2025 DHS H2 Chem Prelim Paper 1 QP

© DHS 2025 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 25 September 2025 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 12 printed pages.

2 © DHS 2025 9729/01 1 In two separate experiments, a beam of alpha particles ( 4He2+) and a beam of charged particles X were fired with equal velocities into an electric field. + _ beam of particles The angle of deflection of the charged particles, 4He2+ and X, was found to be + 1 and +6 respectively. Which statement is correct? A X is negatively charged. B X travels in a straight path towards one of the charged plates. C X could be a 12C+ ion. D None of the above. 2 Use of the Data Booklet is relevant to this question. W is an isotope of an element. An isotope of strontium has a nucleon number of 84 and the same number of neutrons in the nucleus as the isotope W. The species Sr2+ and W contain the same number of electrons. What is the nucleon number of W and how many orbitals are occupied in its valence shell? W number of orbitals occupied in valence shell A 80 3 B 82 4 C 82 3 D 84 4

3 © DHS 2025 9729/01 [Turn over 3 The molecules CO2, CS2 and COS have the same shape. Which statements are correct? 1 The molecules all contain polar covalent bonds. 2 The molecules each contain two sigma and two pi bonds. 3 Only COS has permanent dipole–permanent dipole interactions. 4 COS has stronger instantaneous dipole–induced dipole interactions than CS2. A 1, 2 and 3 only B 2 and 4 only C 2 and 3 only D 1 and 4 only 4 Which row correctly describes the structure and bonding present in the solid lattice of the given substance? substance structure bonding A ice giant molecular covalent and hydrogen bonding B iodine simple molecular covalent bonding and permanent dipoles C sodium nitrate giant ionic ionic and covalent bonding D manganese giant metallic ionic bonding 5 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. 60 cm3 of the gaseous mixture is burned in excess oxygen. The resulting gases are bubbled through aqueous sodium hydroxide. All volumes are measured under the same temperature and pressure. Which row correctly describes • the SO2 : CO2 mole ratio in the gaseous mixture obtained after complete combustion and • the reduction in volume of the gaseous mixture when bubbled through NaOH(aq)? SO2 : CO2 mole ratio reduction in volume A 3 : 1 80 cm3 B 4 : 1 80 cm3 C 3 : 1 100 cm3 D 4 : 1 100 cm3

4 © DHS 2025 9729/01 6 Which graph does not represent the behaviour of a fixed mass of an ideal gas? A B 0 0 density p at constant T 0 0 V T / K at constant p C D 0 0 pV/T p 0 0 p p/T at constant V 7 0.00200 mol of nitrate ions was reduced by 30.0 cm3 of 0.200 mol dm–3 iron(II) sulfate to form a brown iron(III) complex. What is a possible identity of the nitrogen–containing product? A N2 B NO C NO2– D NO2 8 K, L and M are elements with atomic numbers between 11 and 18. They have the following properties compared to other elements in Period 3. • K has the largest ionic radii. • L has the highest melting point. • M has the second highest electrical conductivity at room temperature. Arrange the elements in order of increasing atomic number. A K, L, M B L, M, K C K, M, L D M, L, K

5 © DHS 2025 9729/01 [Turn over 9 Which trends down a Group in the Periodic Table are correct? 1 Electronegativity of Group 1 elements decreases 2 Reducing power of Group 2 elements increases 3 Volatility of Group 17 elements increases A 1 and 2 only B 2 and 3 only C 1 and 3 only D 1, 2 and 3 10 The standard entropy change of formation, Sf, of a substance is similarly defined as the standard enthalpy change of formation, Hf. Which Period 3 oxide has the most negative Sf? A sodium oxide B magnesium oxide C silicon dioxide D sulfur dioxide 11 Use of the Data Booklet is relevant to this question. Which solid has the most exothermic lattice energy? [Assume the lattice structure of the following compounds are identical.] A TiF3 B FeF3 C TiO D FeO 12 0.70 g of fuel undergoes complete combustion to heat up 500 cm 3 of water by 7.5 C. The system is known to be 70% efficient. What is the energy released per gram, in kJ g–1, of the fuel burnt? A 15.7 B 22.4 C 32.0 D 1196 13 The rate of removal of aspirin, a pain–killer drug, from the body follows a first–order reaction. It takes 6.0 hours for 87.5% of aspirin to be removed from the body. What is the value of the rate constant for this reaction? A 0.462 h–1 B 0.347 h–1 C 0.116 h–1 D 0.0385 h–1

6 © DHS 2025 9729/01 14 Consider the following reaction: 3P + Q → P3Q The proposed mechanism for the reaction involves the following steps: 2P ⇌ P2 fast P2 + Q → P2Q slow P2Q + P → P3Q fast Based on the given information, what is the rate equation for the reaction? A rate = k[P]2[Q] B rate = k[P2][Q] C rate = k[P]2 D rate = k[P]3[Q] 15 Which statement is correct for the equilibrium below? N2(g) + 3H2(g) ⇌ 2NH3(g) H < 0 change effect on position of equilibrium effect on Kc A addition of catalyst shifts right no change B addition of argon gas at constant volume shifts left decreases C decrease in temperature shifts right increases D decrease in volume of vessel shifts left no change

7 © DHS 2025 9729/01 [Turn over 16 Solutions E, F, G and H contain HCl(aq), CH3COOH(aq), NaOH(aq) and NH4Cl(aq) but not necessarily in the same order. The concentration and pH for each solution are shown below. solution concentration / mol dm–3 pH E 1.0 4.0 F 1.0 5.8 G 0.01 12.0 H 0.01 2.0 Which statements are correct? 1 E contains a weak acid while H contains a strong acid. 2 Mixing 10 cm3 of E and 500 cm3 of G produces a buffer solution. 3 Mixing 10 cm3 of F and 50 cm3 of H produces a buffer solution A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only 17 At a body temperature of 37 ºC, Kw has a value of 2.4  10–14. What is the concentration of OH– if the pH of blood is 7.4 under these conditions? A 3.98  10–8 mol dm–3 B 6.03  10–7 mol dm–3 C 2.51  10–7 mol dm–3 D 7.00  10–7 mol dm–3 18 The solubilities of BaSO4 and PbSO4 are x and y mol dm–3 respectively at 298 K. A solution saturated with both BaSO 4 and PbSO4 was prepared by dissolving BaSO 4(s) and PbSO4(s) in water at 298 K. Which statements about the saturated solution are correct? 1 [SO42–] = (x + y) mol dm–3 2 [Ba2+] < x mol dm–3 3 [SO42–] = [Ba2+] + [Pb2+] A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only

8 © DHS 2025 9729/01 19 A mixture of propyne and propadiene is produced as side products during the cracking of propane. Propyne exists in equil