UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS International General Certificate of Secondary Education CHEMISTRY 0620/02

Paper 2 May/June 2008 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 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 fluid. DO NOT WRITE IN ANY BARCODES Answer all questions. A copy of the periodic table is printed on page 16. 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. www.theallpapers.com 2 © UCLES 2008 0620/02/M/J/08 For Examiner's Use 1 The diagram shows the structures of some substances containing carbon. O C O C C H H H H C H H HH H C COH H H H H C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C Ca2+ CO2– 3 Ca2+ CO2– 3 CO2– 3 Ca2+ Ca2+ CO2– 3 CO2– 3 Ca2+ Ca2+ CO2– 3 Ca2+ CO2– 3 CO2– 3 Ca2+ Ca2+ CO2– 3 CO2– 3 Ca2+ AB C DE F (a) Answer these questions using the letters A, B, C, D, E or F. (i) Which one of these structures is ionic? [1] (ii) Which one of these structures represents ethanol? [1] (iii) Which one of these structures represents a gas which turns limewater milky? [1] (iv) Which one of these structures is an unsaturated hydrocarbon? [1] (b) Describe a chemical test for an unsaturated hydrocarbon. test result [2] www.theallpapers.com 3 © UCLES 2008 0620/02/M/J/08 [Turn over For Examiner's Use (c) State the chemical name of structure B. [1] (d) Structure F has several uses. Which one of the following is a correct use of structure F? Tick one box. for cutting metals as a lubricant for filling balloons as an insulator [1] (e) The structures A to E are compounds. What do you understand by the term compound? [1] (f) State the type of bonding in structure A. [1] [Total: 10] www.theallpapers.com 4 © UCLES 2008 0620/02/M/J/08 For Examiner's Use 2 The diagram shows a statue in a park in an industrial town. The statue is made from limestone. iron pins inside statue statue when first erected the same statue after 20 years (a) State the name of the chemical present in limestone. [1] (b) Use ideas about the chemistry of atmospheric pollutants to suggest how and why the statue changes over 20 years. [4] (c) Parts of the statue are joined together with iron pins. After 30 years, the arm falls off the statue. Suggest why the arm falls off. [1] www.theallpapers.com 5 © UCLES 2008 0620/02/M/J/08 [Turn over For Examiner's Use (d) Iron has several isotopes. (i) What do you understand by the term isotopes? [1] (ii) The table shows the number of subatomic particles in an atom of iron. type of particle number of particles relative charge on the particle electron 26 neutron 30 proton 26 Complete the table to show the relative charge on each particle. [3] (iii) State the number of nucleons in this isotope of iron. [1] (e) Some isotopes are radioactive. State one industrial use of radioactive isotopes. [1] (f) Iron reacts with very dilute nitric acid. Fe + 2HNO3 Fe(NO3)2 + H2 Write a word equation for this reaction. [1] [Total: 13] www.theallpapers.com 6 © UCLES 2008 0620/02/M/J/08 For Examiner's Use 3 The table shows the concentration of some ions present in seawater. name of ion formula of ion concentration of ion in g/dm3 bromide Br – 0.07 calcium Ca2+ 0.4 chloride Cl – 19.1 magnesium Mg2+ 1.2 potassium K+ 0.3 sodium Na+ 10.6 2− SO4 0.8 (a) Which negative ion has the highest concentration in seawater? [1] (b) State the name of the ion with the formula 2− SO4 . [1] (c) Which two ions in the table are formed from Group I elements? and [1] (d) When seawater is evaporated a number of different compounds are formed. State the name of the compound which is present in the greatest quantity. [1] (e) State the names of two ions in the table which move to the cathode when seawater is electrolysed. and [2] www.theallpapers.com 7 © UCLES 2008 0620/02/M/J/08 [Turn over For Examiner's Use (f) When concentrated seawater is electrolysed, chlorine is formed at one of the electrodes. (i) To which Period in the Periodic Table does chlorine belong? [1] (ii) Draw the electronic structure of a chlorine molecule. Show only the outer electrons. [2] (g) Drinking water can be obtained by purifying seawater. Explain why distillation rather than filtration is used to purify seawater for drinking. [2] [Total: 11] www.theallpapers.com 8 © UCLES 2008 0620/02/M/J/08 For Examiner's Use 4 The diagram shows a water treatment works. water in to homes chlorine added aluminium sulphate added sedimentation tank sand filter (a) State one use of water in industry. [1]