2025 JYSS Pure Chem Prelim P1

JUNYUAN SECONDARY SCHOOL PRELIMINARY EXAMINATION 2025 SECONDARY FOUR EXPRESS CANDIDATE NAME CLASS INDEX NUMBER CHEMISTRY 6092 PAPER 1 Multiple Choice 1 September 2025 1 hour Additional Materials: Multiple Choice Answer Sheet READ THESE INSTRUCTIONS FIRST Write your name, class and index number on all the work you hand in. Write in soft pencil. Do not use paper clips, glue or correction fluid. 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 17. The use of an approved scientific calculator is expected, where appropriate. This document consists of 17 printed pages and 1 blank page. [Turn over 4 D

2 6092/01/Prelim/25 1 Oxygen was prepared from hydrogen peroxide and collected as shown in the diagram. 2H2O2 → 2H2O + O2 The first few tubes of gas were rejected because the gas was contaminated by A water vapour. B hydrogen peroxide. C hydrogen. D nitrogen. 2 Three separations are listed. 1 obtaining water from aqueous sodium chloride 2 obtaining iodine from a solid mixture of iodine and nickel 3 obtaining solid sodium chloride from aqueous sodium chloride Which techniques would be involved in these separations? 1 2 3 A distillation sublimation evaporation B distillation sublimation filtration C filtration crystallisation evaporation D sublimation crystallisation filtration

3 [Turn over 6092/01/Prelim/25 3 A student sets up the following experiment to separate a mixture containing four alcohols. The table shows the boiling points of the four alcohols used. alcohol boiling point / oC butanol 117 ethanol 79 pentanol 138 propanol 97 The student manages to collect only two alcohols from the mixture. Which alcohols did he fail to obtain? A butanol and ethanol B butanol and pentanol C ethanol and propanol D pentanol and propanol

4 6092/01/Prelim/25 4 In which state does 1 dm3 of ethene contain the most amount of particles? A gas at 100 oC B gas at room temperature C liquid D solid 5 The heating curve of an impure sample of X is shown below. What are the melting point and boiling point of pure substance X? melting point / oC boiling point / oC A 45 129 B 47 128 C 48 127 D 49 130

5 [Turn over 6092/01/Prelim/25 6 Solid amonium chloride decomposes on heating according to the following equation. NH4Cl(s) → NH3(g) + HCl(g) Which change occurs to the damp red litmus paper in the experiment above? A remains red B turns blue and is then bleached C turns blue and remains blue D turns blue and then turns red 7 Chlorine-35 and chlorine-37 are two isotopes of chlorine. Which statements are correct? 1 They have the same atomic number. 2 They have the same mass number. 3 They have the same physical properties. 4 They have the same chemical properties. A 1 and 2 only B 1 and 4 only C 2 and 3 only D 2 and 4 only 8 Which of the following statements is true? A Ar has more electrons than Cl‒. B Cl‒ has more electrons than K+. C Fe3+ has more electrons than Fe2+. D K has more electrons than K+.

6 6092/01/Prelim/25 9 The formulae of four covalent molecules are shown. 1 H2O 2 CO2 3 CH3OH 4 CH3COOH In which pair of molecules does oxygen form at least one double bond in both molecules? A 1 and 2 B 1 and 3 C 2 and 4 D 3 and 4 10 The ion QH4+ can be represented by the ‘dot and cross’ diagram shown. To which Group in the Periodic Table does Q belong? A 1 B 13 C 14 D 15 11 Carbon exists as different forms such as graphite , diamond and, carbon nanotubes as shown. carbon nanotube Which statement best describes a property of the carbon nanotube and a suitable use? property use A conducts electricity as a lubricant in machines B conducts electricity in electronic circuits C flexible as pencil leads D flexible in jewellery

7 [Turn over 6092/01/Prelim/25 12 The formula of a nitride of element X is X3N2. 23.8 g of X3N2 contains 4.5 g of X. How many moles of X does 4.5 g of the element contain? A 19.3 14 x 2 3 B 19.3 14 x 3 2 C 9.65 14 x 2 3 D 9.65 14 x 3 2 13 Glucose has a relative molecular mass, Mr, of 180. How many grams of glucose are added to 50 cm 3 of water to make a solution of concentration 0.4 mol/dm3? A 3.6 B 9.0 C 36 D 72 14 What is the ratio of the volume of 2 g of hydrogen to the volume of 16 g of methane, both volumes at room temperature and pressure? A 1:1 B 1:2 C 1:8 D 2:1 15 When 42.0 g of sodium hydrogen carbonate, NaHCO 3 (Mr = 84) , was strongly heated, 3.00 dm3 of carbon dioxide gas, measured at room temperature and pressure was released. 2NaHCO3 → Na2CO3 + H2 O + CO2 What was the percentage yield of carbon dioxide? A 25% B 50% C 75% D 100%

8 6092/01/Prelim/25 16 The following shows a graph of pH against volume of solution added in an acid -alkali titration. Which of the following statements about the titration is correct? 1 20.0 cm3 of alkali neutralised the acid. 2 Aqueous sodium hydroxide was added dropwise to dilute ethanoic acid. 3 Dilute hydrochloric acid was added dropwise to aqueous sodium hydroxide. 4 Universal Indicator is a suitable indicator for this titration. A 1 and 2 only B 2 and 4 only C 1 and 3 only D 3 and 4 only 17 Glass is silicon dioxide. Which of the following correctly explains why the respective substance can be added to dissolve glass fragments? substance added explanation A zinc oxide reacts with amphoteric oxides B aqueous sodium hydroxide reacts with acidic oxides C dilute sulfuric acid reacts with basic oxides D ethanol reacts with organic compounds volume of solution added / cm3

9 [Turn over 6092/01/Prelim/25 18 Which three salts are prepared by precipitation? A barium sulfate, calcium nitrate, lead(II) sulfate B barium sulfate, calcium nitrate, silver chloride C barium sulfate, lead(II) sulfate, silver chloride D calcium nitrate, lead(II) sulfate, silver chloride 19 A coin is analysed by dissolving it in nitric acid. To the resulting solution, an excess of aqueous ammonia is added and the mixture is filtered. A brown precipitate remains in the filter paper and a deep blue solution is obtained as the filtrate. Which metals does the coin contain? A aluminium and copper B copper and iron C iron and zinc D zinc and copper 20 Some chemical tests are performed on a sample of polluted gas. The results are shown as follows: 1 white precipitate forms in limewater 2 moist blue litmus turns red 3 acidified potassium manganate(VII) turns colourless What gases are present in the sample? A carbon dioxide and sulfur dioxide B carbon monoxide and ammonia C chlorine and carbon dioxide D nitrogen oxides and methane

10 6092/01/Prelim/25 21 The reaction between zinc and hydrochloric acid is as follows. Zn(s) + 2HCl(aq) → ZnCl2(aq) + H2(g) The experiment is repeated with changes in the following conditions. 1 increase in concentration of the acid 2 increase in particle size of zinc 3 increase in pressure on the system 4 increase in temperature of the syst