Chemistry Past Exam Paper (Cambridge Igcse)

UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS International General Certi? cate of Secondary Education *4308315385* CHEMISTRY Paper 2 Candidates answer on the Question Paper. No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your Centre number, candidate number and name in the spaces at the top of this page. Write in dark blue or black pen. You may need to use a pencil for any diagrams, graphs or rough working. Do not use staples, paper clips, highlighters, glue or correction ? uid. DO NOT WRITE IN ANY BARCODES. Answer all questions.

A copy of the Periodic Table is printed on page 20. 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. 0620/21 October/November 2010 1 hour 15 minutes For Examiner’s Use 1 2 3 4 5 6 7 8 Total This document consists of 17 printed pages and 3 blank pages. IB10 11_0620_21/4RP © UCLES 2010 [Turn over 2 1 The diagram below shows the elements in a period of the Periodic Table. For Examiner’s Use Li Be B C N O F Ne (a) To which period of the Periodic Table do these elements belong? …………………………………………………………………………………………………………………… [1] (b) Answer these questions using only the elements shown in the diagram. Each element can be used once, more than once or not at all. Write down the symbol for the element which (i) has six electrons in its outer shell. (ii) is a halogen. (iii) is a metal which reacts rapidly with cold water. (iv) has two forms, graphite and diamond. (v) is in Group II of the Periodic Table. (vi) makes up about 80 % of the air. ………………………………… ……………………………….. ………………………………… ………………………………… ………………………………… …………………………… [6] (c) Complete the following sentence using words from the list below. atoms electrons molecules neutrons protons The ………………………….. of the elements in the Periodic Table are arranged in order of increasing number of ………………………….. . [2] [Total: 9] © UCLES 2010 0620/21/O/N/10 3 2 Calcium carbonate was heated strongly in a test-tube. The gas given off was bubbled through limewater.

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For Examiner’s Use limewater calcium carbonate heat (a) What type of chemical reaction occurs when calcium carbonate is heated strongly? Put a ring around the correct answer. hydration neutralisation oxidation thermal decomposition [1] (b) (i) State the name of the gas given off when calcium carbonate is heated strongly. ……………………………………………………………………………………………………………… [1] (ii) State the colour change of the limewater. ……………………………………………………………………………………………………………… 1] (c) The product remaining in the test-tube is calcium oxide. (i) Calcium oxide is used in steelmaking. Describe how and why calcium oxide is used in making steel. …………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………… [2] (ii) Steel is an alloy.

What do you understand by the term alloy ? …………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………… [1] © UCLES 2010 0620/21/O/N/10 [Turn over 4 (iii) Give one other use of calcium oxide. ………………………………………………………………….. …………………………………………. [1] (iv) Complete the symbol equation for the reaction of calcium oxide with hydrochloric acid.

CaO + …………… HCl > CaCl 2 + …………… (v) State the chemical name of the compound CaCl 2. ……………………………………………………………………………………………………………… [1] [Total: 10] [2] For Examiner’s Use © UCLES 2010 0620/21/O/N/10 5 3 Helium and argon are noble gases. (a) State one use of helium. ……………………………………………………………………………………………………………………. [1] (b) The atomic structures of helium and argon are shown below. For Examiner’s Use X helium argon i) State the name of the central part of the atom, labelled X. ……………………………………………………………………………………………………………… [1] (ii) Which statement about helium and argon is correct? Tick one box. Argon has an incomplete inner shell of electrons. An atom of argon has 16 electrons. Helium has a complete outer shell of electrons. Helium has an incomplete outer shell of electrons. [1] (iii) How many protons are there in an atom of argon? ……………………………………………………………………………………………………………… 1] (iv) The symbol for a particular isotope of helium is written as 4 He . 2 Write a similar symbol for the isotope of argon which has 16 neutrons. [1] © UCLES 2010 0620/21/O/N/10 [Turn over 6 (c) Argon is a liquid at a temperature of –188 °C. Complete the diagram below to show how the atoms of argon are arranged at –188 °C. represents one atom of argon. For Examiner’s Use [2] [Total: 7] © UCLES 2010 0620/21/O/N/10 7 4 The table shows the mass of some ions present in a 500 cm3 bottle of mineral water. name of ion calcium symbol Ca2+ Cl – magnesium nitrate potassium Mg2+ NO3– K+ SO42– (a) State the name of the following ions.

Cl – …………………………………………………………………………………………………………………… SO42– …………………………………………………………………………………………………………… [2] (b) Calculate the mass of magnesium ions in 100 cm3 of this mineral water. mass of ion / mg 40. 5 8. 1 11. 6 2. 4 0. 9 6. 4 For Examiner’s Use [1] (c) (i) Describe a test for nitrate ions. …………………………………………………………………………………………………………………… …………………………………………………………………………………………………………….. [2] (ii) The gas produced in this test turns damp red litmus paper blue. State the name of this gas. ………………………………………………………………….. …………………………………………. [1] © UCLES 2010 0620/21/O/N/10 [Turn over 8 (d) The apparatus shown is used to get pure water from impure mineral water. For Examiner’s Use mineral water heat (i) Complete the diagram by putting the correct labels in the three boxes. ii) Describe how this apparatus separates pure water from dissolved ionic solids. [3] …………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………… [2] (iii) Water purity is important in everyday life. Describe one other area of everyday life where purity of substances is important. …………………………………………………………………………………………………………….. [1] [Total: 12] © UCLES 2010 0620/21/O/N/10 9 5 A solution of calcium hydroxide in water is alkaline. (a) Which one of the pH values below is alkaline? Put a ring around the correct answer. pH 3 pH 6 pH 7 pH 11 [1] For Examiner’s Use (b) Which of the following is the common name for calcium hydroxide? Tick one box. cement limestone quicklime slaked lime [1] (c) Some farmers use calcium hydroxide to control soil acidity. (i) Why is it important to control soil acidity? …………………………………………………………………………………………………………….. [1] (ii) Acid rain can cause soil to become acidic. Describe how acid rain is formed. …………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………… …………………………………………………………………………………………………………….. [3] (d) Calcium hydroxide reacts with hydrochloric acid. calcium hydroxide + hydrochloric acid > calcium chloride + water (i) State the name of this type of chemical reaction. ……………………………………………………………………………………………………………… [1] © UCLES 2010 0620/21/O/N/10 [Turn over 10 (ii) A dilute solution of calcium hydroxide can be titrated with hydrochloric acid using the apparatus shown. For Examiner’s Use burette hydrochloric acid lask solution of calcium hydroxide Describe how you would carry out this titration. …………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………… 3] [Total: 10] © UCLES 2010 0620/21/O/N/10 11 6 Iron is extracted from its ore by reduction with carbon. Aluminium is extracted from its ore by electrolysis. (a) (i) State the name of an ore of aluminium. ……………………………………………………………………………………………………………… [1] (ii) What do you understand by the term reduction ? ……………………………………………………………………………………………………………… [1] (iii) Suggest why aluminium is not extracted from its ore by reduction with carbon. …………………………………………………………………………………………………………….. [1] (b) The table gives information about the reduction of four different metal oxides by heating with carbon. metal oxide lead(II) oxide magnesium oxide nickel(II) oxide zinc oxide reduction conditions reduced very easily using a Bunsen burner reduced with dif? culty in a furnace above 2000 °C reduced very easily in a furnace above 680 °C reduced fairly easily in a furnace above 1200 °C For Examiner’s Use Use the information in the table to suggest the order of reactivity of these etals. least reactive most reactive [2] (c) Zinc powder reacts with hydrochloric acid. The speed of reaction can be followed by measuring the volume of hydrogen gas produced per minute. What happens to the volume of gas produced per minute when (i) large lumps of zinc are used instead of zinc powder? ……………………………………………………………………………………………………………… [1] (ii) the reaction is carried out at a higher temperature? ……………………………………………………………………………………………………………… 1] © UCLES 2010 0620/21/O/N/10 [Turn over 12 (d) Match the metals on the left with their uses on the right. The ? rst one has been done for you. For Examiner’s Use nickel electrical wiring copper making coins aluminium chemical plant mild steel car bodies stainless steel aircraft bodies [4] [Total: 11] © UCLES 2010 0620/21/O/N/10 13 7 Ethene, C2H4, is manufactured by cracking petroleum fractions. (a) (i) What do you understand by the term petroleum fraction ? …………………………………………………………………………………………………………………… …………………………………………………………………………………………………………….. [1] (ii) Complete the equation for the manufacture of ethene from dodecane, C12H26. C12H26 > C2H4 + …………… [1] For Examiner’s Use (b) Two fractions obtained from the distillation of petroleum are re? nery gas and gasoline. State one use of each of these fractions. re? nery gas ……………………………………………………………………………………………………….. asoline ……………………………………………………………………………………………………….. [2] (c) Ethene is an unsaturated hydrocarbon. What do you understand by the following terms? unsaturated ……………………………………………………………………………………………………….. hydrocarbon …………………………………………………………………………………………………. [2] (d) Ethene is used to make ethanol. (i) Which of these reactions is used to make ethanol from ethene?

Tick one box. catalytic addition of steam fermentation oxidation using oxygen reduction using hydrogen [1] © UCLES 2010 0620/21/O/N/10 [Turn over 14 (ii) Draw the structure of ethanol showing all atoms and bonds. For Examiner’s Use [2] (e) Ethene is used to make poly(ethene). Complete the following sentences about this reaction. Use words from the list below. additions carbohydrates catalysts monomers polymers The ethene molecules which join to form poly(ethene) are the …………………………. . The poly(ethene) molecules formed are …………………………. [2] [Total: 11] © UCLES 2010 0620/21/O/N/10 15 8 Lead(II) bromide can be electrolysed using the apparatus shown below. For Examiner’s Use graphite rod + – graphite rod lead(II) bromide ceramic crucible heat (a) Choose one word from the list below which describes the graphite rods. Put a ring around the correct answer. cations electrodes electrons insulators metals [1] (b) State the name of the products formed during this electrolysis at the negative graphite rod. ……………………………………………………………………………………. he positive graphite rod. ……………………………………………………………………………….. [2] (c) Which of the following conduct electricity? Tick two boxes. ceramic crucible graphite rod molten lead(II) bromide solid lead(II) bromide [2] © UCLES 2010 0620/21/O/N/10 [Turn over 16 (d) The structure of lead(II) bromide is shown below. Pb2+ Br – Pb2+ Br – Pb2+ Br – Br – Br – Br – Br – Pb2+ Br – Pb2+ Br – Br – Br – Pb2+ Br – For Examiner’s Use Write the simplest formula for lead(II) bromide. …………………………………………………………………………………………………………………… [1] (e) Lead(II) bromide is formed as a precipitate when aqueous solutions of lead(II) nitrate and potassium bromide are mixed. (i) What do you understand by the term precipitate ? …………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………… 1] (ii) The formula of lead(II) nitrate is Pb(NO3)2. State the number of different types of atom present in this formula. ……………………………………………………………………………………………………………… [1] (iii) State the total number of oxygen atoms present in this formula. ……………………………………………………………………………………………………………… [1] (iv) Lead compounds are pollutants in the air. State one harmful effect of lead compounds on health. …………………………………………………………………………………………………………….. [1] [Total: 10] © UCLES 2010 0620/21/O/N/10 17 BLANK PAGE © UCLES 2010 0620/21/O/N/10 18 BLANK PAGE © UCLES 2010 0620/21/O/N/10 19 BLANK PAGE © UCLES 2010 0620/21/O/N/10 © UCLES 2010 DATA SHEET The Periodic Table of the Elements Group III 1 I H Hydrogen II IV V VI VII 0 4 He Helium 1 11 12 14 16 19 2 20 7 9 Li Boron Carbon Be 5 27 28 6 B C 7 N Nitrogen O Oxygen F Fluorine Ne Neon Lithium Beryllium 3 4 8 31 32 9 35. 5 10 40 23 24 Na Aluminium Mg 13 48 51 52 55 56 59 59 64 65 70

Al 14 Si Silicon P Phosphorus S Sulfur Cl Chlorine Ar Argon Sodium Magnesium 11 12 15 73 75 16 79 17 80 18 84 39 40 45 K Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Ca 23 91 93 96 101 103 106 108 112 24 25 26 27 28 29 30 Sc Ti V Cr Mn Fe Co Ni Cu Zn 31 Ga Gallium Ge Germanium As Arsenic Se Selenium Br Bromine Kr Krypton Potassium Calcium Scandium Titanium 19 20 21 22 32 115 119 33 122 34 128 35 127 36 131 20 85 88 89 Permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible.

Every reasonable effort has been made by the publisher (UCLES) to trace copyright holders, but if any items requiring clearance have unwittingly been included the publisher will be pleased to make amends at the earliest possible opportunity. University of Cambridge International Examinations is part of the Cambridge Assessment Group. Cambridge Assessment is the brand name of University of Cambridge Local Examinations Syndicate (UCLES), which is itself a department of the University of Cambridge. 0620/21/O/N/10 Rb Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Sr 41 181 184 186 190 192 195 197 42 43 44 45 46 47

Y Zr Nb Mo Tc Ru Rh Pd Ag 48 Cd Cadmium In Indium Sn Tin Sb Antimony Te Tellurium I Iodine Xe Xenon Rubidium Strontium Yttrium Zirconium 37 38 39 40 49 201 204 50 207 51 209 52 53 54 133 137 139 178 Cs Tantalum Iridium Tungsten Rhenium Osmium Platinum Ba 73 77 74 75 76 78 La Ta W Re Os Pt Hf Ir 79 Au Gold Hg Mercury Tl Thallium Pb Lead Bi Bismuth Po Polonium At Astatine Rn Radon Caesium Barium Lanthanum Hafnium 55 56 57 * 72 80 81 82 83 84 85 86 226 227 Fr 140 141 144 150 Ra Ac 152 157 159 162 165 167 169 173 175 Francium Radium Actinium 87 88 89 *58-71 Lanthanoid series 90-103 Actinoid series Ce