YIJC 2025 Prelim P1 (for exchange) H2 Chem

©YIJC 9729/01/JC2/PE/2025 [Turn over YISHUN INNOVA JUNIOR COLLEGE JC 2 PRELIMINARY EXAMINATION Higher 2 CANDIDATE NAME CG INDEX NO CHEMISTRY Paper 1 Multiple Choice Additional Materials: Multiple Choice Answer Sheet Data Booklet 9729/01 18 September 2025 1 hour READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, glue or correction fluid. Write your name, class 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. This document consists of 17 printed pages and 3 blank pages.

©YIJC 9729/01/JC2/PE/2025 2 1 Three different charged particles are fired with equal velocity into an electric field. The diagram below shows how each particle is deflected. Which row gives the correct identities of D, E and F? D E F A 14N+ 28Si2– 14C2– B 14N– 28Si2+ 14C2+ C 16O2+ 16O2– 28Si– D 16O2– 16O2+ 28Si+ 2 Use of the Data Booklet is relevant to this question. The graph shows the first thirteen successive ionisation energies for element G. What can be deduced about element G from the graph? A It is aluminium. B It is a d-block element. C It is in Period 3 of the Periodic Table. D The outermost electronic configuration is ns2. ionisation energy number of electrons removed + – D E F

3 ©YIJC 9729/01/JC2/PE/2025 [Turn over 3 Which statement describes a phenomenon caused by intermolecular hydrogen bonding? A The boiling point of an alcohol increases with increasing carbon chain length. B Hydrochloric acid forms H3O+ when dissolved in water. C CH3CHO has a higher boiling point than CH3CH2CH3. D Ice has a lower density than water at 0 °C. 4 In certain microwave ovens, the wave energy produced is absorbed by polar molecules. Which molecules would absorb microwave energy? 1 CH3CH2OH 2 AlCl3 3 CO2 4 CH3F A 1 and 2 only B 1 and 4 only C 2 and 3 only D 3 and 4 only 5 Element J is in Period 3 of the Periodic Table. The four statements below describe the properties of element J or its compounds. Three statements are correct descriptions. One of the statements is not correct because it does not fit with the other three. Which statement is not correct? A Element J is a solid at room temperature which conducts electricity. B The oxide of element J dissolves in water to give an alkaline solution. C Element J forms a trichloride, JCl3, which reacts with water to give an acidic solution. D The oxide of element J reacts with both hydrochloric acid and sodium hydroxide solution.

©YIJC 9729/01/JC2/PE/2025 4 6 The table below shows the observations when a hot wire is inserted into separate samples of hydrogen chloride, hydrogen bromide and hydrogen iodide gas. hydrogen halide observation HCl no observable change HBr reddish brown vapour only when wire is very hot HI purple vapour immediately forms Which statements explain the observations? 1 Valence orbital size increases from Cl to Br to I. 2 Bond strength decreases from H–Cl to H–Br to H–I. 3 The electron cloud size of the hydrogen halide increases from HCl to HBr to HI. A 1, 2, and 3 B 1 and 2 only C 2 and 3 only D 1 only 7 Which statements are correct? 1 The relative isotopic mass is the ratio of the mass of an atom of an isotope compared with 1 12 of the mass of a carbon-12 atom. 2 The relative molecular mass is the ratio of the average mass of an atom in a molecule compared with 1 12 of the mass of a carbon-12 atom. 3 One mole of a compound is the amount that contains the same number of atoms as there are atoms in 12.00 g of carbon-12. A 1, 2, and 3 B 1 and 2 only C 2 and 3 only D 1 only

5 ©YIJC 9729/01/JC2/PE/2025 [Turn over 8 Use of the Data Booklet is relevant to this question. Upon heating to 573 K, ammonium nitrate, NH4NO3, decomposes into dinitrogen monoxide and water vapour. 0.2 g of NH4NO3 is heated to 573 K and then cooled. At room temperature and pressure, the amount of gas is 0.00208 mol. What percentage of NH4NO3 has decomposed? A 27.8% B 29.4% C 83.3% D 88.1% 9 Use of the Data Booklet is relevant to this question. The experimental set-up below has a heat transfer efficiency of 90%. In an experiment, 1.00 g of propan-1-ol (Mr = 60.0) was burnt under a vessel containing 200 g of water. It was found that the temperature of the water rose by 39.5 °C. Which value for the enthalpy change of combustion of propan-1-ol is given by these results? A −1780 B −2200 C −15700 D −17400 thermometer lamp containing propan-1-ol vessel containing of water

©YIJC 9729/01/JC2/PE/2025 6 10 The nitride ion, N3–, is usually found in compounds used for hard, heat -resistant materials, while the azide ion, N3–, is found in compounds that are used in airbags. Which compound has the least negative value for lattice energy? A magnesium azide B magnesium nitride C sodium azide D sodium nitride 11 The melting point of ammonia is 195 K and the boiling point of ammonia is 240 K. The graph below shows how the entropy of NH3 changes between 0 K and 300 K. Which statements explain the shape of the graph? 1 Between 0 K and 195 K, entropy is low as the NH3 molecules are held in their fixed positions in the solid state. 2 Between 195 K and 240 K, there is an increase in the number of ways to distribute energy among NH3 molecules. 3 At 240 K, there is an increase in the number of NH 3 molecules and hence number of ways to arrange NH3 molecules. A 1 and 2 only B 1 and 3 only C 2 and 3 only D 1, 2, and 3 0 240 temperature / K entropy 300 195

7 ©YIJC 9729/01/JC2/PE/2025 [Turn over 12 The hydrolysis of sucrose to glucose and fructose is catalysed by acid. The reaction is first order with respect to sucrose and first order with respect to acid. Which row correctly describes the effect on rate of reaction and half -life of sucrose when [acid] is doubled? rate of reaction half-life of sucrose A remains the same remains the same B remains the same halves C doubles remains the same D doubles halves 13 The diagram shows the Boltzmann distribution for a sample of a reacting gas at a constant temperature. The activation energy, EA, for the uncatalysed reaction is marked. A catalyst is added to the sample of gas under constant temperature. Which point could show the intercept of the Boltzmann distribution curve with the value of the activation energy of the reaction? number of particles energy EA B A D C

©YIJC 9729/01/JC2/PE/2025 8 14 Consider the following three equilibria and their equilibrium constants, K1, K2 and K3. equilibrium 1 CO2 + H2O ⇌ HCO3− + H+ K1 equilibrium 2 HCO3− ⇌ CO32− + H+ K2 equilibrium 3 CO2 + H2O + CO32− ⇌ 2HCO3− K3 What is the correct expression for K3? A K1 × K2 B K2 / K1 C K1 / K2 D 1 / (K1 × K2) 15 In this question, you should assume that all gases behave ideally. Hydrogen and iodine react reversibly in the following reaction. The system is allowed to reach dynamic equilibrium. H2(g) + I2(g) ⇌ 2HI(g) ∆H = –9.5 kJ mol–1 Which row correctly describes how the equilibrium position and Kp are affected by an increase in temperature? equilibrium po