2024 EJC H1 Chemistry Prelims P1 QP

© EJC [Turn Over EUNOIA JUNIOR COLLEGE JC2 Preliminary Examination 2024 General Certificate of Education Advanced Level Higher 1 CHEMISTRY Paper 1 Multiple Choice 8873/01 18 September 2024 1 hour Additional Materials: Multiple Choice Answer Sheet Data Booklet READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, glue or correction fluid. Write your name, civics group and registration number on the Answer Sheet in the spaces provided unless this has been done for you. 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 question paper. The use of an approved scientific calculator is expected, where appropriate. This document consists of 11 printed pages and 1 blank page.

2 © EJC 8873/01/J2Prelims/24 1 Use of the Data Booklet is relevant to this question. In the analysis of an oxide of nitrogen, NxOy, 0.10 mol of the oxide were reacted with excess hydrogen under suitable conditions. 32 2 N O xNH H OH xy y⎯⎯⎯ → + 3.6 g of water were formed in this reaction, while the ammonia produced required 100 cm3 of 1.0 mol dm–3 HCl(aq) for neutralisation. What is the formula of the oxide of nitrogen analysed? A NO B NO2 C N2O D N2O5 2 The isotopic composition of an element is shown. What is the Ar of the element? A 10.2 B 10.5 C 10.8 D 11.0 5 4 3 2 1 0 relative abundance 9 10 11 12 mass number of isotopes

3 © EJC 8873/01/J2Prelims/24 [Turn over 3 Three chemical reactions involving hydrogen peroxide, H2O2, are shown. reaction 1 H2O2 + 2HI → 2H2O + I2 reaction 2 5H2O2 + 2KMnO4 + 3H2SO4 → 5O2 + 2MnSO4 + 8H2O + K2SO4 reaction 3 2H2O2 → 2H2O + O2 Which row identifies the reaction in which the oxygen of hydrogen peroxide undergoes oxidation, reduction and disproportionation? oxidation reduction disproportionation A reaction 1 reaction 2 reaction 3 B reaction 2 reaction 1 reaction 3 C reaction 2 reaction 3 reaction 1 D reaction 3 reaction 1 reaction 2 4 The table below shows the composition of the nucleus in some particles. particle number of neutrons number of nucleons P– 21 40 Q+ 18 38 R2– 19 39 S2+ 20 41 Which of the following pairs consists of particles that are isoelectronic? A Q+ and R2– B Q+ and S2+ C P– and R2– D R2– and S2+ 5 When a beam of protons travelling at the same speed passes through an electric field of constant strength, the protons, 1H+, are deflected through an angle of +15º. Under identical conditions, which particle would be deflected through an angle of +5º? A 2H+ B 3He2+ C 6Li2+ D 12C3+

4 © EJC 8873/01/J2Prelims/24 6 Silica, SiO2, is a major constituent of sand. In the structure of solid SiO2, • each silicon atom is bonded to x oxygen atoms, • each oxygen atom is bonded to y silicon atoms, • each bond is z in nature. What is the correct combination of x, y and z? x y z A 2 1 covalent B 2 1 intermolecular C 4 2 covalent D 4 2 intermolecular 7 In which pair of molecules do the values of the bond angles differ the greatest? A BF3 and NH3 B BF3 and SF6 C CH4 and NH3 D CH4 and SF6 8 In group 17 elements, the F─F bond is weaker than the Cl─Cl bond. Hence, fluorine has higher reactivity than chlorine. Which statement best accounts for the weaker F─F bond? A greater repulsion between the lone pair of electrons B smaller nuclear charge of the fluorine atom C greater effective overlap between orbitals D shorter length of the bond

5 © EJC 8873/01/J2Prelims/24 [Turn over 9 The boiling points of hydrogen bromide, HBr, and hydrogen chloride, HC l, are shown in the table. HCl HBr boiling point / ºC –85 –67 Which statements explain the increase in boiling points from hydrogen chloride to hydrogen bromide? 1 Covalent bonds between atoms increase in strength. 2 Hydrogen bonds between the molecules increase in strength. 3 Induced dipole forces between molecules increase in strength. A 1 and 2 B 2 and 3 C 2 only D 3 only 10 Which of the following statements is incorrect? A Bond energy is the energy required to break 1 mole of covalent bonds between two atoms in the gaseous state. B The enthalpy change of neutralisation between any strong acid and strong base is about –57.0 kJ mol–1. C Third ionisation energy of aluminium is the energy needed to convert 1 mole of Al(g) into 1 mole of Al3+(g). D Lattice energy always has an exothermic value. 11 Fe2O3 reacts with CO during the process of extraction from the haematite ore. Fe2O3(s) + 3CO(g) → 2Fe(s) + 3CO2(g) H = –26.8 kJ mol−1 FeO(s) + CO(g) → Fe(s) + CO2(g) H = –16.5 kJ mol−1 What is the value of ∆H1? A –59.8 kJ mol−1 B –43.3 kJ mol−1 C –10.3 kJ mol−1 D +6.2 kJ mol−1 ∆H1 + 2CO(g) + 2CO(g) 2FeO(s) + CO2(g) Fe2O3(s) + CO(g) 2Fe(s) + 3CO2(g)

6 © EJC 8873/01/J2Prelims/24 12 The equations show some reactions which occur in the upper atmosphere. O3 → O + O2 NO + O3 → NO2 + O2 NO2 + O → NO + O2 Which statements are correct? 1 Oxygen free radicals are formed by the action of ultraviolet light. 2 NO acts as a catalyst. 3 NO acts as an oxidising agent. A 1 and 3 B 1 and 2 C 2 and 3 D 3 only 13 The Maxwell-Boltzmann distribution of molecular energies is useful for explaining why increasing temperature affects the rate of a chemical reaction. Which of the following statements describes how the shape of the Maxwell -Boltzmann distribution curve changes as temperature increases? A The peak decreases in height and moves to the left. B The peak increases in height and moves to the left. C The peak decreases in height and moves to the right. D The peak increases in height and moves to the right 14 A catalyst is added to a system in equilibrium. What is the effect on the rates of the forward and reverse reactions? A There is no effect on the rate in either direction. B Both rates increase by the same factor. C The rate in the forward direction increases by a greater factor than the reverse direction. D The rate in the reverse direction increases by a greater factor than the forward direction.

7 © EJC 8873/01/J2Prelims/24 [Turn over 15 The following equilibrium is established between H2S and SO2. 2H2S(g) + SO2(g)  3S(s) + 2H2O(g) H is negative Which statements are correct? 1 Increases in temperature increases rate and decreases yield. 2 Increases the concentration of H2S decreases rate and decreases yield. 3 Decreases in pressure decreases rate and decreases yield. A 1 and 3 B 1 and 2 C 2 and 3 D 3 only 16 Four equilibrium reactions are set up. The concentration of each gas in the equilibrium mixtures is 0.1 mol dm−3. Which equilibrium has a numerical Kc value of 0.01? A CH4(g) + 2H2O(g)  CO2(g) + 4H2(g) B N2(g) + 3H2(g)  2NH3(g) C H2(g) + I2(g)  2HI(g) D 2NO2(g)  N2O4(g) 17 Which reaction involves both Arrhenius acid and Arrhenius base behaviour? A 2HCl + Na2CO3 → 2NaCl + CO2 + H2O B HNO3 + NH3 → NH4NO3 C HCl + H2O → H3O+ + Cl− D HNO3 + KOH → KNO3 + H2O 18 20 cm3 of 0.1 mol dm −3 H2SO4 was added to 80 cm 3 of 0.1 mol dm −3 of NaOH. What is the pH of the final solution at 25 ºC? A 12.8 B 12.6 C 11.8 D 11.6

8 © EJC 8873/01/J2Prelims/24 19 The normal pH range of blood is 7.35–7.45. During exercise, lactic acid is produced. Which reaction occurs during exercise to maintain the pH of blood? A H2CO3 + OH− → HCO – 3 + H2O B HCO – 3 + OH− → CO 2– 3 + H2O C HCO – 3 + H3O+ → H2CO3 + H2O D CO 2– 3 + H3O+ → HCO – 3 + H2O 20 Which prop