2024 Prelims NYJC H2 Chem P1 (QP)

[Turn Over This document consists of 19 printed pages. NANYANG JUNIOR COLLEGE JC 2 Preliminary Examination Higher 2 CHEMISTRY 9729/01 Paper 1 Multiple Choice 16 Sep 2024 1 hour Additional Materials: Multiple Choice Answer Sheet Data Booklet READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, glue or correction fluid. Write your name, CT and NRIC / FIN on the Answer Sheet in the spaces provided. There are thirty questions in 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. H

2 H2 Chemistry 9729/01 NYJC J2/2024 PX 1 Use of the Data Booklet is relevant to this question. Group 1, 2 and 3 metals form cations with +1, +2 and +3 oxidation states respectively. Calcium and V are adjacent elements in Group 2 of the Periodic Table. V and W are adjacent elements in the same period of the Periodic Table. The table shows the angle of deflection of cations of these elements in an electric field. element calcium V W angle of deflection +12° +5.5° +8.1° What is the proton number of W? A 11 B 13 C 37 D 39 2 Use of the Data Booklet is relevant to this question. The successive ionisation energies, in kJ mol–1, of elements G and H are given below. G 580 1820 2740 11600 14800 18400 23300 H 940 2050 2970 4140 6590 7880 14900 Which statements about elements G and H can be deduced from the data? 1 There is inter-electron repulsion in only one valence p orbital of H. 2 The 3rd ionisation energy of H is greater than the 3rd ionisation energy of G because nuclear charge of H is larger. 3 The compound formed by G and H is Al2Te3. A 1, 2 and 3 B 1 and 2 C 1 and 3 D 3 3 In which of the following pairs, is the bond angle in the first molecule larger than in the second? A NO3−, BeCl2 B BrO3−, PCl4+ C AsF6−, XeF4 D SO2, SO42−

3 H2 Chemistry 9729/01 NYJC J2/2024 PX [Turn Over 4 What is the trend in bond energy and in bond length of the carbon to hydrogen bond from C2H2 to C2H4 to C2H6? bond length bond energy A increase decrease B increase increase C decrease increase D decrease decrease 5 When hexanol is mixed with water, two distinct layers is observed. Which two intermolecular forces of attraction are best used to explain this observation? 1 instantaneous dipole - induced dipole interactions between hexanol molecules 2 hydrogen bonding between hexanol molecules 3 hydrogen bonding between water molecules 4 instantaneous dipole - induced dipole interactions between hexanol and water molecules A 1 and 3 B 1 and 4 C 2 and 3 D 3 and 4 OH OH OH OH OH OH OH OH OH H O H H O H HO H HO H H O H H O H H OH H O H H O H H OH H O H HO H HO H H O H H OH HO H HO H H O H H OH H OH H O H

4 H2 Chemistry 9729/01 NYJC J2/2024 PX 6 Which oxide will not dissolve in dilute NaOH(aq) at room temperature? A Na2O B MgO C Al2O3 D P4O10 7 Which statements explain the difference in thermal decomposition temperature between MgCO3(s) and BaCO3(s)? 1 Mg2+ has a smaller ionic radius than Ba2+. 2 CO32− electron cloud is less polarised in MgCO3. 3 C−O bond is stronger in MgCO3. A 1, 2 and 3 B 1 and 2 only C 2 and 3 only D 1 only 8 2 cm3 solution of Cl2(aq) is added to 2 cm3 solution of I−(aq). The resulting mixture is added to 4 cm3 of octane in a boiling tube. The contents of the boiling tube was shaken and left to stand to reach equilibrium. Which statement is correct? A Brown colour is seen in the octane layer. B Brown colour is seen in the aqueous layer. C The attraction of chlorine nucleus to an incoming electron is stronger than the attraction of iodine nucleus to an incoming electron, hence chlorine is a stronger oxidising agent than iodine. D The attraction of iodide nucleus for its valence electrons is weaker than the attraction of chloride nucleus to its valence electrons, hence iodide is a weaker reducing agent than chloride.

5 H2 Chemistry 9729/01 NYJC J2/2024 PX [Turn Over 9 Use of the Data Booklet is relevant to this question. A Jones reductor is a column containing zinc amalgam. When a solution containing a metal ion is passed through a Jones reductor, zinc metal is oxidised and the metal ion is reduced. When 40.0 cm 3 of an acidified solution of 0.200 mol dm −3 ReO4−(aq) is added to a Jones reductor, 2.09 g of Zn metal was lost from the column. What is the final oxidation state of Re in this reaction? A −1 B 0 C +2 D +3 10 Which of the following shows a correct enthalpy change? A ∆Hneut Ɵ 2NaOH(aq) + H2SO4(aq) → Na2SO4(aq) + 2H2O(l) B ∆Hf Ɵ 2Na(s) + 1 2 O2(g) → Na2O(s) C ∆Hhyd Ɵ NaCl(s) → Na+(aq) + Cl−(aq) D LE NaOH(s) → Na+(g) + OH−(g) 11 The ∆Hf ⬚ for steam is shown. H2(g) + ½ O2(g) → H2O(g) ∆Hf ⬚ = −241.5 kJ mol−1 Which statement is correct? A The reaction is always spontaneous. B The reaction is more spontaneous at lower temperatures. C The reaction is more spontaneous at higher temperatures. D The reaction is never spontaneous.

6 H2 Chemistry 9729/01 NYJC J2/2024 PX 12 222Rn is a radioactive isotope found naturally in soil. It can build up in indoor air from soil under foundations of buildings. 222Rn has a half-life of 3.82 days. Radiation in air is measured in units of picocurie (pCi) per dm 3 of air. Outdoor air generally contains 0.4 pCi dm −3 of 222Rn. The air in a sealed disused building contains 15 pCi dm −3 of 222Rn. How many days does it take for 222Rn in the building to decompose to a safe level? A 0.04 B 0.15 C 5.23 D 19.97 13 The Haber process is used in the industry for the synthesis of ammonia from nitrogen and hydrogen gas. N2(g) + 3H2(g) 2NH3(g) ∆H < 0 Which statements about the operating conditions of the Haber process are correct? 1 Perforated Pt mesh with a large surface area is used to ensure the rate of the forward reaction is greater than the rate of the backward reaction. 2 A temperature below 500 K is not used as the rate of reaction will be too slow. 3 A pressure of 2.03  107 Pa is used to reduce the total number of gas particles in the reaction chamber. A 1, 2 and 3 B 1 and 2 C 2 and 3 D 3 only

7 H2 Chemistry 9729/01 NYJC J2/2024 PX [Turn Over 14 Malonic acid has the structure HO2CCH2CO2H. A 25.0 cm3 solution contains a mixture of malonic acid and its conjugate base HO2CCH2CO2−. It is titrated against a 0.100 mol dm−3 NaOH(aq) to obtain the graph below. Given: HO2CCH2CO2H pKa = 2.85 HO2CCH2CO2− pKa = 5.70 What is the initial pH of the solution? A 2.12 B 2.70 C 2.85 D 3.00 15 Some metal hydroxides and carbonates are separately dissolved in distilled water to produce saturated solutions. Given Kb of CO32− is 2.1  10−4 mol dm−3, which compound will give a solution with the highest pH? magnitude of Ksp A MgCO3 3.5  10−8 B MnCO3 1.8  10−11 C Ni(OH)2 2.0  10−15 D Sc(OH)3 8.0  10−31 pH 10 22 34 VNaOH/cm3 5.70

8 H2 Chemistry 9729/01 NYJC J2/2024 PX 16 Lenacapavir is an anti-retroviral medication used for the treatment of HIV. O N N N H NN N Cl F F F N H S O O FFH H F F F S O O F F Lenacapavir Given that •