2022 LVSS Chem Prelims P2

LOYANG VIEW SECONDARY SCHOOL Preliminary Examination 2022 Secondary Four Express CANDIDATE NAME : ……………………………………………………………….......... CLASS : …………………. INDEX NUMBER : ……………. CHEMISTRY 6092/02 Paper 2 Theory 29 August 2022 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 all the work you hand in. Write in dark blue or black pen on both sides of the paper. You may use an HB pencil for any diagrams or graphs. Do not use staples, paper clips, highlighters, glue or correction fluid. Section A Answer all questions. Section B Answer all three questions. The last question is in the form either/or. Answer all questions in the spaces provided. 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 21. The use of an approved scientific calculator is expected, where appropriate. Setter: Mrs Lam-Tan Siok Hiang For Examiner’s Use Section A / 50 Section B / 30 Total / 80 This paper consists of 21 printed pages.

2 Section A Answer all questions in this section in the spaces provided. The total mark for this section is 50. 1 Iron is extracted from iron ore in the blast furnace. The equations A, B, C, D and E show some reactions that happen in the blast furnace. A C + O2 → CO2 B CO2 + C → 2CO C Fe2O3 + 3CO → 2Fe + 3CO2 D CaCO3 → CaO + CO2 E SiO2 + CaO → CaSiO3 (a) Use the letters A, B, C, D and E to answer the following questions. Each letter can be used once, more than once or not at all. (i) Which equation shows neutralisation? ………………………………………………………………………….……….. [1] (ii) Which equation shows an element that undergoes both oxidation and reduction at the same time? ………………………………………………………………………….……….. [1] (iii) Which equation shows no change in the oxidation state of any element in the reactants? ………………………………………………………………………….……….. [1] (b) Blast furnace slag may contain impurities of Group IV and Group V oxides. These impurities cause the slag to be less effective in removing acidity from the soil. Explain why Group IV and Group V oxides are less effective in removing acidity. …………………………………………………………………………………………... …………………………………………………………………………………………... [1] [Total: 4]

3 2 Two students want to distinguish between two unlabelled test tubes each containing either aqueous sodium hydroxide or aqueous ammonia. Student A suggests adding aqueous zinc nitrate while student B suggests adding aqueous lead(II) nitrate into both test tubes. (a) Which student would be able to distinguish between the two unlabelled test tubes? Use the observations obtained by both students to support your answer. ………………………………………………………………………………...………… …………………………………………………………………...……………………… …………………………………………………………………...……………………… ………………………………………………………...……………………………