RI 2025 Y6 T3 TP Question Paper

1 This document consists of 32 printed pages and 2 blank pages. RAFFLES INSTITUTION 2025 YEAR 6 TERM 3 TIMED PRACTICE Higher 2 CANDIDATE NAME CLASS INDEX NUMBER CHEMISTRY 9729 3 Jul 2025 2 hours 45 minutes Additional Materials: Multiple Choice Answer (OMR) Sheet Data Booklet READ THESE INSTRUCTIONS FIRST Write your name, 6-digit exam index number and civics tutorial group in the spaces provided on the OMR sheet and the cover sheets on pages 1 and 7. Shade your 6-digit exam index number on the OMR sheet. This paper consists of three sections, A, B and C. Section A (15 marks) consists of 15 multiple-choice questions. Answer this section first. The OMR sheet will be collected after the first 30 minutes. 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 OMR sheet. Each correct answer will score one mark. A mark will not be deducted for a wrong answer. Any rough work ing should be done in the question paper. Section B (40 marks) consists of 3 structured questions. Answer all questions in the spaces provided in the question paper. Section C (40 marks) consists of 4 free-response questions. Answer both C1 and C2, and only one of C3 EITHER or C3 OR. Answers to this section are to be written in the spaces provided in the question paper. If additional space is required, you should use the page at the end of the booklet (page 34). The question number must be clearly shown. Write in dark blue or black pen. You may use an HB pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. The use of an approved scientific calculator is expected, where appropriate. The number of marks is given in brackets [ ] at the end of each question or part question.

2 © Raffles Institution 2025 9729/J/25 [Turn Over Section A (15 marks) For each question, there are four possible answers, A, B, C, and D. Choose the one you consider to be correct. 1 Copper has two stable isotopes, 63Cu and 65Cu. Which statement is correct? 2019/Prelim/P1/1 A 63Cu+ ion has fewer unpaired electrons than 65Cu3+ ion. B The electronic configuration of 63Cu+ is [Ar] 3d9 4s1. C 63Cu+ ion has the same number of neutrons as 65Cu3+ ion. D 63Cu2+ ion has fewer protons than 65Cu+ ion. 2 Use of the Data Booklet is relevant to this question. The volume strength of H2O2 is the volume of oxygen in dm3 (measured at s.t.p.) that can be obtained by the decomposition of 1 dm3 of H2O2. H2O2 decomposes to form H2O and O2. 2H2O2 → 2H2O + O2 A solution of H 2O2 has a volume strength of 10. 10 cm3 of this solution is used in a titration with 0.0200 mol dm–3 acidified KMnO4. Given that MnO4– reacts with H2O2 in a 2 : 5 ratio, what volume of KMnO4 is required? 2017/T3CT/2 A 88 cm3 B 167 cm3 C 176 cm3 D 551 cm3 3 The boiling point of butan-1-ol is greater than 2-methylpropan-2-ol. Which statements explain the relative boiling points of these two compounds? 1 The strength of the instantaneous dipole –induced dipole interactions is greater in butan-1-ol than in 2-methylpropan-2-ol. 2 The strength of the hydrogen bonds is greater in butan-1-ol than in 2-methylpropan-2-ol. 3 The extent of hydrogen bonding is greater in butan-1-ol than in 2-methylpropan-2-ol. 2021/T3CT/3 A 1, 2 and 3 B 1 and 3 only C 1 only D 2 only

3 © Raffles Institution 2025 9729/J/25 [Turn Over 4 In which row does G have a smaller overall dipole moment than H? 2022/RI Prelim/1/6 G H A COS CS2 B PCl3 PF3 C IF BrCl D XeF4 PCl5 5 When 30 cm 3 of 1.0 mol dm –3 KOH(aq) is neutralised with an equal volume of 1.0 mol dm–3 HCl(aq), the temperature of the mixture rose by 6.8 °C. What would be the temperature change if 15 cm3 of 2.0 mol dm–3 KOH(aq) is reacted with an equal volume of 2.0 mol dm–3 HCl(aq)? A 3.4 °C B 6.8 °C C 13.6 °C D 27.2 °C 6 Which row gives the correct signs of ∆H and ∆S for the following process? C6H12(s) → C6H12(l) 2019/T3CT/7 ∆H ∆S A + + B + ‒ C ‒ ‒ D ‒ +

4 © Raffles Institution 2025 9729/J/25 [Turn Over 7 Ozone decomposes naturally into oxygen according to the following equation. 2O 3 3O2 The following mechanism has been proposed. O3 O + O2 O + O3 2O2 fast slow step 1 step 2 • • K1 is the equilibrium constant of step 1 and k2 is the rate constant of step 2. Which statements are correct for this reaction? 2021/RI Prelim/1/12 1 The order of reaction with respect to O3 is 2. 2 The overall rate equation is 2 3 21 2 [O ]rate = [O ] kK . 3 Increasing [O2] slows down the reaction. 2021/RI Prelim/1/12 A 1, 2 and 3 B 1 and 3 only C 1 only D 2 only 8 2-Furonitrile has the following structure. Which row correctly describes the bonding and hybridisation in 2-furonitrile? 2017/RI Prelim/1/4 number of π bonds number of sp C atoms number of sp2 C atoms A 3 0 5 B 4 1 4 C 4 0 5 D 2 1 4 9 Which statement about a weak acid is always correct? 2020/T3TP/7 A The conjugate base is a strong base. B Addition of a strong base results in a buffer solution. C A weak acid dissociates to a greater extent with increasing dilution. D The acid dissociation constant, Ka, decreases with increasing temperature. O N

5 © Raffles Institution 2025 9729/J/25 [Turn Over 10 Which solution is the most effective in resisting pH changes when a small amount of acid or base is added? 2021/T3CT/8 A A solution obtained by mixing 15 cm 3 of 1 mol dm –3 CH3CO2Na with 30 cm 3 of 1 mol dm–3 HCl. B A solution obtained by mixing 20 cm 3 of 1 mol dm –3 CH3CO2Na with 10 cm 3 of 1 mol dm–3 HCl. C A solution obtained by mixing 10 cm3 of 1 mol dm–3 CH3CO2H with 20 cm3 of 1 mol dm–3 NaOH. D A solution obtained by mixing 30 cm3 of 1 mol dm–3 CH3CO2H with 15 cm3 of 1 mol dm–3 NaOH. 11 Use of the Data Booklet is relevant to this question. Butane reacts with chlorine to form two constitutional isomers. Cl Cl +Cl2 UV light Which statement is correct? 2017/T3CT/12 modified option D A The reaction is endothermic. B Traces of 3-methylheptane are formed. C The reaction takes place in the presence of aqueous chlorine. D Monochlorination of butane gives a total of two isomers including stereoisomers. 12 When heated with concentrated nitric acid in the presence of a catalyst, chlorobenzene undergoes a reaction to form 4-chloronitrobenzene. Which statement about the above reaction is correct? A FeCl3 is a suitable catalyst for the reaction. B One of the intermediates is Cl O2N H . C The reaction requires a lower temperature compared to benzene. D The reaction involves the electrophilic attack of NO2+ on the benzene ring. Cl2 Cl Cl

6 © Raffles Institution 2025 9729/J/25 [Turn Over 13 An equal amount of each of the following substances was dissolved separately in 1 dm3 of water. The pH of the resultant solutions was measured. CH3COO−Na+, CH3CH2O−Na+, C6H5O−Na+ Which row is correct? 2020/RI Prelim/1/27 lowest pH → highest pH A CH3COO−Na+ CH3CH2O−Na+ C6H5O−Na+ B C6H5O−Na+ CH3CH2O−Na+ CH3COO−Na+ C CH3COO−Na+ C6H5O−Na+ CH3CH2O−Na+ D CH3CH2O−Na+ C6H5O−Na+ CH3COO−Na+ 14 Which statements are correct about the compound below? CONH2 O HOOC CN 2021/RI Prelim/1/23 1 It reacts with H2 in the presence of Pt catalyst to incorporate six hydr