Broadrick Prelim P2

1 6092/2/8/24 Name Class Index Number BROADRICK SECONDARY SCHOOL SECONDARY 4 EXPRESS PRELIMINARY EXAMINATION 2024 CHEMISTRY Paper 2 Candidates answer on Question Paper No Additional Materials are required. 6092/02 August 2024 1 hour 45 minutes READ THESE INSTRUCTIONS FIRST Write your name, class and index number on all the work you hand in. Write in dark blue or black pen on both sides of the paper. You may use a pencil for any diagrams or graphs, tables or rough working. Do not use staples, paper clips, highlighters, glue or correction fluid. Section A [70 marks] Answer all questions in the spaces provided. Section B [10 marks] Answer one question from this section. Write your answers in the spaces provided on the question paper. The number of marks is given in brackets [ ] at the end of each question or part question. A copy of the Periodic Table is printed on page 23. The use of an approved scientific calculator is expected, where appropriate. FOR EXAMINER’S USE Section A / 70 Section B / 10 Total / 80 This document consists of 23 printed pages including this page

2 [Turn Over 6092/2/8/24 Section A Answer all questions. 1 Choose from the following compounds to answer the questions. Each compound may be used once, more than once or not at all. For Examiner’s Use (a) State which compound: (i) reacts with hydrogen gas at 150 oC, in the presence of nickel catalyst …………………………… [1] (ii) can be oxidised to form propanoic acid …………………………… [1] (iii) is an isomer of butane …………………………… [1] (iv) is an unsaturated hydrocarbon. …………………………… [1] (b) Identify the two compounds that will turn moist blue litmus red. …………………………… and …………………………… [1] [Total: 5]

3 [Turn Over 6092/2/8/24 2 (a) The table shows information on five different particles. particle number of protons number of electrons number of neutrons P 19 19 20 Q 19 19 19 R 9 10 10 S 9 9 9 T 8 10 10 For Examiner’s Use (i) Explain why particle T is an ion. ……………………………………………………………..…………………………………... [1] (ii) Identify the two particles that are isotopes. ………………………… and ………………………… [1] (b) A sample of Krypton was found during a space mission. Experiments were conducted on the sample and the following information was obtained. relative isotopic mass percentage abundance 80 2 82 12 83 12 84 57 85 17 Calculate the relative atomic mass of the sample of Krypton and give your answer to three significant figures. relative atomic mass = …………………… [1] [Total: 3]

4 [Turn Over 6092/2/8/24 3 The table below shows the physical properties of four substances. substance melting point / oC boililng point / oC electrical conductivity phosphorus trichloride -94 76 poor diamond 3550 4830 poor calcium oxide 2570 2850 poor in solid state, good in aqueous state sodium oxide 1130 1950 For Examiner’s Use (a) Which substance(s) exist(s) as a solid at 2000 oC? ………………………………..……………………………...………………………………..……..… [1] (b) Describe the arrangement and motion of phosphorus trichloride molecules at 0 oC. ………………………………..……………………………...………………………………..……..… ………………………………..……………………………...………………………………..……..… ………………………………..……………………………...………………………………..……..… [2] (c) Explain why calcium oxide has a higher melting point as compared to sodium oxide. ………………………………..……………………………...………………………………..……..… ………………………………..……………………………...………………………………..……..… ………………………………..……………………………...………………………………..……..… ………………………………..……………………………...………………………………..……..… [2] (d) With reference to structure and bonding, explain why diamond is a poor conductor of electricity. ………………………………..……………………………...………………………………..……..… ………………………………..……………………………...………………………………..……..… ………………………………..……………………………...………………………………..……..… [2] [Total: 7]

5 [Turn Over 6092/2/8/24 4 The diagram describes some of the substances that result from the chemical reactions with solid M. For Examiner’s Use (a) Name the following compounds. M: ............................................................ N: ............................................................. O: ............................................................. P: ............................................................. [4] (b) Write the balanced ionic equation for the reaction between solid M and dilute hydrochloric acid. ………………………………..……………………………...………………………………..……..… [2] [Total: 6] solid M add dilute hydrochloric acid solution O green precipitate P insoluble in excess reagent gas N add aqueous sodium hydroxide + gas evolved formed white precipitate in limewater green precipitate P insoluble in excess reagent add aqueous ammonia

6 [Turn Over 6092/2/8/24 5 A scientist added 24.00 cm3 of 0.75 mol/dm3 dilute nitric acid to 23.5 g of potassium oxide. K2O + 2HNO3  2KNO3 + H2O For Examiner’s Use (a) Calculate the number of moles of dilute nitric acid added by the scientist. number of moles = …………………………… mol [1] (b) Determine the limiting reactant. Workings should be clearly shown. limiting reactant: ……………………….………….. [3] (c) Assuming that all of the water produced is evaporated to form water vapour. Calculate the volume of water vapour produced at room temperature and pressure. volume = …………………………… cm3 [2] [Total: 6]

7 [Turn Over 6092/2/8/24 6 The table below shows the boiling point and melting point of three halogens. They are chlorine, bromine and iodine. halogen melting point / oC boiling point / oC -7 59 -103 -34 113 185 For Examiner’s Use (a) Complete the table above by filling in the names of the halogens. [1] (b) In an experiment involving a solution of colourless potassium bromide, some fluorine gas was bubbled into the solution. After a while, the solution turns reddish-brown. Explain why did the solution turn reddish-brown. ………………………………..……………………………...………………………………..……..… ………………………………..……………………………...………………………………..……..… ………………………………..……………………………...………………………………..……..… [2] (c) A student commented that among the three halogens, chlorine, bromine and iodine, iodine has the most metallic character. Do you agree with the comment? Explain your answer. ………………………………..……………………………...………………………………..……..… ………………………………..……………………………...………………………………..……..… ………………………………..……………………………...………………………………..……..… [2] [Total: 5]

8 [Turn Over 6092/2/8/24 7 A student conducted some experiements to study the compounds sodium chloride and calcium chloride. For Examiner’s Use (a) In the first experiment, both compounds were dissolved in water to study the enthalpy change for dissolving. The diagrams below show the energy changes when sodium chloride and calcium chloride are dissolved in water. Describe the differences in energy changes and temperature changes that happen as each compound dissolves. ………………………………..……………………………...………………………………..……..… ………………………………..……………………………...………………………………..……..… ………………………………..……………………………...………………………………..……..… ………………………………..……………………………...………………………………..……..… ………………………………..……………………………...………………………………..……..… ………………………………..……………………………...………………………………..……..… ………………………………..……………………………...………………………………..……..… [4]

9 [Turn Over 6092/2/8/24 (b) In another experiment, electrolysis was conducted using conce