Edexcel Jan 2016 (IAL) Paper 4 Q21

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21 An organic compound, X, has the molecular formula C6H12O2 and contains one functional group. (a) The infrared spectrum of X is shown below. Relative transmittance 0.9 0.8 0.7 0.6 4000 3000 2000 Wavenumber / cm1 D O N O T W R I T E I N T H I S A R E A 1000 Identify the bonds responsible for the peaks labelled Q and R in the spectrum by referring to your Data Booklet. Hence deduce the functional group present in X. (2) QRFunctional Group24 *P46940A02428* 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 /> 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 (b) When X is heated under reflux with dilute sulfuric acid, two organic products, Y and Z, are formed. The mass spectrum of Y is shown below. Relative intensity 100 80 60 40 20 0.0 0.0 10 20 30 40 50 60 70 m/e (i) Y reacts with sodium carbonate solution producing carbon dioxide. Use this information, together with the mass spectrum, to identify Y. Explain your reasoning. (3)A E R A S I H T N I E T I R W T O N O D *P46940A02528* 25 Turn over<br /> (ii) Z has molecular formula C4H10O. Z reacts with sodium, producing a gas. When Z is warmed with a mixture of potassium dichromate(VI) and sulfuric acid, no reaction occurs. Deduce the structural formula of Z. Explain your reasoning and give the equation for the reaction with sodium producing a gas. (3)D O N O T W R I T E I N T H I S A R E AEquation for reaction of Z with sodium: (iii) Use your answers to part (a), part (b)(i) and (b)(ii) to deduce the displayed formula of X. (1) 26 *P46940A02628* 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 /> (iv) Evidence for the structure of X comes from its proton nmr spectra. Use the formula you have deduced in (b)(iii) to predict the number of peaks and their relative areas in the low resolution nmr spectrum of X. State the splitting pattern of each peak in the high resolution nmr spectrum. Justify your answers. (3) A E R A S I H T N I E T I R W T O N O DA 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(Total for Question 21 = 12 marks) TOTAL FOR SECTION C = 19 MARKS TOTAL FOR PAPER = 90 MARKS I E T I R W T O N O D *P46940A02728* 27<br />

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