2022 HYSS Chem Prelims P2

Name Index Number Class HUA YI SECONDARY SCHOOL Preliminary Examination 2022 CHEMISTRY 6092/2 Paper 2 23 August 2022 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 a pencil for any diagrams, graphs, tables or rough working. Do not use staples, paper clips, highlighters, glue or correction fluid. Section A Answer all questions. Write your answers in the spaces provided on the question paper. Section B Answer all three questions, the last question is in the form of either/or. Answer all the questions in the spaces provided on the question paper. 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. For Examiner’s Use Section A Section B B7 B8 B9 Total This document consists of 24 printed pages including the cover page. © HYSS 2022 No part of this document may be reproduced in any form or transmitted in any form or by any means without the prior permission of Hua Yi Secondary School. [Turn Over] Setter: Ms Keziah Seow 4E 4E

4E Chemistry P2 Preliminary Exam 2022 Hua Yi Secondary School 2 Section A Answer all the questions in this section in the spaces provided. The total mark for this section is 50. A1 The symbols of the elements of Period 3 of the Periodic Table are shown. Na Mg Al Si P S Cl Ar Answer the following questions about these elements. (a) Write the symbol of an element which (i) forms an amphoteric oxide, ………………………………………………………………………………………………. [1] (ii) exists as diatomic molecules, ………………………………………………………………………………………………. [1] (iii) shows both metallic and non-metallic character, ………………………………………………………………………………………………. [1] (iv) is used to fill light bulbs, ………………………………………………………………………………………………. [1] (v) can conduct electricity in solid state and floats on water. ………………………………………………………………………………………………. [1] (b) The oxides of sulfur and silicon have very different melting points. Explain how and why the melting points of sulfur dioxide and silicon dioxide are different. ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… [3] [Total: 8]

4E Chemistry P2 Preliminary Exam 2022 Hua Yi Secondary School 3 A2 The first ionisation energy of elements is the energy required for one mole of gaseous atoms to lose one mole of electrons, forming one mole of gaseous ions with a charge of 1+. The reaction can be described by the equation below, where M represents an atom. M(g) → M+(g) + e- Fig. 2.1 shows the first ionisation energy of Group I elements. Fig. 2.1 Table 2.2 shows some information about atomic radii of Group I elements. Table 2.2 element atomic radius /pm lithium 152 sodium 186 potassium 231 rubidium 244 caesium 262 0 100 200 300 400 500 600 lithium sodium potassium rubidium caesium first ionisation energy (kJ/mol) element

4E Chemistry P2 Preliminary Exam 2022 Hua Yi Secondary School 4 (a) Describe the trend in the first ionisation energy down Group I and use Table 2.2 to explain this trend. ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… [3] (b) Using Fig. 2.1, compare the reactivities of sodium and potassium. Explain your answer. ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… [2] (c) Lithium contains two isotopes, lithium-6 and lithium-7. Do you think that the first ionisation energy of both the isotopes is the same? Explain your answer. ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… [1] (d) Among the elements in the Periodic Table, neon has one of the highest first ionisation energy of 2080 kJ/mol. Suggest a reason why neon has a very high first ionisation energy. ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… [1] [Total: 7]

4E Chemistry P2 Preliminary Exam 2022 Hua Yi Secondary School 5 A3 ‘Lean burn’ engines are a type of car engine. This table shows some information about lean burn engines compared to normal car engines. type of engine amount of air mixed with petrol operating temperature concentration of CO in exhaust gases concentration of NO in exhaust gases normal less air higher higher higher lean burn more air lower lower lower (a) (i) How is nitrogen monoxide formed in a car engine? ...……….…………………………………………………………………………………… ...……….…………………………………………………………………………………… [1] (ii) Suggest why lean burn engines produce smaller amounts of nitrogen monoxide. ...……….…………………………………………………………………………………… ...……….…………………………………………………………………………………… [1] (b) (i) How is carbon monoxide formed in a car engine? ...……….…………………………………………………………………………………… ...……….…………………………………………………………………………………… [1] (ii) Suggest why lean burn engines produce smaller amounts of carbon monoxide. ...……….…………………………………………………………………………………… ...……….…………………………………………………………………………………… [1] (c) The catalytic converter removes pollutant gases. (i) Construct a balanced chemical equation to show how the carbon monoxide and nitrogen monoxide are converted to harmless gases in the catalytic converter. ...……….…………………………………………………………………………………… [1] (ii) When catalytic converters were first available, some advertisements claimed they ‘solved all car pollution problems’. Explain why this is not true. ...……….…………………………………………………………………………………… ...……….…………………………………………………………………………………… [1]

4E Chemistry P2 Preliminary Exam 2022 Hua Yi Secondary School 6 (d) Sulfur dioxide is another common air pollutant. Sulfur dioxide can be detected by bubbling a sample of polluted air into aqueous acidified potassium manganate(VII). 5SO2(g) + 2MnO4-(aq) + 2H2O(l) → 5SO42-(aq) + 2Mn2+(aq) + 4H+(aq) A 5.00 dm3 sample of polluted air was found to contain 2.5% by volume of sulfur dioxide measured at room temperature and pressure. A solution of 0.200 mol/dm3 of manganate(VII) ions was used to test for the presence of sulfur dioxide gas. Calculate the minimum volume of this solution that will be needed to