Chemistry Past Paper
Centre No. Candidate No. Paper Reference(s) Surname Paper Reference Initial(s) 7 0 8 1 7081/02 0 2 Signature Examiner’s use only London Examinations GCE Chemistry Ordinary Level Paper 2 Monday 19 January 2009 – Morning Time: 2 hours Team Leader’s use only Question Leave Number Blank 1 2 3 4 5 Materials required for examination Nil Items included with question papers Nil 6 7 8 9 Instructions to Candidates In the boxes above, write your centre number, candidate number, your surname, initial(s) and signature. The paper is arranged in TWO sections, A and B.
In Section A, answer ALL questions in the spaces provided in this question paper. In Section B, answer TWO questions in the spaces provided in this question paper. Indicate which question you are answering by marking the box ( ). If you change your mind, put a line through the box ( ) and then indicate your new question with a cross ( ). Information for Candidates A Periodic Table is printed on the back cover of this question paper. Calculators may be used. The total mark for this paper is 100. Marks for parts of questions are shown in round brackets: e. g. (2). This paper has 9 questions.
All blank pages are indicated. DATA One mole of any gas occupies 24 000 cm3 at room temperature and atmospheric pressure. One mole of electrons carries a charge of 96 500 coulombs or 1 faraday. Advice to Candidates Write your answers neatly and in good English. In calculations, show all the steps in your working. This publication may be reproduced only in accordance with Edexcel Limited copyright policy. ©2009 Edexcel Limited. Total Turn over N29895A W850/U7081/57570 5/5/4/4/1500 Printer’s Log. No. *N29895A0120* Leave blank SECTION A Answer ALL questions in this section.
There is useful data on the front cover and a Periodic Table is printed on the back of this booklet. 1. (a) For the laboratory preparation of dry hydrogen, state the reactants, drying agent and method of collection. Reactants ……………………………………………………………………………………………………….. Drying agent ………………………………………………………………………………………………….. Method of collection ……………………………………………………………………………………….. 3) (b) (i) Write an equation for the combustion of hydrogen in oxygen to form water. ……………………………………………………………………………………………………………….. (1) (ii) Give a chemical test and the result to show that water is the product. ……………………………………………………………………………………………………………….. ……………………………………………………………………………………………………………….. 2) (iii) Give a physical test and the result to show that the water is pure. ……………………………………………………………………………………………………………….. ……………………………………………………………………………………………………………….. (2) (c) Write the equation for the reaction between hydrogen and chlorine and name the gaseous product. Equation …………………………………………………………………………………………………………
Name of product …………………………………………………………………………………………….. (2) (Total 10 marks) Q1 2 *N29895A0220* Leave blank 2. You are provided with solutions of hydrochloric acid, sodium hydroxide, barium chloride and limewater only. In addition, you have a Bunsen burner, test tubes and dropping pipettes but no other apparatus. Describe how you would distinguish between each of the following pairs of substances. Write an equation for any one of the reactions. (a) Aqueous sodium chloride and aqueous sodium sulphate.
Test ……………………………………………………………………………………………………………….. Observation for sodium chloride ………………………………………………………………………. Observation for sodium sulphate ………………………………………………………………………. (3) (b) Aqueous iron(II) chloride and aqueous iron(III) chloride. Test ………………………………………………………………………………………………………………..
Observation for iron(II) chloride ………………………………………………………………………. Observation for iron(III) chloride ……………………………………………………………………… (3) (c) Solid sodium carbonate and solid magnesium carbonate. Test ……………………………………………………………………………………………………………….. ………………………………………………………………………………………………………………………
Observation for sodium carbonate ……………………………………………………………………. Observation for magnesium carbonate ………………………………………………………………. (3) (d) Equation for one of the reactions. ……………………………………………………………………………………………………………………… (1) (Total 10 marks) Q2 *N29895A0320* 3 Turn over Leave blank 3. (a) Crude oil is a raw material in the petrochemicals industry. Short-chain hydrocarbons can be obtained from crude oil as shown below.
Process A fractional distillation hydrocarbon fractions Process B short-chain hydrocarbons crude oil (i) Name two hydrocarbon fractions produced by Process A and give a use for one of them. Fraction 1 name ………………………………………………………………………………………… Use ………………………………………………………………………………………………………….. Fraction 2 name ………………………………………………………………………………………… 3) (ii) Name Process B and state why it is important in the petrochemical industry. ……………………………………………………………………………………………………………….. ……………………………………………………………………………………………………………….. ……………………………………………………………………………………………………………….. ……………………………………………………………………………………………………………….. 2) (iii) Short-chain hydrocarbons are used to make polymers. Draw the structure for poly(ethene). (1) 4 *N29895A0420* Leave blank (b) (i) Draw the structures of two isomers of the alkane C5H12 and name one of them. (3) (ii) Draw the structure of one isomer of the alkene C4H8. (1) (Total 10 marks) Q3 *N29895A0520* 5 Turn over Leave blank 4. For each of the following reactions involving the halogens or their compounds • • • describe what you would see name the halogen-containing product(s) complete and balance the equation for the reaction. (a) Chlorine gas is bubbled through aqueous sodium iodide.
Observation ……………………………………………………………………………………………………. ………………………………………………………………….. …………………………………………………. Names of products ………………………………………………………………………………………….. Equation: Cl2 + NaI (4) (b) Chlorine gas is passed over heated iron in a hard glass tube. Observation ……………………………………………………………………………………………………. …………………………………………………………………………………………………………………….. Name of product …………………………………………………………………………………………….. Equation: Fe + Cl2 (3) (c) Aqueous silver nitrate is added to aqueous sodium bromide. Observation ……………………………………………………………………………………………………. ………………………………………………………………………………………………………………………
Name of product …………………………………………………………………………………………….. Equation: AgNO3 + NaBr (3) (Total 10 marks) Q4 6 *N29895A0620* Leave blank 5. An experiment was performed to investigate the enthalpy change when iron filings are added to copper(II) sulphate solution. 5. 0 g of iron was added to 50. 0 cm3 of copper(II) sulphate solution of concentration 0. 50 mol dm–3 in a polystyrene cup and the mixture was stirred. The rise in temperature was 24. 0 °C. (a) If it is assumed that the mass of the copper(II) sulphate solution is 50. g, it is possible to calculate the energy change by using the formula Energy change (kJ) = mass of solution (kg) ? 4. 2 ? rise in temperature (°C) (i) Calculate the energy change for the amounts of reactants in the cup. ……………………………………………………………………………………………………………….. ……………………………………………………………………………………………………………….. (2) (ii) Calculate the number of moles of copper(II) sulphate in 50. 0 cm3 of the solution and hence calculate the energy change per mole of copper(II) sulphate.
Moles of copper(II) sulphate ……………………………………………………………………………………………………………….. ……………………………………………………………………………………………………………….. Energy change per mole ……………………………………………………………………………………………………………….. ……………………………………………………………………………………………………………….. (3) (iii) Enthalpy change for the reaction (?
H) = ………………………. kJ mol–1 (1) (b) (i) Write the ionic equation for the reaction, including state symbols. ……………………………………………………………………………………………………………….. (2) (ii) Explain, in terms of electron transfer, why this is a redox reaction. ……………………………………………………………………………………………………………….. ……………………………………………………………………………………………………………….. ………………………………………………………………………………………………………………. ……………………………………………………………………………………………………………….. (2) (Total 10 marks) TOTAL FOR SECTION A: 50 MARKS Q5 *N29895A0720* 7 Turn over Leave blank BLANK PAGE 8 *N29895A0820* Leave blank SECTION B Answer TWO questions in this section. If you change your mind, put a line through the box ( ) and then indicate your new question with a cross ( ).
Where appropriate, give equations and diagrams to clarify your answers. If you answer question 6 put a cross in this box 6. . (a) (i) Explain briefly how the difference in a physical property of oxygen and nitrogen enables the two gases to be obtained from air on an industrial scale. Details of the equipment used are not required. ……………………………………………………………………………………………………………….. ……………………………………………………………………………………………………………….. ………………………………………………………………………………………………………………. ……………………………………………………………………………………………………………….. ……………………………………………………………………………………………………………….. ……………………………………………………………………………………………………………….. (4) (ii) State how a lighted spill can be used to distinguish between samples of oxygen and nitrogen. ………………………………………………………………………………………………………………. ……………………………………………………………………………………………………………….. ……………………………………………………………………………………………………………….. (2) (iii) Give the names of two noble gases present in the air and state a use for each of them. ……………………………………………………………………………………………………………….. ………………………………………………………………………………………………………………. ……………………………………………………………………………………………………………….. (2) (iv) Give the name of a gas that is a cause of global warming and write the equation to show how this gas is formed when methane burns in air. ……………………………………………………………………………………………………………….. ………………………………………………………………………………………………………………. (3) *N29895A0920* 9 Turn over Leave blank (b) (i) A nitrogen molecule contains a triple covalent bond. Draw a diagram to show the electron arrangement of the outer shells in a molecule of nitrogen and suggest why the gas is inert at room temperature. ……………………………………………………………………………………………………………….. …………………………………………………………………..
