2025 Prelim P2 QP_(for exchange)_H2 Chem_HCI

This document consists of 20 printed pages and 2 blank pages. HWA CHONG INSTITUTION C2 Preliminary Examination Higher 2 CANDIDATE NAME CT GROUP 2 4 S CENTRE NUMBER S INDEX NUMBER CHEMISTRY Paper 2 Structured Questions 9729/02 3 September 2025 2 hours Candidates answer on the Question Paper. Additional Materials: Data Booklet READ THESE INSTRUCTIONS FIRST Write your name, CT group, centre number and index number on all the work you hand in. Write in dark blue or black pen. You may use a HB pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. DO NOT WRITE ON ANY BARCODES. Answer all questions in the spaces provided in the Question Paper. The use of an approved scientific calculator is expected, where appropriate. A Data Booklet is provided. For Examiner’s Use 1 / 10 2 / 18 3 / 14 4 / 14 5 / 19 Deductions (s.f.) Deductions (units) Deductions (structures) Total / 75

2 © Hwa Chong Institution 2025 9729/02/C2 Preliminary Examination DO NOT WRITE IN THIS MARGIN DO NOT WRITE IN THIS MARGIN DO NOT WRITE IN THIS MARGIN DO NOT WRITE IN THIS MARGIN DO NOT WRITE IN THIS MARGIN [Turn Over Answer all questions in the space provided. 1 (a) In Fig.1.1, sketch a graph to show the variation of ionic radius across Period 3. Explain the shape of your graph. Na Mg Al Si P S Cl Fig.1.1 ……………………………………………………….…………………………………………..….……… ……………………………………………………….…………………………………………..….……… ……………………………………………………….………………………………………..…….……… ……………………………………………………….………………………………………...…….…….. ……………………………………………………….………………………………………..…….……… ……………………………………………………….………………………………………..…….……… ……………………………………………………….………………………………………...…….…….. ……………………………………………………….………………………………………..…….……… ……………………………………………………….……………………………………….……….… [3] (b) Write an equation for the reaction of P4O10 with water. State the pH of the resulting mixture. equation …...……………………..……………………….……………………………………….……… pH ..………………………………..……...………….…………………………………….……...…… [1] (c) Describe the acid-base behaviour of A l2O3 by reference to its reaction separately with sulfuric acid, H2SO4, and with sodium hydroxide, NaOH. Write equations for any reactions described. ……………………………………………………….………………………………………..…….……… ……………………………………………………….………………………………………...…….…….. ……………………………………………………….………………………………………..…….……… ……………………………………………………….……………………………………….……….… [2] ionic radius

3 © Hwa Chong Institution 2025 9729/02/C2 Preliminary Examination DO NOT WRITE IN THIS MARGIN DO NOT WRITE IN THIS MARGIN DO NOT WRITE IN THIS MARGIN DO NOT WRITE IN THIS MARGIN DO NOT WRITE IN THIS MARGIN [Turn Over (d) Aluminium chloride, AlCl3, and beryllium chloride, BeCl2, can act as Lewis acids. (i) Explain what is meant by a Lewis acid. ………………………………………………………