DHS 2026 Prelim P1 QP

This document has 16 pages. Any blank pages are indicated. © DHS 2026 [Turn over Name: Centre/Index Number: Class: DUNMAN HIGH SCHOOL Preliminary Examination Year 6 INSTRUCTIONS • 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 multiple choice answer sheet. • Follow the instructions on the multiple choice answer sheet. • Write in soft pencil. • Write your name, centre number and index number in the boxes at the top of the page. • Do not use correction fluid or tape. • You may use an approved calculator. INFORMATION • The total mark for this paper is 30. • Each correct answer will score one mark. • Any rough working should be done on this question paper. H2 CHEMISTRY Paper 1 Multiple Choice You must answer on the multiple choice answer sheet. You will need: Multiple choice answer sheet Data booklet Soft clean eraser Soft pencil (type B or HB is recommended) 9476/01 25 September 2026 1 hour

2 © DHS 2026 9476/01 1 A helium ion contains two protons, two neutrons and one electron. This helium ion and a proton are passed separately through a uniform electric field. The particles are travelling at the same velocity. Which arrow describes the path of each particle? helium ion proton A 1 2 B 2 1 C 4 3 D 3 4 2 Which statement about the electrons in a ground state oxygen atom is correct? A The occupied orbital of highest energy is spherical. B There are four unpaired electrons present in the n = 2 energy level. C The electrons are distributed across a total of three occupied orbitals. D The number of electrons in s orbitals is equal to the number of electrons in p orbitals. 3 1 + 2 4 ‒

3 © DHS 2026 9476/01 [Turn over 3 Which statements about water and ice are correct? 1 Liquid water contains hydrogen bonds that continually disconnect and reform. 2 On melting, O–H bonds within every water molecule break. 3 In ice, each water molecule forms hydrogen bonds with four neighbouring water molecules in a three-dimensional arrangement. 4 Pure liquid water has negligible electrical conductivity because it contains a negligible concentration of mobile ions. A 1, 3 and 4 only B 1 and 4 only C 2 and 3 only D 1, 2, 3 and 4 4 The electronegativity values of aluminium, phosphorus, sulfur and chlorine are different. Which molecules are polar? 1 AlCl3 2 PCl3 3 PCl5 4 SCl2 A 2, 3 and 4 only B 1 and 3 only C 2 and 4 only D 2 only 5 Mixture R consists of one mole of C3H6 and one mole of C4H6. What is the minimum number of moles of oxygen molecules needed for complete combustion of mixture R? A 6.5 B 7 C 10 D 20

4 © DHS 2026 9476/01 6 Dissociation of Y2(g) into Y(g) occurs within a temperature range. The dissociation begins at –10 C and reaches near completion at 140 C. Both gases behave ideally. Y2(g) ⇌ 2Y(g) Which option shows the correct graph when 1 mol of Y2(g) is placed in a closed system? [Note that the graphs are not drawn to the same scale.] A B C D 0 T / C p / Pa 140 volume kept constant 0 −273 T / C pV / Pa m3 −10 140 0 T / K V / m3 pressure kept constant 413 T / K pV / Pa m3 0 413 263

5 © DHS 2026 9476/01 [Turn over 7 Hydroxylammonium chloride, NH3OHCl, reacts with iron( III) chloride in aqueous solution. In this reaction, one mole of hydroxylammonium ions, NH 3OH+, is oxidised by two moles of Fe3+ ions while Fe3+ ions are reduced to Fe2+. What is the change in the oxidation number of nitrogen in this reaction? A ‒1 to 0 B ‒1 to +1 C +1 to +2 D +1 to +3 8 Element X is in Period 3 of the Periodic Table. After mixing 0.5 mol of the chloride of X with excess water, 2.0 mol of HCl was formed. What is element X? A Mg B Al C Si D P 9 Which property of Group 2 elements (magnesium to barium) or their compounds increases down the group? A The melting points of the elements. B The magnitude of the enthalpy change of hydration of the metal ions. C The thermal decomposition temperature of the carbonates. D The acidity of aqueous solutions of the chlorides. 10 Use of the Data Booklet is relevant to this question. Which statements regarding the Group 17 elements and their hydrides are correct? 1 HI is less volatile than HBr because of the weaker bond between H and I atoms. 2 HF is thermally more stable than HI because of the stronger bond between H and F atoms. 3 Cl2 is a stronger oxidising agent than Br 2 because of the shorter bond length between Cl atoms. A 2 only B 1 and 3 only C 2 and 3 only D 1, 2 and 3

6 © DHS 2026 9476/01 11 Use of the Data Booklet is relevant to this question. The lattice energies of magnesium oxide, magnesium bromide, sodium oxide and sodium bromide are given as options below. Which option corresponds to the lattice energy of magnesium bromide? A –752 kJ mol–1 B –2440 kJ mol–1 C –2564 kJ mol–1 D –3790 kJ mol–1 12 Ammonium chloride dissolves readily in water at room temperature. During the process, the temperature of the solution decreases. Which statements are correct? 1 Dissolution of ammonium chloride is favoured due to the positive entropy change. 2 Dissolution of ammonium chloride in cold water is less spontaneous. 3 The sum of the hydration energies of ammonium ion and chloride ion is less exothermic than the lattice energy of ammonium chloride. A 1, 2 and 3 B 1 and 2 only C 2 and 3 only D 1 only 13 The mechanism for the iodination of propanone in aqueous acid involves the following steps. Which statement is consistent with the mechanism? A Iodine is acting as a catalyst. B The overall order of the reaction is 2. C The rate equation is rate = k[CH3C(OH)CH3+]. D An increase in acid concentration increases the rate constant.

7 © DHS 2026 9476/01 [Turn over 14 The decomposition of hydrogen peroxide in aqueous solution is a first order process. Given that 90% of a solution of 0.10 mol dm–3 hydrogen peroxide remains after 5 minutes at a certain temperature, what will be the remaining concentration, in mol dm –3, of a 1.00 mol dm–3 hydrogen peroxide solution after 5 minutes at the same temperature? A 0.1 B 0.5 C 0.7 D 0.9 15 The following gaseous equilibrium is established in a sealed container at temperature T1 with an equilibrium constant Kp: 2HI(g) ⇌ H2(g) + I2(g) H = +9.6 kJ mol−1 At tim e t, the volume of the container is suddenly halved while the temperature is simultaneously increased to T2. Which statement about the new equilibrium constant, K’p, at temperature T2 is correct? A K’p = Kp because the effects of volume and temperature changes cancel each other out. B K’p = 4Kp because the partial pressures of all species have increased. C K’p > Kp as the increase in temperature favours the endothermic reaction. D K’p < Kp as the reduction in volume favours the side with fewer moles of gas.

8 © DHS 2026 9476/01 16 A fixed amount of