CIE Jun 2014 v3 Paper 2 Q1

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Answer all the questions in the spaces provided. (a) De ne the term mole. PMT[1] (b) 10 cm3 of a gaseous hydrocarbon, CxHy, was reacted with 100 cm3 of oxygen gas, an excess. Thenal volume of the gaseous mixture was 95 cm3. This gaseous mixture was treated with concentrated, aqueous sodium hydroxide to absorb the carbon dioxide present. This reduced the gas volume to 75 cm3. All gas volumes were measured at 298 K and 100 kPa. (i) Write an equation for the reaction between sodium hydroxide and carbon dioxide.[1] (ii) Calculate the volume of carbon dioxide produced by the combustion of the hydrocarbon. (iii) Calculate the volume of oxygen used up in the reaction with the hydrocarbon. volume of CO2 produced =cm3 [1] (iv) Use your answers to (b)(ii) and (b)(iii), together with the initial volume of hydrocarbon, to balance the equation below. volume of O2 used =cm3 [1] CxHy + O2CO2 + zH2O (v) Deduce the values of x, y and z in the equation in (iv). x =y =z =[2] [3]UCLES 2014 9701/23/M/J/14<br /> PMT (c) Another hydrocarbon, W, with the formula C4H8, reacts with hydrogen bromide, HBr, to give two products X and Y. X and Y are structural isomers of molecular formula C4H9Br. Reaction of X with aqueous alkali produces an alcohol, Z, that has no reaction with acidi ed dichromate(VI). (i) Give the structures and names of the compounds W, X, Y, and Z[4] (ii) When W reacts with hydrogen bromide, more X than Y is produced. Explain why.[2] [Total: 15]UCLES 2014 9701/23/M/J/14 [Turn over<br />

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