Edexcel Jan 2013 Paper 3 Q2

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2 Consider the following reaction scheme. Colourless liquid S C3H8O PCl5 Colourless organic liquid X K2Cr2O7 in acidic solution, heat under reflux liquid T Organic gas Q KOH in ethanol, heat AgNO3 in aqueous ethanol warm White precipitate R The infrared spectrum of compound S is shown below. Transmittance / % 100 50 0 4000 3000 2000 1500 1000 Wavenumber / cm1 *P41216A0616*<br /> Bond C H O H C C C O Group alkane alkene alcohol alkene aldehyde ketone Wavenumber range / cm1 29622853 30953010 37503200 16691645 1740 1720 17201680 (a) (i) Give the wavenumber range of the absorption in the infrared spectrum that shows that compound S is an alcohol. (1)(ii) Identify the type of organic compound formed in the reaction of S with phosphorus(V) chloride, PCl5. (1)*P41216A0716* Turn over<br /> (b) Compound T does not produce carbon dioxide when added to a solution of sodium carbonate. From this information alone, what can you deduce about compound T? (1)(c) The infrared spectrum of liquid T is shown below. Transmittance / % 100 50 0 4000 3000 2000 1500 Wavenumber / cm1 1000 500 (i) Give the wavenumber range of the absorption in the infrared spectrum that shows that compound T is formed from a secondary alcohol. (1)(ii) Identify the type of organic compound T. (1)*P41216A0816*<br /> (iii) Draw the skeletal formula for S. (d) Liquid X gives a white precipitate, R, on warming with an aqueous ethanolic solution of silver nitrate. (i) Identify R by name or formula. (1) (1)(ii) Describe what you would see if precipitate R was left in sunlight. (1)(iii) Suggest why an aqueous ethanolic solution of silver nitrate gives a better result in this test than would be obtained by aqueous silver nitrate. (1)*P41216A0916* Turn over<br /> (e) If X is heated with a concentrated ethanolic solution of potassium hydroxide, a gas Q is produced. (i) Describe a test and its expected result to show that this gas is an alkene. (2) TestResult(ii) Give the displayed formula of the alkene Q. (1) (Total for Question 2 = 12 marks) 10 *P41216A01016*<br />

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