SRJC_H2_CHEM_P2

SRJC 2009 9746/02/PRELIM/2009 [Turn Over SERANGOON JUNIOR COLLEGE General Certificate of Education Advanced Level Higher 2 CANDIDATE NAME CLAS S INDEX NUMBER CHEMISTRY 9746/02 Preliminary Examination 26 August 2009 Paper 2 Structured 1 hr 30min Additional Materials: Data Booklet Writing Papers Candidates answer on the Question Paper. READ THESE INSTRUCTIONS FIRST Write your name and class on all the work you hand in. You may use a soft pencil for any diagrams, graphs or rough work. Answer all questions in the space provided. At the end of the examination, fasten all your work securely together. The number of marks is given in the brackets [ ] at the end of each question or part questions. For Examiner’s Use 1 2 3 4 5 Total This document consists of 12 printed pages and 0 blank page

For 2 Examiner’s Use SRJC 2009 9746/02/PRELIM/2009 [Turn Over 1 The atomic and cationic radii of Period 3 elements, Na to C l, are plotted in the graph below, in order of increasing atomic number. Na Mg Al Si P S ClNa+ Mg2+ Al3+ Si4+ 0.00 10 11 12 13 14 15 16 17 18 Radius / nm Proton no. Atomic & Ionic Radii vs. Proton no. for Elements in Period 3 P3- S2- Cl- 0. 05 0.10 0.15 0.20 0.25 Atomic Radii Cationic Radii Anionic Radii (a) Explain each of the following: (i) The atomic radius decreases across the period from Na to Cl. ………………………………………………………………………………… ………………………………………………………………………………… ………………………………………………………………………………… ………………………………………………………………………………… (ii) The cationic radius of Na+ is smaller than its atomic radius. ………………………………………………………………………………… ………………………………………………………………………………… ………………………………………………………………………………… ………………………………………………………………………………… ………………………………………………………………………………… [4]

3 For Examiner’s Use (b) (i) Indicate, on the graph, the relative positions of the ions, P3–, S2– and Cl–. (ii) Explain your answer in (b)(i). ………………………………………………………………………………… ………………………………………………………………………………… ………………………………………………………………………………… ………………………………………………………………………………… [3] (c) (i) Write down the electronic configuration of sulphur in its ground state. ………………………………………………………………………………… (ii) Explain the following phenomenon: Sulphur can react with fluorine to form SF2, SF4 and SF6 but oxygen can react with fluorine to form OF 2 only. ………………………………………………………………………………… ………………………………………………………………………………… ………………………………………………………………………………… [2] (d) The successive ionisation energies in kJ mol –1 of an element A are as follows: 740, 1500, 7700, 10500, 13600, 18000, 21700 State the Grou