ADSS Prelim P2

This question paper consists of 22 printed pages including this cover page. ADMIRALTY SECONDARY SCHOOL SUBJECT : Chemistry CODE/PAPER : 6092/2 LEVEL/STREAM : Secondary 4 Express DATE : 21 August 2024 TIME : 0800h – 0945h DURATION : 1 hour 45 minutes 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. Section A Answer all questions. Write your answers in the spaces provided. Section B Answer one question. Write your answers in the spaces provided. A copy of the Periodic Table is printed on page 22. The number of marks is given in brackets [ ] at the end of each question or part question. The use of an approved scientific calculator is expected, where appropriate. DO NOT TURN OVER THIS PAPER UNTIL YOU ARE TOLD TO DO SO. PRELIMINARY EXAMINATION 2024 For Examiner’s Use Section A / 70 Section B / 10 Total / 80 NAME: NO: CLASS:

2 Section A Answer all questions. 1 Table 1.1 shows the structures of substances A, B and C. A B C Table 1.1 Use the letters A, B and C to answer the following. Each compound may be used once, more than once or not at all. Answer the following questions using the structure and bonding of the identified substance. (a) State the substance that can be used as an electrode in electrolysis. ……………………………………………………………………………………………. ……………………………………………………………………………………………. ……………………………………………………………………………………………. ……………………………………………………………………………………………. [3] (b) State the substance that is a liquid at room temperature. ……………………………………………………………………………………………. ……………………………………………………………………………………………. ……………………………………………………………………………………………. ……………………………………………………………………………………………. [3]

3 (c) State which substance can be used as a lubricant. ……………………………………………………………………………………………. ……………………………………………………………………………………………. ……………………………………………………………………………………………. ……………………………………………………………………………………………. [3]

4 2 The Haber process is the main industrial procedure for the production of ammonia today. In this process, ammonia is made by reacting nitrogen and hydrogen. N2(g) + 3H2(g) 2NH3(g) A smaller scale of this reaction can be performed in the laboratory using the set-up shown in Fig. 2.1. Fig. 2.1. Nitrogen and hydrogen gas are passed forward and backward over the iron wool until no further reaction is observed. (a) Suggest a reason why air must not be present in the reaction mixture. ……………………………………………………………………………………………. ……………………………………………………………………………………………. [1] (b) Explain the role of the iron wool in this reaction. ……………………………………………………………………………………………. ……………………………………………………………………………………………. [1