2022 QSS Chem Prelims P2

NAME: CLASS: INDEX NO: QUEENSWAY SECONDARY SCHOOL PRELIMINARY EXAMINATION 2022 SECONDARY 4 EXPRESS CHEMISTRY 6092/02 Paper 2 13 September 2022 1 hour 45 minutes No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your name and index number on all the work you hand in. Write in dark blue or black pen. You may use an HB pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. Section A: Answer all questions in the spaces provided. Section B: Answer all three questions, the last question is in the form either/or. Answer all questions in the spaces provided. 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. A copy of the Periodic Table is printed on page 25. The use of an approved scientific calculator is expected, where appropriate. This document consists of 25 printed pages. Setters: Ms Tong and Ms How [Turn over For Examiner's Use Section A /50 Q9 /12 Q10 / 8 E / O Q11 /10 TOTAL /80 Parent’s Signature:

2 SECTION A Answer all the questions in this section in the spaces provided. The total mark for this section is 50. A1 Atoms or ions that contain the: • same number of electrons are isoelectronic particles; • same number of neutrons are isotonic particles; and • same number of protons are isoprotic particles. The nuclide notations of five ions are given below. (a) Which of the five ions are (i) isoelectronic; ………………………………………………………………………………….… [1] (ii) isotonic; and ………………………………………………………………………………….… [1] (iii) isoprotic? ………………………………………………………………………………….… [1] (b) A beam of charged particles is deflected when they passed through an electric field. Particles with higher charge and lower mass are deflected more. When passed through an electric field, which of the five ions would be deflected the (i) most? ………………………………………………………………………………….… [1] (ii) least? ………………………………………………………………………………….… [1] [Total: 5]

3 A2 The table below shows the melting points of some aluminium compounds. aluminium compound melting point / oC Al2O3 2072 AlF3 1291 AlCl3 180 (a) With reference to the melting points given, suggest the structure and bonding of aluminium chloride. structure ……………………………...……………………………………………………. bonding ………………………………………………………………..……………….. [1] (b) (i) Draw the ‘dot-and-cross’ diagram for aluminium oxide. Show outer electrons only. [2] (ii) Explain why the melting point of aluminium oxide is higher than that of aluminium fluoride. ……………………………………………………………………………………….. ……………………………………………………………………………………….. ………………………………………………………………………………….… [1] (iii) Describe and explain one other physical property of aluminium oxide. ………………………………