2023_ASRJC_H2_Chem_Prelim_P2_QP

ASRJC JC2 PRELIM 2023 9729/02/H2 [Turn over ANDERSON SERANGOON JUNIOR COLLEGE 2023 JC2 PRELIMINARY EXAMINATION NAME:______________________________ ( ) CLASS: 23 / _____ CHEMISTRY 9729/02 Paper 2 Structured Questions 14 September 2023 2 hours Candidates answer on the Question Paper. Additional Materials: Data Booklet READ THESE INSTRUCTIONS FIRST Write your name, class and register 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. Answer all questions in the spaces provided on the Question Paper. The use of an approved scientific calculator is expected, where appropriate. A Data Booklet is provided. The number of marks is given in brackets [ ] at the end of each question or part question. For Examiner’s Use Paper 2 1 /19 2 /9 3 /11 4 /17 5 /19 Total / 75 This document consists of 20 printed pages and 4 blank pages.

2 ASRJC JC2 PRELIM 2023 9729/02/H2 Answer all the questions. 1 The common chlorides of Period 3 elements are shown in Table 1.1. Table 1.1 Period 3 chloride NaCl AlCl3 SiCl4 PCl5 Bonding C Structure S pH of aqueous solution 3 (a) A 3.30 g sample of a Period 3 chloride is heated to 500 K in a sealed flask of 250 cm3. At this temperature, the chloride is a gas and the pressure in the flask is 323 kPa. Assuming the gas behaves ideally, calculate the Mr of the Period 3 chloride. Hence, use the chlorides given in Table 1.1 to deduce its formula. [2] (b) (i) Complete Table 1.1 by • identifying the bonding shown by each chloride under standard conditions. Use C = covalent, I = ionic, M = metallic • identifying the structure shown by each chloride under standard conditions. Use G = giant, S = simple • stating the pH of the aqueous solution of each chloride at 298 K. [3]

3 ASRJC JC2 PRELIM 2023 9729/02/H2 [Turn over (ii) At certain temperature, aluminium chloride exists as A l2Cl6 molecules. Draw the structure of Al2Cl6. State how the shape with respect to each Al atom changes from AlCl3 to Al2Cl6. ………………………………………………………………………………………………. ………………………………………………………………………………………………. ……………………………………………………………………………………………… ………………………………………………………………………………………………. …………………………………………………………………………………...…………. …………………………………………………………………………………………... [2] (iii) SCl2 is also a chloride of Period 3 element. It is a cherry-red liquid that reacts vigorously with water to form a strongly acidic solution. Use this information to deduce the bonding and structure shown by SCl2.