH (a) (i) Draw circles around any chiral centres in the above structure. (ii) Write down the molecular formula of chlorogenic acid.(iii) How many moles of H2(g) will be evolved when 1 mol of chlorogenic acid reacts with an excess of sodium metal?(iv) How many moles of NaOH(aq) will react with 1 mol of chlorogenic acid under each of the following conditions? in the coldon heating[6]UCLES 2013 9701/42/M/J/13 [Turn over<br />
Examiners For Use (b) On heating with dilute aqueous acid, chlorogenic acid produces two compounds, D and E. 10 chlorogenic acid dil. H+(aq) heat HO conc. H2SO4 heat OH HO OH OH HO OH OH Br2(aq) in excess C7H6O3 (i) What type of reaction is chlorogenic acid undergoing when D and E are formed?When compound D is heated with concentrated H2SO4, compound F, C7H6O3, is formed. Compound F evolves CO2(g) when treated with Na2CO3(aq), and decolourises Br2(aq), giving a white precipitate. It does not, however, decolourise cold dilute acidi ed KMnO4. When compound E is treated with an excess of Br2(aq), compound G is produced. (ii) If the test with cold dilute acidi ed KMnO4 had been positive, which functional group would this have shown to be present in F?(iii) Name the functional groups in compound F that would react with the following. Na2CO3(aq)Br2(aq)(iv) Suggest structures for compounds F and G and draw them in the relevant boxes above.UCLES 2013 9701/42/M/J/13<br />
Examiners For Use 11 (v) Compound E is one of a pair of stereoisomers. What type of stereoisomerism is shown by compound E?(vi) Draw the structure of the other stereoisomer in the box below. (c) Calculate the volume of 0.1 mol dm3 NaOH that is needed to react completely with 0.1 g of compound E. [8] volume =cm3 [3] [Total: 17]UCLES 2013 9701/42/M/J/13 [Turn over<br />
12 BLANK PAGEUCLES 2013 9701/42/M/J/13<br />](https://learnah.org/wp-content/uploads/2018/08/June_2013_v2_QP_-_Paper_4_CIE_Chemistry_A-level_5-0.jpg)
![Page 8 (a) (i) Mark Scheme GCE A LEVELMay/June 2013 Syllabus 9701 Paper 42 OH OH two or three centres correctly identified [1] four centres correctly identified [2] [1] [1] [1] [1] [6] [1] [1] [1] [1] OH OH HO HO (ii) C16H18O9 (iii) 3 moles of H2 (iv) in cold: 3 moles of NaOH on heating: 4 moles of NaOH (b) (i) hydrolysis (ii) alkene or C=C (iii) with Na2CO3(aq): carboxylic acid with Br2(aq): phenol (iv) Br(OH) Br OH Br (OH) CO2H OH OH Br HO2C (OH can be at the 3, 4, or 5 positions, but not the 2 or 6 positions) [1] (v) geometrical or cis-trans or E-Z G (ring subst. allow 2 or 3 Br in ring) [1] (addition to C=C: allow one of the aliphatic Br to be OH, but not both) [1] [1]Cambridge International Examinations 2013<br />
Page 9 Mark Scheme GCE A LEVELMay/June 2013 Syllabus 9701 Paper 42 (vi) HO2C OH OH (c) Mr(E) = 180, so 0.1 g = 1/1800 (5.56 x 10-4) mol skeletal or structural [1] [9 max 8] [1] [1] [1] [3] 3 mol NaOH react with 1 mol of E, so n(NaOH) = 3/1800 = 1/600 mol = 1.6710-3 mol volume of 0.1M NaOH = 1000/(600 x 0.1) = 16.7 cm3 [Total: 17]Cambridge International Examinations 2013<br />](https://learnah.org/wp-content/uploads/2018/08/June_2013_v2_MS_-_Paper_4_CIE_Chemistry_A-level_5-0.jpg)
