OCR_A level Chemistry_Paper 2_2020 | SPS F108 12.2_Carbonyl Compounds, Carboxylic Acids, Esters & Polyesters | QUESTIONS ONLY

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SPS F108 12.2_Carbonyl Compounds, Carboxylic Acids, Esters & Polyesters_A level_OCR_Chemistry_Paper 2 Carbonyl Compounds, Carboxylic Acids, Esters & Polyesters Question Paper 2 Level A Level ... Exam Board OCR Sub-Topic Time Allowed: 76 minutes Score: /63 Percentage: /100 Grade Boundaries: A* A B C D E U >85% 77.5% 70% 62.5% 57.5% 45% <45% 1 Mandelic acid (2-phenyl-2-hydroxyethanoic acid), C6H5CH(OH)COOH, is used in some skin creams and can be converted into a condensation polymer. The addition polymer of ethyl methacrylate (ethyl 2-methyl-2-propenoate), CH2C(CH3)COOC2H5, is used to make some artificial fingernails. (a) Explain what is meant by the term condensation polymerisation. Your answer should use appropriate technical terms, spelled correctly. ................................................................................................................................................... ................................................................................................................................................... .............................................................................................................................................. [1] (b) Draw two repeat units of a polymer that is formed when, (i) mandelic acid, C6H5CH(OH)COOH, polymerises (ii) ethyl methacrylate, CH2C(CH3)COOC2H5, polymerises. [2] [1] (c) When ethyl methacrylate, CH2C(CH3)COOC2H5, is heated under reflux with aqueous dilute acid, a hydrolysis reaction takes place forming compound C and ethanol. When compound C is heated with steam in the presence of an acid catalyst, an addition reaction takes place forming two organic products D and E. Compounds D and E are structural isomers with the molecular formula C4H8O3. Draw the structures of compounds C, D and E. [3] TURN OVER FOR PART (d) (d) Mandelic acid has anti-bacterial properties and is used in some skin creams. A cosmetic chemist used mandelic acid to prepare two different esters that might be suitable for new skin creams. The structures of the two esters are shown below. O HO ester 1 O ester 2 (i) Draw the structure of an organic compound that could react with mandelic acid, C6H5CH(OH)COOH, to produce ester 1. [1] (ii) Identify an organic compound that could react with mandelic acid to produce ester 2. [1] (iii) Ester 1 is less soluble in water than mandelic acid, C6H5CH(OH)COOH. Explain the difference in water solubility of mandelic acid and ester 1. You may use a labelled diagram in your answer. [Show More]

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