Edexcel Jun 2016 (IAL) Paper 1 Q

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20 Propene is an alkene which can be produced by cracking some of the hydrocarbons in crude oil. (a) Draw a dot and cross diagram showing the bonding in propene. Show outer electrons only. (b) (i) Propene is one product of the cracking of decane, C10H22. Write the equation for the reaction in which one mole of decane is cracked to produce one mole of ethene, one mole of propene and one other product. State symbols are not required. (ii) A synthetic rubber can be made by polymerizing a mixture of ethene and propene. Draw the structural formula of the repeat unit of this polymer which forms from one molecule of each alkene. (c) Propene is also used to make propane-1,2-diol. Give the reagents and colour change when this product is made at room temperature. (2) (1) (2) (3) ReagentsColour change fromtoA 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 A E R A S I H T N I E T I R W T O N O D *P46662A01720* 17 Turn over<br /> (d) The reaction of propene with bromine water is used as a test for the carbon-carbon double bond. State the colour change in this test. Draw the displayed formula of the organic product and give its name. (3) Colour change fromtoDisplayed formula of product Name(e) Write the mechanism for the reaction of propene with hydrogen bromide to give the major product. Include relevant dipoles. (4) 18 *P46662A01820* 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 D O N O T W R I T E I N T H I S A R E A<br /> *(f) Molecules of the element bromine, Br2, are not polar. Explain how bromine acts as an electrophile when it reacts with propene. (2)(g) In the United States of America, large deposits of shale gas have been discovered. This gas is trapped in rocks and can be extracted by fracking which involves breaking up the rock with water under pressure. Shale gas typically contains about 90% methane, mixed with about 3% ethane, 0.6% propane, 0.2% butane and 0.2% pentane. The rest is hydrogen, nitrogen and carbon dioxide. Suggest how the use of shale gas may affect the relative amounts of poly(ethene) and poly(propene) which are produced in the USA and justify your answer. (2)(Total for Question 20 = 19 marks) TOTAL FOR SECTION B = 60 MARKS TOTAL FOR PAPER = 80 MARKS 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 A E R A S I H T N I E T I R W T O N O D *P46662A01920* 19<br />

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