YSS 4E Pure Chem Paper 1 Prelim 2024

[Turn over YISHUN SECONDARY SCHOOL PRELIMINARY EXAMINATION 2024 SECONDARY 4 EXPRESS CANDIDATE NAME CLASS INDEX NUMBER CHEMISTRY 6092/01 Paper 1 Multiple Choice 28 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. There are forty questions on this paper. Answer all questions. For each question there are four possible answers A, B, C or 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. This document consists of 17 printed pages and 1 blank page.

2 1 A student wants to investigate if dissolving 2.35 g of a salt in 25.0 cm3 of water is an endothermic process. Which pieces of apparatus are required? electronic balance measuring cylinder stopwatch thermometer A ✓ ✓ × ✓ B ✓ × × ✓ C × ✓ × ✓ D ✓ × ✓ × 2 The apparatus shown was used to compare the rate of diffusion between gas J and air. A beaker containing the gas was placed over the porous pot. Which gas would cause bubbles to be observed in the beaker of water? A carbon monoxide B ethane C helium D sulfur dioxide gas J porous pot water air beaker

3 [Turn over 3 A paper chromatogram was prepared using a mixture of coloured substances. After drying, the chromatogram is shown. Which statement is correct? A Locating agents are always needed to interpret a chromatogram. B The chromatography paper must have been placed with the solvent above level Z. C The substance at level X has a lower Rf value than the substance at level Y. D The substance at level X is more soluble than the substance at level Y in the solvent. 4 The graph shows the change in temperature with time when steam is cooled from 120 °C to ‒20 °C. Which row shows the correct change taking place between different points of the graph? points change A P to Q kinetic energy of particles remains constant B Q to R water boiling C R to S volume of liquid is decreasing D T to U water freezing temperature/°C 120 time/s ‒20 P Q / R S T U solvent front start line

4 5 Particles of four elements are shown. Ne10 20 N7 15 3– O8 16 2– F9 17 ‾ Which statement about all four particles is correct? A They have the same number of electrons. B They have the same number of neutrons. C They have the same number of nucleons. D They have the same number of protons. 6 The compound C2H3Br3 contains only the 12C isotope of carbon and the 1H isotope of hydrogen. The two stable isotopes of bromine are 79Br and 81Br. Using these two isotopes of bromine, how many different relative molecular masses are possible for C2H3Br3? A 2 B 3 C 4 D 5 7 Some properties of four substances are shown in the table. Which substance is silver chloride? state at room temperature electrical conductivity at room temperature electrical conductivity when molten electrical conductivity when added to water A liquid × × ✓ B solid ✓ ✓ insoluble C solid × ✓ ✓ D solid × ✓ insoluble 8 Which two substances have similar three-dimensional arrangements of their atoms? A diamond and silicon dioxide B graphite and diamond C carbon dioxide and graphite D silicon dioxide and carbon dioxide

5 [Turn over 9 Two elements, W and X, form a compound of formula WX3. A ‘dot-and-cross’ diagram of a molecule of WX3 is shown. Only the outer shell electrons are shown. Which statement is not correct? A The molecule contains a total of eight electrons. B W and X are both non-metals. C W is in Group 15 of the Periodic Table. D X is hydrogen. 10 In the liquid state, which substance conducts electricity using mobile electrons? A ammonia B ammonium bromide C copper D copper(II) chloride 11 Which substance has 7.2 × 1023 atoms? A 0.2 mol of magnesium metal B 0.3 mol of ammonia gas C 0.4 mol of hydrogen chloride D 1.2 mol of carbon dioxide gas 12 Which compound contains the highest percentage of sulfur by mass? A SO2 B H2SO4 C Na2S D PbS2

6 13 The empirical formula of cyanogen gas is CN. 1.3 g of cyanogen gas occupied 600 cm3 at room temperature and pressure. What is the molecular formula of cyanogen? A CN B C2N2 C C3N3 D C4N4 14 The diagram shows three balloons filled with different gases at room temperature and pressure. Three statements were made about the balloons. 1 The number of moles of gases in the 3 balloons is the same. 2 The number of molecules in the 3 balloons is different. 3 The mass of gases in the 3 balloons is different. Which statements are correct? A 1 and 2 B 1 and 3 C 2 and 3 D 1, 2 and 3

7 [Turn over 15 When excess aqueous barium chloride is added to 25.0 cm 3 of 1.00 mol/dm 3 sodium sulfate, a white precipitate of barium sulfate is formed. Na2SO4(aq) + BaCl2(aq) → BaSO4(s) + 2NaCl(aq) The precipitate is filtered off, washed, dried and weighed. 5.36 g barium sulfate is obtained. What is the percentage yield of barium sulfate? A 2.3 % B 27 % C 92 % D 97 % 16 Which equation represents the ionic equation of the reaction between zinc and dilute hydrochloric acid? A Zn(s) + 2H+(aq) → Zn2+(aq) + H2(g) B Zn(s) + 2H+(aq) → Zn2+(aq) + 2H(aq) C Zn(s) + 2HCl(aq) → ZnCl2(s) + H2(g) D Zn(s) + 2HCl(aq) → Zn2+(aq) + 2Cl–(aq) + H2(g) 17 Excess aqueous ammonia is added to a solution containing aluminium ions, copper( II) ions and zinc ions. The mixture is then filtered. Which ions will be found in the resulting residue? A aluminium ions B aluminium ions and zinc ions C copper(II) ions D copper(II) ions and zinc ions 18 Which three salts are all prepared by precipitation? A barium sulfate, calcium nitrate, silver chloride B barium sulfate, lead(II) chloride, silver nitrate C calcium sulfate, lead(II) sulfate, silver chloride D calcium sulfate, lead(II) sulfate, silver nitrate

8 19 Which graph shows the changes in pH as an excess of aqueous sodium hydroxide is added gradually to hydrochloric acid solution? 20 In the manufacture of ammonia, which action will help to reduce costs while maintaining a good yield of ammonia? A adding more iron catalyst to the reaction mixture B decreasing the volumes of nitrogen and hydrogen gases added C increasing the pressure exerted on the reaction mixture D pumping unreacted nitrogen and hydrogen gases back for further reaction volume of sodium hydroxide added / cm3 volume of sodium hydroxide added / cm3 volume of sodium hydroxide added / cm3 volume of sodium hydroxide added / cm3

9 [Turn over 21 Gaseous compound Y is an oxidising agent. Y is bubbled through separate solutions of potassium iodide and acidified potassium manganate(VII). Which row shows the colour changes when Y is bubbled through these two solutions? potassium iodide solution acidified potassium manganate(VII) solution A colourless to brown purple to colourless B colourless to brown solution remains purple C solution remains colourless solution remains purple D solution remains colourless purple to colourless 22 Sulfur dioxide is an atmospheric pollutant that causes acid rain. One of the reactions in this process is the conversion of su