Copy of CHS 2024 S4 OP Prelim Paper 1

[Turn Over Name: Index Number: Class: CATHOLIC HIGH SCHOOL Preliminary Examination Secondary 4 ‘O’ Level Programme CHEMISTRY 6092/01 Paper 1 27 August 2024 1 hour Additional Materials: Multiple Choice Answer Sheet READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, pencil clips, glue or correction fluid. Write your name, index number and class on the Answer Sheet in the spaces provided. There are forty questions in 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. 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. A copy of the Periodic Table is given on page 16. The use of an approved scientific calculator is expected, where appropriate. For examiner’s use only: Total / 40 This document consists of 16 printed pages.

2 1 When calcium carbonate is added to dilute hydrochloric acid, carbon dioxide gas is released. Three sets of apparatus are shown. 1 2 3 Which sets of apparatus are suitable, together with a stopwatch, for following the rate of this reaction? A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only 2 Solutions of Ca(NO3)2 and Cu(NO3)2 separately undergo a series of reactions. Ca(NO3)2(aq) J K L Cu(NO3)2(aq) M N O J, K and L are calcium compounds. M, N and O are copper(II) compounds. How many of J, K, L, M, N and O contain precipitates? A 2 B 3 C 4 D 5 Na2CO3(aq) Na2CO3(aq) excess HCl(aq) excess HCl(aq) excess NH3(aq) excess NH3(aq)

3 [Turn Over 3 An excess of sodium hydroxide solution is added to a solution of salt P and warmed. A gas that turns damp red litmus paper blue is only given off after aluminium foil is added to the hot solution. What is salt P? A ammonium chloride B ammonium nitrate C sodium chloride D sodium nitrate 4 The diagram shows the apparatus used to separate hexane (boiling point, 70 oC) and heptane (boiling point, 98 oC). Which graph would be obtained if the temperature at point Q was plotted against the total volume of distillate collected? A B C D Q distillate water in water out thermometer heat temperature / oC total volume of distillate / cm3 70 80 90 100 temperature / oC total volume of distillate / cm3 70 80 90 100 temperature / oC total volume of distillate / cm3 70 80 90 100 temperature / oC total volume of distillate / cm3 70 80 90 100

4 5 Four experiments, each containing a different acidic gas, are set up as shown. The dividing glass plates are removed at the same time. In which set of apparatus does the litmus paper turn red first? A B C D 6 The melting points and boiling points of four elements are shown. element melting point / oC boiling point / oC W −183 −89 X −78 −33 Y −7 59 Z 44 280 In which elements are the particles far apart at 0 oC? A W and X B X and Y C X and Z D Y and Z 7 In which species are the numbers of protons, neutrons and electrons all different? A Al13 27 B Cl− 17 35 C S2− 16 32 D K+ 19 39

5 [Turn Over 8 Which molecule has an equal number of valence electrons involved in bonding and not involved in bonding? A CH4 B H2O C NH3 D O2 9 Which statement explains why sodium chloride, NaC l, has a lower melting point than magnesium oxide, MgO? A Sodium chloride has a simple molecular structure while magnesium oxide has a giant ionic structure. B Sodium is more reactive than magnesium. C The attraction between Na+ and Cl− is weaker than that between Mg2+ and O2−. D The particles in sodium chloride are more closely packed than in magnesium oxide. 10 In the structure of solid SiO2, • each silicon atom is bonded to x oxygen atoms • each oxygen atom is bonded to y silicon atoms • the bonding is z. What is the correct combination of x, y and z in these statements? x y z A 2 1 covalent B 2 1 ionic C 4 2 covalent D 4 2 ionic 11 Which statement is correct? A 1.00 mol of zinc chloride contains 1.20 × 1024 ions. B 2.00 mol of sodium nitrate contains 1.20 × 1024 ions. C 24.0 dm 3 of chlorine gas, measured at room temperature and pressure, contains 1.20 × 1024 atoms. D 48.0 dm 3 of hydrogen gas, measured at room temperature and pressure, contains 1.20 × 1024 atoms.

6 12 Calcium oxide and magnesium sulfide each reacts with acid. CaO(s) + 2H+(aq) → Ca2+(aq) + H2O(l) MgS(s) + 2H+(aq) → Mg2+(aq) + H2S(g) A mixture of these two compounds, X, reacts with exactly 0.125 mol of dilute hydrochloric acid. The amount of hydrogen sulfide formed is 0.0250 mol. What is the mass of calcium oxide in mixture X? A 2.1 g B 2.8 g C 4.2 g D 5.6 g 13 The formula of an oxide of element Y is Y2O5. 5.4 g of Y2O5 contains 1.4 g of Y. How many moles of Y does 1.4 g of the element contain? A 1.4 16 × 2 5 B 1.4 16 × 5 2 C 4.0 16 × 2 5 D 4.0 16 × 5 2 14 Which statements about hydrogen–oxygen fuel cells are correct? 1 A hydrogen-oxygen fuel cell is used to generate electricity. 2 Hydrogen is extracted from clean, dry air. 3 The waste product in a hydrogen-oxygen fuel cell is water. A 1 only B 1 and 2 only C 1 and 3 only D 2 and 3 only 15 Aqueous copper(II) sulfate is electrolysed using copper electrodes. Which row correctly describes what happens? colour of electrolyte mass of anode mass of cathode A becomes colourless decreases decreases B becomes colourless remains the same increases C remains blue remains the same decreases D remains blue decreases increases

7 [Turn Over 16 Hydrogen reacts with iodine to form hydrogen iodide. The equation for the reaction and enthalpy change are shown. H2(g) + I2(g) → 2HI(g) H = +27 kJ/mol What can be deduced from this information? A The energy absorbed in forming bonds is greater than the energy released in breaking bonds. B The energy absorbed in forming bonds is less than the energy released in breaking bonds. C The energy released in forming bonds is greater than the energy absorbed in breaking bonds. D The energy released in forming bonds is less than the energy absorbed in breaking bonds. 17 Under certain conditions, nitrogen reacts with oxygen to form N2O. 2N2(g) + O2(g) ⇌ 2N2O(g) The energy profile diagram is shown. What is the activation energy of the reverse reaction? A –447 kJ/mol B –283 kJ/mol C +164 kJ/mol D +283 kJ/mol

8 18 During the Contact process, sulfuric acid, H2SO4, is produced from sulfur in a series of stages. The sulfur compound produced in each stage is shown. S → SO2 → SO3 → H2S2O7 → H2SO4 Which statement correctly describes these stages? A All stages involve oxidation and the highest oxidation state of sulfur is +12. B Only three of the stages involve oxidation and the highest oxidation state of sulfur is +6. C Only three of the stages involve oxidation and the highest oxidation state of sulfur is +12. D Only two of the stages involve oxidation and the highest oxidation state of sulfur is +6. 19 The decomposition of hydrogen peroxide in the presence of MnO2 is shown. 2H2O2(aq) → 2H2O(l) + O2(g) The volume of gas collected when 0.2 g of MnO2 is added to two different hydrogen peroxide solutions at 20 oC is shown on the graph as curves X and Y. Which row shows the conditions that will result in curves X and Y?