2024 Prelims DHS H2 Chem P1 (QP)

© DHS 2024 9729/01 [Turn over Name: Centre/Index Number: Class: DUNMAN HIGH SCHOOL Preliminary Examination Year 6 H2 CHEMISTRY Paper 1 Multiple Choice Additional Materials: Multiple Choice Answer Sheet Data Booklet 9729/01 20 September 2024 1 hour READ THESE INSTRUCTIONS FIRST Write your centre number, index number, name and class at the top of this page. Write in soft pencil. Do not use staples, paper clips, glue or correction fluid. 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 16 printed pages.

2 © DHS 2024 9729/01 1 Use of the Data Booklet is relevant to this question. Which transition metal ions have the same number of unpaired electrons as a phosphorus atom in its ground state? 1 Ti2+ 2 V2+ 3 Cr3+ A 1 and 2 only B 2 and 3 only C 1 and 3 only D 1, 2 and 3 2 Use of the Data Booklet is relevant to this question. What is the order of decreasing enthalpy change for the reactions shown? Si+(g) → Si2+(g) + e− H1 Al+(g) → Al2+(g) + e− H2 Si(g) → Si2+(g) + 2e− H3 A H1 > H2 > H3 B H2 > H3 > H1 C H3 > H1 > H2 D H3 > H2 > H1

3 © DHS 2024 9729/01 [Turn over 3 Analysis of a mixture of sulfur-containing gases shows that hydrogen sulfide, H 2S, and carbon disulfide, CS2, are present in a 2 : 1 mole ratio. The mixture is burned in excess oxygen. Which row describes: • the SO2 : CO2 mole ratio in the mixture obtained after complete combustion, • the relative deviation from ideal behaviour of the gases, CO2 and CS2? SO2 : CO2 mole ratio relative deviation A 3 : 1 CS2 deviates more than CO2 B 4 : 1 CS2 deviates more than CO2 C 3 : 1 CO2 deviates more than CS2 D 4 : 1 CO2 deviates more than CS2 4 The table shows the melting points of two ionic compounds. compound melting point / °C CaO 2613 NaF 993 Which statement helps to explain the relative melting points of CaO and NaF? A Ca2+ has a larger ionic radius than Na+. B Ca2+ has a higher charge density than Na+. C The sum of ionic radii is larger for CaO than NaF. D The ionic charges are larger in magnitude for CaO than NaF. 5 How many of the molecules listed are polar and have the same shape? • NCl3 • HCN • BeCl2 • SOCl2 A none B 2 C 3 D 4

4 © DHS 2024 9729/01 6 A student carries out an investigation using a mixture of Period 3 oxides, X and Y. All experiments are carried out at room temperature. mixture of solids X and Y CuSO4(s) pale blue precipitate shake with an excess of dilute NaOH(aq) colourless solution + solid Y colourless solution ? shake with an excess of water shake with an excess of dilute HCl(aq) experiment 1 Which observation would the student make of the result of experiment 1? A Colourless solution only B Colourless solution + solid X C Colourless solution + solid Y D Mixture of solids X and Y 7 Which statement about the behaviour of Group 2 elements from magnesium to barium is correct? A The polarising power of the cations increases. B The oxidising power of the elements increases. C The covalent character of the metal chlorides increases. D The thermal stability of the metal carbonates increases.

5 © DHS 2024 9729/01 [Turn over 8 Use of the Data Booklet is relevant to this question. An excess of aqueous chlorine was added to a sample of aqueous potassium bromide in a test-tube. An equal volume of aqueous silver nitrate was then added to the resulting solution. Which row of observations would be made? on adding chlorine on adding silver nitrate A colourless solution remains cream precipitate formed B colourless solution turns orange cream precipitate formed C colourless solution turns orange white precipitate formed D colourless solution turns pale yellow white precipitate formed 9 Use of the Data Booklet is relevant to this question. The following reactions at 298 K, form an energy cycle. 2P(s) + 5Cl2(g) 2P(g) + 10Cl(g)2P(g) + 5Cl2(g) 2PCl5(s) H1 H2 H3 H4 Which descriptions of the enthalpy changes are correct? 1 H1 + H2 > +1220 kJ mol−1 2 H3 = 10 × P−Cl bond energy 3 H4 = 2 × Hformation of PCl5(s) A 1 and 2 only B 1 and 3 only C 2 and 3 only D 1, 2 and 3

6 © DHS 2024 9729/01 10 For the reaction, N2(g) + 3H2(g) ⇌ 2NH3(g), H = −92 kJ mol−1. Which statement about the forward reaction is correct? A It is spontaneous only at low temperature. B It is spontaneous only at high temperature. C It is not spontaneous at any temperature. D It is spontaneous at all temperatures. 11 0.02 mol of an iodine oxide reacts with 0.2 mol of acidified potassium iodide to give 0.12 mol of iodine, I2. What is the oxidation number of iodine in the oxide? A +1 B +3 C +5 D +7 12 An excess of H 2 gas is reacted with Cl2 gas in a 1 dm3 vessel at constant temperature. The reaction is catalysed by UV light and is found to be zero order with respect to Cl2. Which diagram represents the variation of partial pressure of Cl2 gas, px, with time? A B C D 0 px time 0 px time 0 px time 0 px time

7 © DHS 2024 9729/01 [Turn over 13 The kinetics of the following reaction is studied by finding the time taken for a coloured reactant, A, to decolourise. The reaction is catalysed by Y. A + B C + D The following results are obtained: Which statements about this reaction are correct? experiment number volume of A added / cm3 volume of B added / cm3 volume of Y added / cm3 volume of H2O added / cm3 time taken / s 1 10 20 10 10 20 2 10 10 10 20 40 3 10 20 5 15 40 4 5 20 10 15 10 5 2.5 20 10 17.5 ? 1 Colorimetry can be used to monitor the kinetics of the reaction. 2 The rate equation is rate = k[B][Y]. 3 The time taken for experiment 5 is 5 s. A 1, 2 and 3 B 1 and 2 only C 1 only D 2 and 3 only Y

8 © DHS 2024 9729/01 time/ min total pressure of system/ Pa X 14 E and F are reacted in a closed vessel to form G as shown. E(g) + F(g) G(g) At time X min, 1 mol of inert gas P is added at constant volume. Which of the following graphs represents the variation of total pressure of the system with time? A B C D time / min total pressure of system/ Pa X time / min total pressure of system/ Pa X total pressure of system/ Pa time / min X

9 © DHS 2024 9729/01 [Turn over 15 A metal hydroxide dissolves partially in water as shown: M(OH)2(s) + aq ⇌ M2+(aq) + 2OH–(aq) H > 0 Which statements are correct as temperature increases? 1 Equilibrium is reached at a faster rate. 2 pH of the solution increases. 3 Ksp of M(OH)2 increases. A 1, 2 and 3 B 1 and 2 only C 2 and 3 only D 1 and 3 only 16 Which of the following pairs can be used to prepare a buffer of approximately pH 6 that has maximum buffer capacity? A NH4+ and NH3 Kb of NH3 = 1.78 × 10−5 mol dm−3 B H2CO3 and HCO3− Kb of HCO3− = 2.38 × 10−8 mol dm−3 C H3PO4 and H2PO4− Kb of H2PO4− = 1.33 × 10−12 mol dm−3 D CH3COOH and CH3COO− Kb of CH3COO− = 5.71 × 10−12 mol dm−3

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