Temasek 2024 Prelim O Chem P1 QP

No part of the paper is to be reproduced without the approval of the Principal of Temasek Secondary School. TEMASEK SECONDARY SCHOOL Preliminary Examination 2024 Secondary 4 Express CHEMISTRY 6092/01 Paper 1 Multiple Choice 1 hour Additional Material: Multiple Choice Answer Sheet READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, highlighters, glue or correction fluid. Write your name, index number and class on the Multiple Choice Answer Sheet. There are forty questions on this paper. Answer all questions. For each question there are four possible answers A, B, C and D. Choose the one you consider correct and record your choice in soft pencil on the separate Answer Sheet. Read the instructions on the Answer Sheet very carefully. Each correct answer will score one mark. A mark will not be deducted for a wrong answer. Any rough working should be done in this booklet. A copy of the Periodic Table is printed on page 17. The use of an approved scientific calculator is expected, where appropriate. This document consists of 17 printed pages and 1 blank page.

2 No part of the paper is to be reproduced without the approval of the Principal of Temasek Secondary School. 1 Methanol and ethanoic acid can react to give methyl ethanoate using the set - up below. condenser water methanol and ethanoic acid What is the purpose of the condenser in this set-up? A To prevent the methanol from reacting with the oxygen in the air. B To prevent the methanol and ethanoic acid from escaping from the reaction mixture. C To separate methyl ethanoate from the methanol and ethanoic acid. D To lower the temperature to prevent decomposition of methyl ethanoate. 2 Calcium sulfate can be made by adding 20 cm3 of aqueous calcium nitrate to dilute sulfuric acid. 1 2 3 4 5 Which pieces of apparatus are needed to obtain calcium sulfate from aqueous calcium nitrate and dilute sulfuric acid? A 1, 2 and 4 B 1, 2 and 5 C 2, 3 and 4 D 2, 4 and 5

3 No part of the paper is to be reproduced without the approval of the Principal of Temasek Secondary School. 3 Four statements about a mixture containing X, Y and Z are given. 1 X and Y are miscible liquids. 2 Z is soluble in X but not in Y. 3 Y has a lower boiling point than X or Z. 4 Z will decompose upon heating. Which row correctly lists the steps required to separate all three substances? A fractional distillation → crystallisation B fractional distillation → evaporation to dryness C simple distillation → crystallisation D simple distillation → evaporation to dryness 4 The graph below shows a heating curve as a substance change from the solid to the gaseous state. What is/are the state(s) of the substance in region Z of the graph? A solid only B gaseous only C solid and liquid D gaseous and liquid 5 What happens to the molecules when steam condenses to form water? A The molecules gain energy and move faster. B The molecules lose energy and become smaller. C The molecules lose energy and move closer together. D The molecules gain energy and break up to form atoms. Z temperature / °C time / s

4 No part of the paper is to be reproduced without the approval of the Principal of Temasek Secondary School. 6 Four balloons are filled with equal volume of different gases at the same temperature and pressure. Which balloon will shrink the fastest? 7 The following set-up shows a manometer. Which of the following gas(es) will cause the liquid level in column A to fall? 1 ethane 2 sulfur dioxide 3 carbon monoxide A 2 only B 1 and 2 only C 1 and 3 only D All the above N2 CH4 O2 SO2 A B C D

5 No part of the paper is to be reproduced without the approval of the Principal of Temasek Secondary School. 8 Lithium has a relative atomic mass of 7. It has two stable isotopes with relative masses of 6 and 7 respectively. What can be concluded from these information? A Lithium-6 is radioactive and will decay into lithium-7. B Lithium-6 has different chemical properties compared to lithium-7. C Lithium-6 has a different number of protons compared to lithium-7. D Lithium-6 is found naturally in very small proportions as compared to lithium-7. 9 An ion X3- has m nucleons and n electrons. What does the nucleus of an atom of X contain? number of protons number of neutrons A n m – n B n + 3 m – (n + 3) C n – 3 m – (n – 3) D n – 3 m – n 10 Ammonium ion is found in ammonium chloride. The diagram shows the bonding in an ammonium ion. (Note that only valence electrons are shown.) Which statement about ammonium chloride is not correct? A Five electrons in the nitrogen atom are involved in bonding. B The ammonium ion forms covalent bonds with the chloride ion. C Both covalent and ionic bonds are found in ammonium chloride. D One of the hydrogen atom loses an electron to a chlorine atom.

6 No part of the paper is to be reproduced without the approval of the Principal of Temasek Secondary School. 12 Element X exists as a gaseous molecule X2 at room temperature and pressure. One volume of element X combines with two volumes of hydrogen gas to form 2 volumes of gaseous hydride of X. What is the chemical formula of the hydride of X formed? A HX B H2X C HX2 D H2X2 13 1 g of gaseous hydrocarbon Z has a volume of 54 5 cm3 (measured at room temperature and pressure). What is the possible molecular formula for the gas Z? A C2H4 B C3H4 C C3H8 D C6H8 14 What is the volume of gas produced when 0.1 g of magnesium is reacted with an excess of hydrochloric acid if the percentage yield of the reaction is 80.0%? A 40.0 cm3 B 60.0 cm3 C 80.0 cm3 D 100.0 cm3 11 Rescuers often need to drill through fallen rocks to rescue people trapped in caves. The drill needs lubricating from time to time. Four statements about the materials used for the drill tip and the lubricant are shown below. 1 Diamond is used for the drill tip because it is hard. 2 Diamond is used for the drill tip because it does not conduct electricity. 3 Graphite is used as the lubricant because it conducts electricity. 4 Graphite is used as the lubricant because it is soft and slippery. Which statements are correct? A 1 and 3 B 1 and 4 C 2 and 3 D 2 and 4

7 No part of the paper is to be reproduced without the approval of the Principal of Temasek Secondary School. 15 Which substance will dissolve in water to produce H+ ions? A aluminium oxide B calcium oxide C carbon monoxide D nitrogen dioxide 16 X is a Group 1 element while Y is a transition element. Which of the following states the correct similarity and difference in their properties? similarity difference A X and Y have high melting points. Y is harder than X. B X and Y have high melting points. Y has higher density than X. C X and Y form coloured compounds. X does not conduct electricity while Y conducts electricity. D X and Y are good conductors of electricity. X is soluble in water while Y is insoluble in water. 17 Many properties of an element and its compounds can be predicted from the position of the element in the Periodic Tabl