2022 RI Prelim P1 QP

© Raffles Institution 2022 9729/01/S/22 [Turn Over RAFFLES INSTITUTION 2022 YEAR 6 PRELIMINARY EXAMINATION Higher 2 CHEMISTRY 9729/01 Paper 1 Multiple Choice 22 September 2022 1 hour Additional Materials: Multiple Choice Answer Sheet Data Booklet READ THESE INSTRUCTIONS FIRST Do not open this question booklet until you are told to do so. Write in soft pencil. Do not use staples, paper clips, glue or correction fluid. Write your name, class and index number in the spaces provided on the Answer Sheet. 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 the question booklet. The use of an approved scientific calculator is expected, where appropriate. This document consists of 14 printed pages.

© Raffles Institution 2022 9729/01/S/22 [Turn Over 2 1 Use of the Data Booklet is relevant to this question. Which statement is correct? A 2 mol of (NH4)2Fe(SO4)2 has the same number of ions as 4 mol of K2Cr2O7. B 46 g of nitrogen dioxide gas contains the same number of molecules as 14 g of nitrogen gas. C The number of electrons in 1 mol of nitrogen gas is the same as that in 1 mol of carbon monoxide gas. D The number of atoms in a 5 dm 3 sample of oxygen gas is half that of a 10 dm 3 sample of argon gas at the same temperature and pressure. 2 Use of the Data Booklet is relevant to this question. Bronze is an alloy of copper and tin. The following information is obtained for a sample of bronze. mass number 63 65 118 % composition d 88 – d 12 Naturally occurring copper contains only two isotopes, 63Cu and 65Cu. Given the r atio of 63Cu and 65Cu in naturally occurring copper is the same as th at in bronze, what is the value of d? A 22 B 25 C 66 D 75 3 Use of the Data Booklet is relevant to this question. Which statements regarding the ions 30Si4+, 31P3− and 32S2− are correct? 1 They contain the same number of neutrons. 2 They have the same electronic configuration. 3 Their ionic radii increase in the order 30Si4+ < 31P3− < 32S2−. A 1 only B 1 and 2 C 1 and 3 D 2 and 3

© Raffles Institution 2022 9729/01/S/22 [Turn Over 3 4 A beam containing a mixture of three ions, P, Q and R, approaches an electric field with oppositely charged plates at the same velocity. The identities of the three ions could be 11C3+, 15O2+, 7Li2− and 15N4−. Which ion is Q? A 11C3+ B 15O2+ C 7Li2− D 15N4− 5 Use of the Data Booklet is relevant to this question. The first four ionisation energies, IE, of four Period 5 elements, indium, tin, antimony and tellurium are shown in the table below. Which element is indium? first IE / kJ mol−1 second IE / kJ mol−1 third IE / kJ mol−1 fourth IE / kJ mol−1 A 558 1830 2704 5210 B 709 1411 2943 3930 C 834 1594 2440 4260 D 869 1790 2698 3610

© Raffles Institution 2022 9729/01/S/22 [Turn Over 4 6 In which row does G have a smaller overall dipole moment than H? G H A COS CS2 B PCl3 PF3 C IF BrCl D XeF4 PCl5 7 The structures of M and N are as shown. Which statements are correct? 1 M has a lower volatility than N. 2 M and N are constitutional isomers. 3 M and N have the same number of  bonds. A 2 only B 1 and 2 C 1 and 3 D 2 and 3 8 Which compound has the greatest covalent character? A MgO B MgS C CaO D CaS

© Raffles Institution 2022 9729/01/S/22 [Turn Over 5 9 A 1 m 3 vessel containing 20 kPa of helium was connected to a 2 m 3 vessel containing 10 kPa of neon and the gases were allowed to mix at a constant temperature. The two vessels were then cooled, and the temperature of the system decreased. The partial pressures of helium and neon were measured to be U kPa and V kPa respectively. What could be the values of U and V? U V A 10 5 B 7.5 7.5 C 8 4 D 6 6 10 The bar chart shows the melting points of a series of consecutive elements arranged in order of increasing atomic number. The elements sodium to chlorine form part of this series. Which bar represents sodium? 11 Which statement about the element astatine is correct? A Silver astatide is insoluble in aqueous ammonia. B Astatine is a liquid at room temperature and pressure. C The bond energy of hydrogen astatide is larger than that of hydrogen iodide. D Astatine is not a product of the reaction between sodium astatide and bromine.

© Raffles Institution 2022 9729/01/S/22 [Turn Over 6 12 Cyclohexane, C6H12, is prepared industrially by the hydrogenation of benzene as shown in the equation below. C6H6(l) + 3H2(g) ⎯→ C6H12(l) ∆Hr Using the data in the table, what is the standard enthalpy change, ∆Hr, of this reaction? compound standard enthalpy change of combustion / kJ mol−1 C6H6(l) −3268 H2(g) −286 C6H12(l) −3754 A −372 kJ mol−1 B −200 kJ mol−1 C +200 kJ mol−1 D +372 kJ mol−1 13 Which equation represents the standard enthalpy change stated? standard enthalpy change of equation A atomisation of Cl2(g) Cl2(g) ⎯→ 2Cl(g) B combustion of H2S(g) H2S(g) + O2(g) ⎯→ H2(g) + SO2(g) C formation of H2SO4(l) 2H(g) + 4O(g) + S(s) ⎯→ H2SO4(l) D solution of K2SO4(s) K2SO4(s) ⎯→ 2K+(aq) + SO42−(aq) 14 The kinetics of the following reaction is investigated, and the experimental data is given in the table below. 2R + 2S ⎯→ T + U [R] / mol dm−3 [S] / mol dm−3 initial rate / mol dm−3 s−1 0.015 0.010 5.10  10−4 0.030 0.020 4.08  10−3 0.045 0.010 1.53  10−3 What is the numerical value of the rate constant for this reaction? A 0.00294 B 3.40 C 227 D 340

© Raffles Institution 2022 9729/01/S/22 [Turn Over 7 15 Ammonium carbamate, NH2COONH4, undergoes thermal decomposition. NH2COONH4(s) ⇌ 2NH3(g) + CO2(g) H > 0 A vessel containing only NH2COONH4 is heated to 250 oC. The reaction reached equilibrium at time t1. Subsequently both the temperature and volume of the vessel are decreased, and the reaction established a new equilibrium at time t2. Which statements are correct? 1 At t2, PNH3 : PCO2 is 2 : 1. 2 The rate of the forward reaction at t1 is the same as that at t2. 3 The degree of decomposition of NH2COONH4 at t1 is smaller than that at t2. 4 Decreasing the volume of the vessel at constant temperature has no effect on the equilibrium partial pressures of NH3 and CO2. A 2 only B 1 and 3 C 1 and 4 D 2 and 3 16 When a sample of iron( II) sulfate, FeSO 4, is heated to 920 K, reactions 1 and 2 occurred. reaction 1 2FeSO4(s) ⇌ Fe2O3(s) + SO3(g) + SO2(g) K1 reaction 2 2SO3(g) ⇌ 2SO2(g) + O2(g) K2 At equilibrium, the total pressure is 0.836 atm and the partial pressure of oxygen is 0.0275 atm. What is the value of K2 at 920 K? A 0.000147 B 0.0362 C 0.0476 D 0.160 17 The Ka of lactic acid is 1.4  10−4 mol dm−3 at 298 K. A buffer solution contains 1.5 mol dm−3 lactic acid and 0.5 mol dm−3 sodium lactate. Which statement correctly describes the buffer solution? A The pH of the buffer solution is 4.33. B The pH of the buffer solution decreases upon dilution with water. C The buffering capacity of the buffer solution increases upon dilution with water. D The buffer solution has a greater buffering capacity against a base compared to an acid.

© Raffles Institution 2022 9729/01/S/22 [Turn Over 8 18 Some equilibri