Temasek 2024_Prelim_O_Chem_P2_SectA_QP

Name: Index Number: Class: _______ TEMASEK SECONDARY SCHOOL Preliminary Examination 2024 Secondary 4 Express CHEMISTRY 6092/02 Paper 2 (Section A) Total duration for Sections A and B: 1 hour 45 minutes Candidates answer on the Question Paper. No additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your name, index number and class 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. At the end of the examination, submit Section A and B separately. 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 7 in Section B. The use of an approved scientific calculator is expected, where appropriate. FOR EXAMINER'S USE Section A /70 This document consists of 20 printed pages and 2 blank pages.

2 No part of the paper is to be reproduced without the approval of the Principal of Temasek Secondary School. Section A Answer all the questions in this section in the spaces provided. The total mark for this section is 70. A1 The list below shows the chemical formulae of some substances. (NH4)2SO4 Ag2CO3 NaBr ZnCl2 CaCl2 FeSO4 Al2O3 KNO3 SiO2 Use the list to answer the questions below. The substances can be used once, more than once, or not at all. (a) State one substance that is coloured. ……………………………………………………………………………... [1] (b) State one substance that reacts with both an acid and an alkali. ……………………………………………………………………………... [1] (c) State one substance that can be prepared by precipitation. ……………………………………………………………………………... [1] (d) State one substance that is commonly used as a fertiliser. ……………………………………………………………………………... [1] (e) State one substance that is used as a catalyst in the cracking of large hydrocarbons into useful shorter fractions. ……………………………………………………………………………... [1] [Total: 5]

3 No part of the paper is to be reproduced without the approval of the Principal of Temasek Secondary School. A2 Fig. 2.1 shows the arrangement of the apparatus for an experiment that is carried out to study the reactivity of metals. Fig. 2.1 Table 2.1 shows the results obtained from the experiment using metal electrodes P, Q, R and S. Table 2.1 pair of metal electrodes voltmeter reading/ V negative terminal Q and R 2.7 metal Q R and S 1.1 metal S S and P 0.3 metal S Q and S X metal Q P and R 0.8 metal P (a) Explain, in terms of structure and bonding, why the metal electrodes can conduct electricity. ………………………...…………………………………………………... ………………………...…………………………………………………...