2024 Prelims ACJC H2 Chem P1 (QP)

This document consists of 15 printed pages. Anglo-Chinese Junior College JC2 Preliminary Examination Higher 2 CHEMISTRY Paper 1 Multiple Choice Additional Materials: Multiple Choice Answer Sheet Data Booklet 9729/01 9 September 2024 1 hour READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, glue or correction fluid. Write your name, Centre number and index number on the Answer Sheet in the spaces provided unless this has been done for you. There are thirty 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. The use of an approved scientific calculator is expected, where appropriate.

2 © ACJC2024 9729/Preliminary Examinations/2024 [Turn over 2 0.01 mol of an unknown ion G2+ required 17.25 cm 3 of 0.23 mol dm −3 acidified KMnO4 to reach the end-point. What is the final oxidation state of element G? A +3 B +4 C +5 D +6 3 Which ion will be deflected the most in an applied electric field? A 79Br+ B 81Br2+ C 81Br+ D 82Br2+ 1 The incomplete combustion of a gaseous hydrocarbon produced 80 cm 3 of carbon dioxide, 40 cm3 of carbon monoxide and 160 cm3 of water vapour. What volume of oxygen was used for combustion of the hydrocarbon? A 40 cm3 B 80 cm3 C 160 cm3 D 180 cm3 4 An unstable ion has • a nucleon number of 219, • 51 more neutrons than electrons, • an atomic number of 84, 85, 86, or 87, What could this ion be? A Po2+ B At3+ C Rn4+ D Fr5+

3 © ACJC2024 9729/Preliminary Examinations/2024 [Turn over pV p N2 B A C D 5 Which species contains two 𝜋 bonds? 1 BF3NH3 2 CH2CHCH2CH3 3 CH2CHCHO 4 HCO2CH2COCH3 A 1 and 4 only B 2 and 3 only C 2 and 4 only D 3 and 4 only 6 What is the strongest intermolecular force in ethanal, ethylamine and decan-1-ol? ethanal ethylamine decan-1-ol A hydrogen bonds hydrogen bonds induced dipoles B permanent dipoles hydrogen bonds induced dipoles C permanent dipoles permanent dipoles hydrogen bonds D hydrogen bonds permanent dipoles hydrogen bonds 7 The volumes and pressures of equal masses of two gases, N 2 and NH3, are separately investigated at constant temperature. The results are plotted on a graph of pV against p. Both gases behave as ideal gases under the conditions chosen. The result for N2 is given. Which plot shows the result for NH3?

4 © ACJC2024 9729/Preliminary Examinations/2024 [Turn over 8 What can be added to a mixture of MgO and Al2O3 to separate them by filtration? 1 water 2 HCl(aq) 3 NaOH(aq) A 1, 2 and 3 B 1 and 2 only C 2 and 3 only D 3 only 9 The following table shows the results of two experiments involving Group 17 halides, X− and Y−. experiment deduction halogen Z2 added to X− X2 formed halogen Z2 added to Y− Y2 not formed Which row shows the halogens in decreasing order of oxidising strengths? A Y2, Z2, X2 B Y2, X2, Z2 C X2, Z2, Y2 D X2, Y2, Z2

5 © ACJC2024 9729/Preliminary Examinations/2024 [Turn over 10 An Ellingham diagram is a plot of ∆ G versus temperature and it can be used to show the stability of compounds at various temperatures. The following Ellingham diagram is for reactions 1 and 2. reaction 1 W + X → Y reaction 2 2W + X → 2Z Which statement is incorrect? A Reaction 1 is favoured at lower temperatures. B The entropy change of reaction 2 is negative. C The enthalpy change of reaction 2 is −220 kJ mol−1. D At 983 K, G of the reaction 2Z → W + Y is zero. -600 -500 -400 -300 -200 -100 0 0 500 1000 1500 2000 T / K ∆Go / kJ mol−1 983 −220 reaction 1 reaction 2

6 © ACJC2024 9729/Preliminary Examinations/2024 [Turn over 11 When an instant cold pack is used, a vigorous reaction occurs, and the temperature falls from 25 °C to 5 °C. What are the correct signs of ∆G and ∆S for this reaction? ∆G ∆S A + + B + − C − + D − − 12 The Dushman reaction is represented by the following equation. IO3–(aq) + 5I–(aq) + 6H+(aq) → 3I2(aq) + 3H2O(l) The rate equation for this reaction is as follows. rate = k[IO3–][I–]2[H+]2 When the concentration of each reactant is a mol dm-3, the initial rate was found to be y mol dm–3 s–1. What will be the initial rate of the reaction if [IO3–] is 2a, [I–] is 1 2 a, and [H+] is 4a? A 2y B 4y C 8y D 16y 13 3.0 mol of Q, 1.5 mol of R and 0.2 mol of S are mixed in a 2.0 dm3 flask and allowed to reach equilibrium. 4Q(g) + R(g) S(g) The equilibrium mixture contained 0.8 mol of S. What is the equilibrium concentration of Q in the flask? A 2.4 mol dm−3 B 1.2 mol dm−3 C 0.6 mol dm−3 D 0.3 mol dm−3

7 © ACJC2024 9729/Preliminary Examinations/2024 [Turn over 14 Water dissociates according to the equation: H2O(l) H+(aq) + OH−(aq) The pH of water at different temperatures are shown below. temperature / K pH 298 7.0 333 6.5 Which statements are true? 1 The dissociation of water is endothermic. 2 The pKa of water increases when the temperature increases. 3 Water becomes more acidic when the temperature increases. A 1 only B 1 and 2 only C 2 and 3 only D 1, 2 and 3 15 The table below describes some indicators. indicator colour in acid colour in alkali pKa range of pH for colour change methyl orange red yellow 3.7 3.2 − 4.4 thymol blue yellow blue 8.9 8.0 − 9.6 For the titration of NaOH(aq) against HCOOH(aq), w hich row shows the most suitable indicator and the corresponding colour change? indicator colour change A methyl orange red to orange B methyl orange yellow to orange C thymol blue yellow to green D thymol blue blue to green

8 © ACJC2024 9729/Preliminary Examinations/2024 [Turn over 16 Levocabastine is an antihistamine used in the treatment of sore eyes. Which functional group is not present in Levocabastine? A alcohol B amine C aryl halide D nitrile 17 1,2-epoxycyclopentane can be converted to cyclopent-2-en-1-ol in a single reaction. 1,2-epoxycyclopentane cyclopent-2-en-1-ol Which statement about the reaction is correct? A 1,2-epoxycyclopentane rotates plane-polarised light. B A reducing agent is used for this reaction. C Cyclopent-2-en-1-ol is more volatile than the 1,2-epoxycyclopentane. D An isomerisation reaction has occurred.

9 © ACJC2024 9729/Preliminary Examinations/2024 [Turn over 18 Both benzene and propene react with bromine. Which statement best explains the difference in the reactivity between these compounds? A Benzene is a planar molecule which allows ease of attack by bromine whereas propene is a non-planar molecule. B The carbocation intermediate produced in the reaction of benzene with bromine is stabilised by resonance. C The sideway overlap of p orbitals in benzene means the C−C bonds alternate between long, single bonds and short, double