YSS 4E Pure Chem Paper 2 Prelim 2024

[Turn over YISHUN SECONDARY SCHOOL PRELIMINARY EXAMINATION 2024 SECONDARY 4 EXPRESS CANDIDATE NAME CLASS INDEX NUMBER CHEMISTRY 6092/02 Paper 2 23 August 2024 1 hour 45 minutes Candidates answer on the Question Paper. No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your name, class and index number on 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 one question. Write your answers in the spaces provided. Electronic calculators may be used. 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 24. The use of an approved scientific calculator is expected, where appropriate. This document consists of 24 printed pages.

2 Section A Answer all questions. 1 Use the list of substances to answer the following questions. calcium chloride zinc helium sodium chloride graphite copper sodium copper(II) carbonate You may use each substance once, more than once or not at all. (a) Which substance has a giant covalent structure? .........………………………………………………………………………………………………….[1] (b) Which substance only conducts electricity in molten state? .........………………………………………………………………………………………………….[1] (c) Which substance can be decomposed by heat to give a gaseous product at room temperature and pressure? .........………………………………………………………………………………………………….[1] (d) Which two substances form the alloy brass? .........………………………………………………………………………………………………….[1] (e) Which substance is a noble gas? .........………………………………………………………………………………………………….[1] (f) Which substance can be oxidised by oxygen to form an amphoteric oxide? .........………………………………………………………………………………………………….[1] [total: 6]

3 [Turn over 2 Fig. 2.1 shows two different experimental set up for electroplating an object with silver. Fig. 2.1 (a) Write equations, with state symbols, to show the reactions that happen at the anode and cathode during each experiment. experiment 1 anode: .........…………………………………………………………………………………………… cathode: .........………………………………………………………………………………………… experiment 2 anode: .........…………………………………………………………………………………………… cathode: .........………………………………………………………………………………………[3] (b) At the beginning of each experiment, the student removes a sample of the electrolyte, aqueous silver nitrate, and puts it into separate test tubes. The student then adds a few drop of aqueous sodium chloride to each test tube. Describe and explain what the student would see. .........…………………………………………………………………………………………………..... .........………………………………………………………………………………………………….[1]