2024 DHS Y6 H1 Prelim Paper 1 QP

© DHS 2024 8873/01 [Turn over Name: Centre/Index Number: Class: DUNMAN HIGH SCHOOL Preliminary Examination Year 6 H1 CHEMISTRY Paper 1 Multiple Choice Additional Materials: Multiple Choice Answer Sheet Data Booklet 8873/01 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 15 printed pages and 1 blank page.

2 © DHS 2024 8873/01 1 Which diagram shows the correct arrangement of valence electrons of a S+ ion in the ground state? A 3s 3p 3s 3p 3s 3p 3s 3p B 3s 3p 3s 3p 3s 3p 3s 3p C 3s 3p 3s 3p 3s 3p 3s 3p D 3s 3p 3s 3p 3s 3p 3s 3p 2 The mineral pyrite only contains isotopes of sulfur and iron. A sample of pyrite was analysed and four different types of atom were identified: V, W, X and Y. atom relative mass relative % abundance V 32 63.8 W 34 2.8 X 54 31.4 Y 56 2.0 Which statements are correct? 1 Y2+ is isoelectronic with X. 2 Y has 14 more neutrons than V. 3 The relative atomic mass of iron in this sample is 54.1. 4 V2+ is deflected more than W2+ in the same electric field. A 1, 2, 3 and 4 B 2, 3 and 4 only C 2 and 3 only D 1 and 4 only

3 © DHS 2024 8873/01 [Turn over 3 Which row about the similarity and difference between a 2px and a 3pz orbital is correct? similarity difference A number of lobes per orbital orientation of orbital in space B size of orbital shape of orbital C orientation of orbital in space size of orbital D shape of orbital number of lobes per orbital 4 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 5 Which statement helps to explain why iodine has a larger atomic radius than chlorine? A Iodine is less electronegative than chlorine. B Iodine has more filled electron shells than chlorine. C Iodine has a greater number of protons than chlorine. D Iodine is a solid while chlorine is a gas under room conditions.

4 © DHS 2024 8873/01 6 Use of the Data Booklet is relevant to this question. Which solid has the largest magnitude of lattice energy? A NaF B Na2O C MgF2 D MgO 7 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 8 Use of the Data Booklet is relevant to this question. Which contains the smallest number of the stated particles? A ions in 80 cm3 of 0.1 mol dm−3 of Na2SO4 B molecules in 4 g of liquid bromine C molecules in 500 cm3 of hydrogen (measured at r.t.p.) D atoms in 1 cm3 of pure water (density = 1 g cm−3)

5 © DHS 2024 8873/01 [Turn over 9 Which statement is correct? A One mole of a compound is the amount that contains the same number of atoms as there are atoms in 12.000 g of carbon-12. B The relative isotopic mass of lithium-7 is given by the following expression. average mass of all isotopes of lithium 1 12 the mass of one atom of carbon-12 C The relative atomic mass of oxygen is given by the following expression. average mass of one atom of oxygen 1 12 the mass of one atom of carbon-12 D The relative molecular mass of a compound E is given by the following expression. average mass of one atom of E 1 12 the mass of one atom of carbon-12 10 Use of the Data Booklet is relevant to this question. An excess of solid potassium iodide is added to a 25 cm 3 solution containing an unknown amount of dichromate(VI), Cr2O72−. During the reaction, dichromate( VI) ions are reduced to chromium(III), Cr3+, while iodine is liberated from iodide ions. The iodine liberated is then titrated against 0.010 mol dm −3 sodium thiosulfate solution, Na2S2O3. The following reaction occurs and 22.50 cm3 of Na2S2O3 solution is required to reach the end-point. I2 + 2S2O32– → 2I– + S4O62– What is the concentration, in mol dm−3, of Cr2O72− ions in the original solution? A 3.75 × 10−5 B 1.50 × 10−3 C 4.50 × 10−3 D 1.80 × 10−2

6 © DHS 2024 8873/01 11 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 shake with an excess of dilute NaOH(aq) colourless alkaline 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 12 The graph shows how property W varies with the Period 3 elements, E1, E2 and E3. elements property W E1 E2 E3 Which combination of property W and elements is correct? property W E1 E2 E3 A first ionisation energy Mg S P B electronegativity Al Si Cl C melting point Al Na P D electrical conductivity S Na Si

7 © DHS 2024 8873/01 [Turn over 13 Aluminium chloride and phosphorus(V) chloride were separately reacted with water. Which statement about these reactions is correct? A The solutions formed turn red litmus paper blue. B The chlorides react slowly with water, producing acidic fumes. C The solutions formed have a lower pH than aqueous sodium chloride. D The chlorides completely hydrolyse in water to produce acidic solutions. 14 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

8 © DHS 2024 8873/01 15 N2O5 is unstable and decomposes. 2N2O5 → 4NO2 + O2 An experiment to study this reaction under certain conditions gave the following results. time / s [N2O5] / mol dm−3 0 0.040 5 0.028 10 0.020 15 0.014 20 0.010 What is the half-life of this reaction and the units of the rate constant, k? half-life / s units of k A 10 s−1 B 20 s−1 C 10 mol dm−3 s−1 D 20 mol dm−3 s−1

9 © DHS 2024 8873/01 [Turn over 16 Under acidic conditions, bromate(V) ions and bromide ions react as shown. BrO3− + 5Br− + 6H+ → 3Br2 + 3H2O A chemist performed a series of experiments to investigate the effect of changes in concentration on the rate of this reaction. The initial concentration and rate data obtained for each experiment is given in the table below. experiment initial [BrO3−] / mol dm−3 initial [Br−] / mol dm−3 initial [H+] / mol dm−3 initial rate / mol dm−3 h−1 1 2.0 × 10−3 2.0 × 10−3 2.0 × 10−3 3.0 × 10−3 2 4.0 × 10−3 2.0 × 10−3 2.0 × 10−3 6.0 × 10−3 3 2.0