2023 HYSS Chem Prelims P1

Name: Index Number: Class: HUA YI SECONDARY SCHOOL Preliminary Examination CHEMISTRY Paper 1 24 August 2023 1 hour Candidates answer on the Multiple Choice Answer Sheet Additional Materials: Multiple Choice Answer Sheet READ THESE INSTRUCTIONS FIRST Write your Name, Index Number and Class on all the work you have done. Write in soft pencil. Do not use staples, paper clips, highlighters, glue or correction fluid. 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. For Examiner’s Use Paper 1 This document consists of 17 printed pages including the cover page. © HYSS 2023 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 4E 4E 6092/1 Setter: Mrs Magdalena Sii

2 2023 4E Pure Chemistry Preliminary P1 Hua Yi Secondary School 1 Which apparatus is the most suitable to measure 37.7 cm3 of a solution accurately? A beaker B burette C measuring cylinder D pipette 2 The diagrams show the chromatograms of an ink sample P using two different solvents. Which substance does ink P contain? A X only B X and Z only C Y and Z only D X, Y and Z 3 The properties of some substances are shown in the table. T R S U melting point/ ⁰C 3600 -101 4000 714 boiling point/ ⁰C 4200 -34 4830 1412 electrical conductivity yes no no yes soluble in water no no no yes Which row identifies the correct substance? magnesium chloride diamond graphite chlorine A T U R S B T S U R C U T R S D U S T R developed with water developed with alcohol P X Y Z P X Y solvent front starting line Z

3 2023 4E Pure Chemistry Preliminary P1 Hua Yi Secondary School 4 Which diagram shows the correct way to obtain dry carbon dioxide, CO2, from a mixture of damp ammonia and carbon dioxide gas? A B C D 5 The following describes the reactions between a sample of solution X and various reagents. test result add aqueous sodium hydroxide drop- wise and then in excess white precipitate forms that is insoluble in excess sodium hydroxide add aqueous ammonia drop-wise and then in excess no precipitate is formed heat with aluminium foil and sodium hydroxide effervescence of colourless, pungent gas that turns moist red litmus paper blue What is solution X? A ammonium chloride B calcium nitrate C lead(II) nitrate D nitric acid damp gases damp gases damp gases damp gases water water concentrated sulfuric acid concentrated sulfuric acid concentrated sulfuric acid concentrated sulfuric acid water water dry CO2 dry CO2 dry CO2 dry CO2

4 2023 4E Pure Chemistry Preliminary P1 Hua Yi Secondary School 6 Which pair of gases would diffuse at the same rate, under the same temperature and pressure? A carbon dioxide and oxygen B oxygen and methane C oxygen and nitrogen D nitrogen and ethene 7 A sample of Y was analysed and found to contain only two isotopes, Y-63 and Y-65. The graph below shows the relative abundances of the two isotopes. What is the relative atomic mass of Y? A 63.2 B 63.4 C 63.6 D 64.0 8 The structural formula of asparagine, a protein, is shown. What is the total number of valence electrons not involved in bonding in the nitrogen and oxygen atoms? A 6 B 8 C 16 D 20 C H H2N COOH CH2 C O NH2 relative charge 63 65 70 30 mass/charge ratio

5 2023 4E Pure Chemistry Preliminary P1 Hua Yi Secondary School 9 Compound Y has the chemical formula Y2H4. The dot-and-cross diagram is shown. Which group of the Periodic Table does element Y belong? A Group V B Group VI C Group VII D Group 0 10 The structure of fullerene, C60, is shown. Which of the following statements is true? A Fullerene is a giant covalent compound. B During melting and boiling, a large amount of energy is used to overcome the strong covalent bonds between carbon atoms. C Fullerene has high thermal conductivity. D Fullerene is an allotrope of carbon. carbon Y Y H H H H

6 2023 4E Pure Chemistry Preliminary P1 Hua Yi Secondary School 11 The structural formula of caffeine is shown. What is the empirical formula of caffeine? A CHNO B C4H5N2O C CH3NCOCNCH3CHNCNCH3CO D C7H10N4O2 12 Trinitrotoluene, also known as TNT, is a chemical used to make explosives. TNT has the chemical formula C6H2(NO2)3CH3. What is the percentage by mass of nitrogen in TNT? [Ar: C, 12; H, 1; N, 14; O, 16] A 10.4% B 18.5% C 25.8% D 30.8% 13 Hexane undergoes complete combustion as shown in the equation. 2C6H14(g) + 19O2(g) → 12CO2(g) + 14H2O(g) Which volume of gaseous product, at room temperature and pressure, is produced when 0.2 mol of hexane is burnt completely? A 2.6 dm3 B 28.8 dm3 C 33.6 dm3 D 62.4 dm3 N N N N O C C C C C H O CH3 CH3 H3C

7 2023 4E Pure Chemistry Preliminary P1 Hua Yi Secondary School 14 When heated strongly, the oxide of element Z decomposes. 2Z3O4(s) → 6ZO(s) + O2(g) When 10 g of Z3O4 is heated strongly, 0.233 g of oxygen is evolved. What is the relative atomic mass, Ar, of element Z? A 21 B 47 C 208 D 435 15 Which statement describes what happens when hydrogen and oxygen are used in a fuel cell? A Electricity is generated directly. B Electricity is used to produce water. C Hydrogen is burned to form steam. D Hydrogen reacts to form a hydrocarbon fuel. 16 The circuit shown is set up and an electric current is pass through the four cells, W, X, Y and Z. In which cells is the intensity of the blue colour of the solution unchanged? A W and Z B Z and Y C X and Z D Y and Z +ve +ve +ve +ve -ve -ve -ve -ve W X Y Z copper(II) sulfate solution platinum electrode copper electrode

8 2023 4E Pure Chemistry Preliminary P1 Hua Yi Secondary School 17 The scheme shows four stages, 1 to 4, in the conversion of solid candlewax, C 30H62, into carbon dioxide and water. 1 C30H62(s) → C30H62(l) 2 C30H62(l) → C30H62(g) 3 C30H62(g) + 45.5 O2(g) → 30CO2(g) + 31H2O(g) 4 30CO2(g) + 31H2O(g) → 30CO2(g) + 31H2O(l) Which stages are exothermic? A 1 and 2 B 1 and 4 C 2 and 3 D 3 and 4 18 The energy profile diagram for the formation of substance R is shown. Q + W → 2R Which of the following statements is correct? 1 The reaction is an exothermic reaction. 2 The ΔH for the reaction is E3 – E1. 3 The activation energy for the reaction is E2 – E1. 4 The activation energy for the reverse reaction is E3 – E2. A 1 only B 4 only C 2 and 3 only D 1, 2, 3 and 4 2R Q+W energy/kJ progress of reaction E1 E2 E3

9 2023 4E Pure Ch