Dunman (2024) 4E 6092 Prelim P1

This document consists of 17 printed pages and 1 blank page. DUNMAN SECONDARY SCHOOL CANDIDATE NAME CLASS INDEX NUMBER PRELIMINARY EXAMINATION 2024 SECONDARY 4 EXPRESS CHEMISTRY 6092/01 Paper 1 16 August 2024 1 hour Additional Materials: Multiple Choice Answer Sheet READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, glue or correction fluid. Write your name, class and index number on the Answer Sheet in the spaces provided unless this has been done for you. There are forty 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. A copy of the Periodic Table is printed on page 18. The use of an approved scientific calculator is expected, where appropriate.

2 6092/01/Prelim/4Exp/2024 1 A student investigates the rate of reaction between an excess of acid of different concentrations and known quantity of calcium carbonate granules. During the reaction, the student measures the volume of gas released. In addition to a conical flask and a balance, the following pieces of apparatus are available. 1 gas syringe 2 thermometer 3 measuring cylinder 4 stopwatch Which pieces of apparatus are needed for this experiment? A 1, 3 and 4 only B 1 and 3 only C 1 and 4 only D 2, 3 and 4 only 2 The diagram shows an experimental setup to produce and collect a dry sample of gas X. What is gas X? A ammonia gas B hydrogen chloride gas C hydrogen gas D steam gas X concentrated sulfuric acid

3 6092/01/Prelim/4Exp/2024 3 Aluminium sulfate is used in water treatment. Aqueous aluminium sulfate is acidic. The table shows the results of tests on four different samples of treated water. To which sample had an excess of aluminium sulfate been added? pH of sample reaction with an excess aqueous ammonia A 3 white precipitate B 3 no reaction C 11 no reaction D 11 white precipitate 4 The diagrams show an experiment with aqueous ammonium chloride. A gas, Y, is produced and the litmus paper changes colour. What are solution X and gas Y? solution X gas Y A aqueous sodium hydroxide ammonia B aqueous sodium hydroxide chlorine C dilute sulfuric acid ammonia D dilute sulfuric acid chlorine poured in moist litmus paper mixture heat aqueous ammonium chloride

4 6092/01/Prelim/4Exp/2024 5 The cover plate is removed from the gas jars shown in the diagram. After several days, the colour of the gas is the same in both jars. Which statement explains this change? A Equal volumes of oxygen and bromine contain equal numbers of molecules. B Oxygen and bromine molecules diffuse at the same rate. C Oxygen and bromine molecules move randomly in all directions. D Oxygen and bromine gases have equal densities. 6 An element J has a nucleon number of 45. The ion, J3+, contains 18 electrons. How many neutrons are there in an atom of J? A 18 B 21 C 24 D 27 7 Phosphorus trichloride, PCl3, is a molecule formed when the elements phosphorus and chlorine react together. How many electrons in the outer shell of the phosphorus atom are not involved in bonding? A 0 B 1 C 2 D 3 oxygen cover plate bromine

5 6092/01/Prelim/4Exp/2024 8 Which statements are correct for both metals and ionic compounds? 1 They conduct electricity because electrons flow through the solid materials. 2 They contain positive ions. 3 Most have high melting points. A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only 9 Which statement explains why potassium chloride, KCl, has a lower melting point than calcium oxide, CaO? A Potassium chloride is covalent but calcium oxide is ionic. B Potassium is more reactive than calcium. C The attraction between K+ and Cl- is weaker than that between Ca2+ and O2-. D The melting point of potassium is lower than that of calcium.

6 6092/01/Prelim/4Exp/2024 10 Which diagram best represents the structure of a mixture? A B C D 11 In which reaction does the biggest percentage change in volume occur? A C3H8 (g) + 5O2 (g) → 3CO2 (g) + 4H2O (l) B 4NH3 (g) + 3O2 (g) → 2N2 (g) + 6H2O (l) C CH4 (g) + 2O2 (g) → CO2 (g) + 2H2O (l) D 2SO2 (g) + O2 (g) → 2SO3 (g) 12 In a reaction between 23 g of ethanol and excess hydrogen chloride, the mass of chloroethane obtained is 20 g. C2H5OH + HCl → C2H5Cl + H2O What is the percentage yield of chloroethane? [Mr: C2H5OH, 46; C2H5Cl, 64.5] A 15% B 46% C 62% D 87%

7 6092/01/Prelim/4Exp/2024 13 20 cm3 of an aqueous 1.0 mol/dm3 solution of the hydroxide of metal X exactly neutralises 40cm3 of 0.25 mol/dm3 dilute sulfuric acid. What is the formula for the sulfate of X? A XSO4 B X(SO4)2 C X2SO4 D X2(SO4)3 14 A volume of ethane, C2H6, at room temperature and pressure, has a mass of 20 g. What is the mass of an equal volume of propene, C3H6, at r.t.p.? A 20 g B 21 g C 28 g D 42 g 15 Dilute aqueous sodium chloride and concentrated aqueous sodium chloride are electrolysed using inert electrodes in separate experiments. Which row shows the products of these experiments? dilute aqueous sodium chloride concentrated aqueous sodium chloride positive electrode negative electrode positive electrode negative electrode A chlorine hydrogen chlorine sodium B chlorine oxygen oxygen hydrogen C oxygen hydrogen chlorine hydrogen D oxygen hydrogen hydrogen chlorine

8 6092/01/Prelim/4Exp/2024 16 The diagram shows a simple cell. Which statements about the cell are correct? 1 Electrons pass from magnesium electrode to silver electrode through electrolyte. 2 The iron electrode is the negative electrode. 3 The magnesium electrode loses electrons. 4 Bubbles are formed around iron. A 1, 2, 3 and 4 B 1 and 4 only C 2 and 3 only D 3 and 4 only 17 Which statement describes what happens when hydrogen and oxygen are used in a fuel cell? A Electricity is generated directly. B Electricity is used to produce water. C Hydrogen is burned to form steam. D Hydrogen reacts to form a hydrocarbon fuel. 18 In an electrolysis experiment, the same amount of charge deposited 54.0 g of silver and 5.2 g of chromium. What is the charge on the chromium ion? A +2 B +3 C +5 D +6 magnesium iron voltmeter dilute sulfuric acid

9 6092/01/Prelim/4Exp/2024 19 In which process is energy released? A electrolysis of water to form hydrogen and oxygen B photosynthesis C reaction between dilute sulfuric acid with aqueous sodium hydroxide D thermal decomposition of calcium carbonate 20 The equation and the energy profile diagram for a reversible reaction are shown. P + Q ⇌ R + S What is the enthalpy change of reaction, ΔH and activation energy, Ea for the reverse reaction? ΔH in kJ / mol Ea in kJ / mol A - 50 120 B + 50 120 C - 50 170 D + 50 170 energy 200 80 30 progress of reaction P + Q R + S

10 6092/01/Prelim/4Exp/2024 21 The rate of reaction between calcium carbonate and hydrochloric acid is measured in three separate experiments. The conditions at which each experiment is performed are as follows: experiment particle size of calcium carbonate volume of acid concentration of acid (mol/dm3) 1 powdered in excess 2.0 2 lumps in excess 2.0 3 lumps not in excess 1.0 The results of these experiments are shown. Which row shows