0620_s10_qp_31

UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONSInternational General Certificate of Secondary Education *3309238257* CHEMISTRY 0620/31 Paper 3 (Extended) May/June 2010 1 hour 15 minutes Candidates answer on the Question Paper. No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your Centre number, candidate number and name on all the work you hand in. Write in dark blue or black pen. You may use a pencil for any diagrams, graphs or rough working. Do not use staples, paper clips, highlighters, glue or correction fluid. DO NOT WRITE IN ANY BARCODES. Answer all questions. A copy of the Periodic Table is printed on page 16. For Examiner’s Use At the end of the examination, fasten all your work securely together. The number of marks is given in brackets [ ] at the end of each question or part question. 1 2 3 4 5 6 7 8 Total This document consists of 13 printed pages and 3 blank pages. IB10 06_0620_31/3RP © UCLES 2010 [Turn over www.XtremePapers.net ................................................................................................. forms a purple vapour... chloromethane (CH3Cl ) and an oxide of nitrogen (NO2)......................... ........................................................ Ozone is present in the upper atmosphere and it prevents dangerous solar radiation from reaching the Earth’s surface............................................................................................................................................................................... [1] [Total: 5] 2 Ozone is a form of oxygen.................................................. ............................................................. (i) It is a yellow solid which burns to form an acidic oxide... ..... .................. [3] (iii) How can chloromethane be made from methane? reagent ................ ...................................................................................................... condition ......................... ....................................................... ...........................................................XtremePapers............... [2] © UCLES 2010 0620/31/M/J/10 www. Name the compounds in the environment from which seaweed might have obtained the following elements: carbon....... ........................................................................................................................................ (i) Which of these three chemicals diffuses the most slowly? Give a reason for your choice...................................................................... chlorine................... ................................................. Some of the chemicals that diffuse into the upper atmosphere decompose ozone..... .2 1 For Examiner’s Use Choose an element which fits each of the following descriptions....................................... . [1] (ii) This element is a black solid which.......................................... [1] (iii) Most of its soluble salts are blue.................. [1] (v) It is an unreactive gas used to fill balloons......................................................................................... hydrogen.......................................................................................................................... [1] (iv) It has a basic oxide of the type MO which is used to treat acidic soils..................................... when heated................................................................................................................................... Chemicals that have this effect are methane (CH4)...............net .............................. [2] (ii) Chloromethane is formed when seaweed decomposes........................................ ....................................XtremePapers................ [2] [Total: 11] © UCLES 2010 0620/31/M/J/10 www..................................3 (iv) The oxides of nitrogen are atmospheric pollutants..................................................................... ....................................... ..............net [Turn over ....................................... ........................... Describe how they are formed......................................... For Examiner’s Use ........... O3 → .......... [2] (v) Complete the equation for the decomposition of ozone.......................................................................................... .....4 3 A diagram of the apparatus which could be used to investigate the rate of reaction between magnesium and an excess of an acid is drawn below....... (i) Suggest a reason why magnesium....... Why was copper a better choice than iron or zinc to weigh down the magnesium? ..... ................net For Examiner’s Use ......................................................................................0 mol / dm3 (excess) small piece of magnesium (a) The magnesium kept rising to the surface.. .............................. the magnesium was held down by a plastic net fastened to the beaker................ this was prevented by twisting the magnesium around a piece of copper.......................... [1] (ii) Iron.... floated to the surface............. zinc and copper have similar densities..................................................... [1] (b) The only difference in the two experiments was the method used to hold down the magnesium........................................ which is denser than water........................................ In a second experiment............ volume of hydrogen measured every 15 seconds hydrogen collects graduated tube 100 cm3 of acid 1........................... magnesium held down by copper volume of H2 / cm3 0 0 © UCLES 2010 magnesium held down by plastic time / s 0620/31/M/J/10 www............. The results are shown below....... In one experiment...... ...................................XtremePapers................................................................................... ............................................................................................ ..................net [Turn over .............................................5 (i) For Examiner’s Use In which experiment did the magnesium react faster? ................................................ [1] (d) Give two factors which would alter the rate of this reaction............XtremePapers........................ [1] (ii) How would the graph for propanoic acid be the same as the graph for hydrochloric acid? ... For each factor explain why it alters the rate.........................................................................................................0 mol / dm3 propanoic acid instead of 1............................................................................................................................................................................................ explanation ................. (i) How would the graph for propanoic acid differ from the graph for hydrochloric acid? ...................................................................... Propanoic acid is a weak acid..... [1] (c) The experiment was repeated using 1............................................................................................................................................................................ explanation .................................. factor ............................. [1] (ii) Suggest a reason why the experiment chosen in (i) had the faster rate............. factor ......................................................................................... [4] [Total: 10] © UCLES 2010 0620/31/M/J/10 www.. ................................................................................................................................................................................. ...........................................................................................................0 mol / dm3 hydrochloric acid................................ ............................. name ...................... O (a) Compounds containing the group C or COO are esters..................................................................................... ................................................. C17H35COOCH2 C17H35COOCH CH2OH + 3NaOH → 3C17H35COONa + CHOH C17H35COOCH2 CH2OH fat What type of compound has the formula C17H35COONa and what is its main use? type of compound .................................. [1] (iii) Name a synthetic polyester................ O (i) Give the names and formulae of the two compounds formed when the ester ethyl propanoate is hydrolysed........ [1] use ..........................................XtremePapers........ O CH3 CH2 C O CH2 CH3 name ............................ [1] © UCLES 2010 0620/31/M/J/10 www..........................................6 4 For Examiner’s Use Hydrolysis is used in chemistry to break down complex molecules into simpler ones...............net ...................... They can be hydrolysed by boiling with aqueous sodium hydroxide......................... formula formula [4] (ii) Fats are naturally occurring esters................................. ..................................... Both elements have macromolecular structures.............................................. .... [3] [Total: 14] 5 Carbon and silicon are elements in Group IV...................................... Describe how you could show that glycine was present on a chromatogram.............................................. [2] (ii) Give one use of diamond................................................... [3] (iii) A protein can be hydrolysed to a mixture of amino acids which are colourless................................................... (i) N C N C N C N C H O H O H O H O What is the name of the polymer linkage? ........... (i) Explain why diamond is a very hard substance...............................5............................ ................................................ [1] © UCLES 2010 0620/31/M/J/10 www...............................net [Turn over .......................7 For Examiner’s Use (b) The structure of a typical protein is drawn below.......... ......................................................................................................................................................... The Rf value of the amino acid glycine is 0............ (a) Diamond and graphite are two forms of the element carbon............ ............................................................... [1] (ii) Draw the structural formula of a man-made polymer with the same linkage............................................................................. .................................................................................................................... .........XtremePapers...................... .................................................................................................... Individual amino acids can be identified by chromatography............................ Use o to represent an electron from an oxygen atom...................................................... and silicon(IV) oxide................................................................................................................................................................. [1] (b) Two of the oxides of these elements are carbon dioxide......................................... [3] (ii) A section of the macromolecular structure of silicon(IV) oxide is given below......................XtremePapers........net .............................................. [2] (iii) Predict two differences in the physical properties of these two oxides........................ CO2................................. ......................................................................... [2] (iv) Give one use of graphite........... .......................................8 (iii) For Examiner’s Use Explain why graphite is a soft material............................................................................ ...................................................... [2] [Total: 13] © UCLES 2010 0620/31/M/J/10 www...................................... ....................................... ............................. (i) Draw a diagram showing the arrangement of the valency electrons in one molecule of the covalent compound carbon dioxide............................... ...... Use x to represent an electron from a carbon atom.... ........... SiO2.................................................. O Si O O O Use this diagram to explain why the formula is SiO2 not SiO4................................................................ ..................................................................... [1] (ii) Describe what you would observe..................................................................................... There is an equilibrium between these iodine chlorides............................................... ICl (l) + Cl2(g) dark brown ICl 3(s) yellow (a) Explain what is meant by equilibrium............ [2] (b) When the equilibrium mixture is heated it becomes a darker brown colour..................................net [Turn over .............. .................................................................................... .................................................................................................................................................................................................................................................................................................................................................................................................. ... .. I2 + Cl2 → 2ICl This reacts with more chlorine to give yellow iodine trichloride..........................9 6 For Examiner’s Use Iodine reacts with chlorine to form dark brown iodine monochloride................................. ................................. (i) How would this affect the position of equilibrium and why? It would move to the ........................ [1] reason ................................................................................................................................................................................................................... ................ [2] (c) The pressure on the equilibrium mixture is decreased................ [1] [Total: 7] © UCLES 2010 0620/31/M/J/10 www....................................................................................................................... ............................................................................ Is the reverse reaction endothermic or exothermic? Give a reason for your choice.............. ..... .......................................................................................................................XtremePapers.. ........................................ It is isolated by the following reactions.................................................... .....................................net .............. property related use soluble in molten steel making steel titanium alloys ....... [1] (b) Titanium(IV) chloride is made by heating the oxide with coke and chlorine.......... [2] © UCLES 2010 0620/31/M/J/10 www..................................................... [2] (c) Explain why the change.......................... ...................................................................................................................... titanium ore → titanium(IV) oxide → titanium(IV) chloride → titanium TiO2 TiCl 4 Ti (a) Why is it usually necessary to include a number in the name of the compounds of transition elements? . ......... TiO2 + 2Cl 2 2C + O2 TiCl 4 + O2 2CO Explain why the presence of coke ensures the maximum yield of the metal chloride......................................................... making aircraft and space vehicles resistant to corrosion.............................................................................................................. ...................................................................................................................... is reduction...........................................................................................................10 7 For Examiner’s Use Titanium is a transition element...............................XtremePapers......................................................................................... [1] (d) Complete the table which shows some of the properties of titanium and its uses................. The first line has been completed as an example.... .................... especially in sea water .. titanium(IV) chloride to titanium.......................................... .....................................................6% titanium and the remainder is oxygen........8 / 56 = 0.................................net [Turn over ......................................... (i) Determine the percentage of oxygen in this titanium compound......................... : Ti : ...... 31.......... [1] (iv) What is the formula of this titanium compound? .. The number of moles of Fe is shown as an example..11 For Examiner’s Use (e) The titanium ore contains 36....... % (ii) [1] Calculate the number of moles of atoms for each element.................................................................................66 number of moles of Ti = .................................................8% iron......................XtremePapers........ [1] (iii) What is the simplest ratio for the moles of atoms? Fe ............................... [1] [Total: 10] © UCLES 2010 0620/31/M/J/10 www..... percentage of oxygen = .......... O ....... number of moles of Fe = 36.......................... number of moles of O = .. ...................................................... HCOOH + CaCO3 → Ca(HCOO)2 + ............................... ............................................................................................... [2] (ii) Methanoic acid reacts with most metals above hydrogen in the reactivity series......................................................................................... [1] [Total: 10] © UCLES 2010 0620/31/M/J/10 www.............................XtremePapers.............. (i) Complete the equation...... [1] empirical formula ........................................ [1] molecular formula . [1] (c) Give the name.................................. name ........................................................12 8 For Examiner’s Use Methanoic acid is the first member of the homologous series of carboxylic acids................................................................................ [2] (b) In some areas when water is boiled. (a) Give two general characteristics of a homologous series.................................................... ........ Complete the word equation............................ ............... Why does methanoic acid not react with an aluminium kettle? .. zinc + methanoic acid → ......... This can be removed by adding methanoic acid............ ............................................................................................. [2] (iii) Aluminium is also above hydrogen in the reactivity series.............................................................................................. + .. molecular formula and empirical formula of the fourth acid in this series.........................................................................................................................................................................net ................ + ................... the inside of kettles become coated with a layer of calcium carbonate................................................................................ .................. 13 BLANK PAGE © UCLES 2010 0620/31/M/J/10 www.XtremePapers.net . net .14 BLANK PAGE © UCLES 2010 0620/31/M/J/10 www.XtremePapers. net .XtremePapers.15 BLANK PAGE © UCLES 2010 0620/31/M/J/10 www. net Key b X a 72 b = proton (atomic) number X = atomic symbol a = relative atomic mass *58-71 Lanthanoid series 90-103 Actinoid series 88 Ac Actinium Ra Radium Fr Francium 87 * Hafnium Lanthanum 57 178 Hf 40 Zirconium Zr 91 Titanium 139 Yttrium 22 48 Ti La 39 Y 89 Scandium 21 227 56 Barium Caesium 45 Sc 226 55 137 Ba 133 Cs 38 Rubidium 37 88 Sr 85 Rb 20 Potassium 19 40 Ca 39 12 24 Mg 23 Na Beryllium 4 Lithium K 11 3 9 Be 7 II Li I 93 Ta 181 Niobium Nb 90 58 73 52 96 Mo W 184 Protactinium Thorium 55 Tc 186 Re 144 Nd 92 60 Uranium U 238 Neodymium 75 Rhenium 43 Technetium 25 Manganese Mn 27 59 28 59 29 64 30 65 5 Ru 101 Iron 190 Pm Osmium Os 93 Np Neptunium 61 Promethium 76 44 Ruthenium 26 56 Fe Sm 150 Iridium 94 Pu Plutonium 62 152 Eu 95 Am Americium 63 Europium 78 Platinum 195 Pt 192 46 Palladium Pd 106 Nickel Ni Ir Samarium 77 45 Rhodium Rh 103 Cobalt Co Gd 157 Gold Au 197 Silver 96 64 Curium Cm Gadolinium 79 47 Ag 108 Copper Cu 201 Bk Terbium Tb 159 Mercury Hg 97 Berkelium 65 80 48 Cadmium Cd 112 Zinc Zn 11 6 Dy 162 Thallium Tl 204 Indium 98 Cf Californium 66 Es Holmium Ho 165 Lead Pb 207 Tin 99 Einsteinium 67 82 50 119 Sn 115 32 Germanium Ge 73 Silicon In Gallium Dysprosium 81 49 31 70 Ga 14 28 Si Carbon 27 Aluminium 13 12 C Al Boron B 7 14 75 Sb 122 Arsenic As Bi 209 Fermium Fm Erbium Er 167 Bismuth 100 68 83 51 Antimony 33 15 Phosphorus P 31 Nitrogen N 8 Se 79 Sulfur S 32 Oxygen Po 169 Md Thulium Tm 101 Mendelevium 69 84 Polonium 52 Tellurium Te 128 Selenium 34 16 16 O 9 Yb 173 Astatine At Iodine I 127 Bromine Br 80 Chlorine No 102 Nobelium 70 Ytterbium 85 53 35 17 Cl 35.© UCLES 2010 Magnesium Sodium Calcium Strontium 89 0620/31/M/J/10 www. Cambridge Assessment is the brand name of University of Cambridge Local Examinations Syndicate (UCLES). University of Cambridge International Examinations is part of the Cambridge Assessment Group.XtremePapers. Every reasonable effort has been made by the publisher (UCLES) to trace copyright holders.5 Fluorine F 19 Lr Lutetium Lu 175 Radon Rn Xenon Xe 131 Krypton Kr 84 Argon Ar 40 Neon 103 Lawrencium 71 86 54 36 18 10 Ne 20 Helium 2 0 Hydrogen VII 4 VI He V 1 IV H III The volume of one mole of any gas is 24 dm3 at room temperature and pressure (r.t.p. but if any items requiring clearance have unwittingly been included the publisher will be pleased to make amends at the earliest possible opportunity. . 91 Pa Th 232 Praseodymium Cerium 59 141 Pr 140 74 Tungsten 42 Molybdenum 24 Chromium Cr Ce Tantalum 41 23 Vanadium V 51 1 Group DATA SHEET The Periodic Table of the Elements 16 Permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible.). which is itself a department of the University of Cambridge.