2022 ZSS Chem Prelims P1

Paper 1 Multiple Choice 13 September 2021 1 hour Additional Materials: Multiple Choice Answer Sheet Zhenghua Secondary School Zhenghua Secondary School Zhenghua Secondary School Zhenghua Secondary School Zhenghua Secondary School Zhenghua Secondary School Zhenghua Secondary School Zhenghua Secondary School Zhenghua Secondary School Zhenghua Secondary School Zhenghua Secondary School Zheng hua Secondary School Zhenghua Secondary School Zhenghua Secondary School Zhenghua Secondary School Zhenghua Secondary School Zhenghua Secondary School Zhenghua Secondary School Zhenghua Secondary School Zhenghua Secondary School READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, glue or correction fluid. Write your name, Centre number 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. Name of Setter: Ms Nur Elfianie Abdul Samad This document consists of 19 printed pages including this cover page. [Turn over ZHENGHUA SECONDARY SCHOOL PRELIMINARY EXAMINATION 2022 SECONDARY FOUR EXPRESS CHEMISTRY 6092/01 Candidate Name: _____________________________ Index No: _____ Class: _________

2 1 Th rate of diffusion of five gases is measured. The gases are CO, CO 2, NH3, C3H8 and N2., The list gives five pairs of gases. 1 CO and CO2 2 CO and N2 3 CO2 and C3H8 4 NH3 and N2 5 NH3 and CO In which pairs would one gas diffuse faster than the other under the same conditions of temperature and pressure? A 1 and 4 B 2 and 3 C 2, 3 and 5 D 1, 4 and 5 2 The boiling points of some substances found in air are given in the table. When the temperature is raised from -350○C to -190○C, which substance(s) will be liquid? substance boiling point / ○C argon -186 neon -246 oxygen -196 nitrogen -183 A argon only B argon and oxygen C neon and nitrogen D neon and oxygen

3 3 A gas has no effect on both red and blue litmus papers but is soluble in water and less dense than air. Which diagram shows the best way of drying and collecting the gas? A B C D 4 An aqueous solution of a salt is tested and the following results are obtained. test result addition of a few drops of aqueous sodium hydroxide followed by addition of excess aqueous sodium hydroxide white precipitate forms, then dissolves addition of 2 cm3 of dilute sulfuric acid effervescences, gas turned blue litmus paper red What ions are most likely found in the salt? A Al3+ and SO42- B Al3+, Zn 2+ and CO32- C Al3+, Zn2+ and SO42- D Zn2+ and CO32-

4 5 Element R has p protons and n neutrons in its neuclues. Which row gives the correct number of sub-atomic particles in a negative ion of an isotope of R? proton neutron electron A p n + 1 p + 1 B p n - 1 p - 1 C p + 1 n p + 1 D p + 1 n p - 1 6 Which statement(s) correctly describes the properties of mixtures of iron and sulfur and the compound iron(II) sulfide? mixtures of iron and sulfur compound iron(II) sulfide 1 iron and sulfur mixed without undergoing a chemical reaction iron and sulfur combined in a chemical reaction 2 the ratio of iron and sulfur varies the ratio of iron and sulfur is always the same 3 properties of iron and sulfur were lost when the mixture was formed. iron(II) sulfide has the same properties of iron and sulfur A 1 only B 1 and 2 C 2 and 3 D 3 only

5 7 The following all conduct electricity. 1 aqueous copper(II) sulfate 2 copper metal 3 molten sodium chloride 4 solid graphite Which substance(s) conduct/s electricity using free-moving electrons? A 1 and 2 B 2 and 3 C 2 and 4 D 3 and 4 8 The diagram shows a structure of a compound made of carbon and silicon atoms, (SiC)n. Which statement is true for (SiC)n? key ○ atom of silicon ● atom of carbon A It acts as a lubricant. B It conducts electricity. C It is a gas at room temperature. D It is insoluble in water. 9 22 g of hydrocarbon X has a volume of 12 dm 3 at room temperature and pressure. What is the molecular formula of X? A CH4 B C2H6 C C3H6 D C3H8 10 Which statement about electrolysis is correct?

6 A Chemical energy is converted to electrical energy. B Electrons flow through the electrolyte. C Ionic compounds are broken down. D Metals are formed at the positive electrode. 11 The diagram below shows the apparatus used to electroplate a metal ring with lead. The electroplating was not successful. What change must be made for it to work? A Add solid lead(II) sulfate to the electrolyte. B Increase the temperature of the electrolyte. C Replace the lead electrode with carbon electrode. D Reverse the terminals of the battery. battery metal ring lead electrode aqueous lead(II) nitrate

7 12 The complete combustion of ethane is an exothermic reaction. Which statement explains this? A More bonds are broken than formed. B More bonds are formed than broken. C The total enthalpy of the bonds broken is greater than the total enthalpy of the bonds formed. D The total enthalpy of the bonds broken is less than the total enthalpy of the bonds formed. 13 An equation for respiration is shown. C6H12O6 + 6O2 → 6H2O + 6CO2 ∆H = - 2830 kJ/mol What can be deduced from this equation? A Energy form the sun is needed for this reaction. B Glucose is reduced. C Larger molecules are made from smaller molecules. D ∆H for photosynthesis is +2830 kJ/mol

8 14 The energy profile diagram for a given reaction without the use of catalyst is shown below. Which energy profile diagram is correct for the same reaction but using a catalyst? A B C D

9 15 Excess calcium carbonate was reacted with 25.0 cm 3 of 2 mol/dm 3 of dilute hydrochloric acid at 50○C. The gas produced was collected at regular time and the results are shown below as experiment 1. Similarly, experiment 2 was a reaction between excess calcium carbonate and dilute hydrochloric acid but the volume of gas collected in experiment 1 was twice of that in experiment 2. What change was made to produce the graph of experiment 2? A Add catalyst. B Reduce the concentration of dilute hydrochloric acid to 1 mol/dm3 C Reduce the temperature of the reaction to 25○C. D Reduce the volume of dilute hydrochloric acid to 12.5 cm3 16 The following reactions take place during a thunderstorm. N2 + O2 → 2NO 2NO + O2 → 2NO2 NO + O2 → NO2 + O2 Which row shows the correct processes undergo by the reactants? N2 NO O3 A oxidised oxidised oxidised B oxidised oxidised reduced C reduced reduced oxidised experiment 1 experiment 2 time / s volume of gas produced / cm3

10 D reduced reduced reduced 17 The dissociation constant for an acid indicates the extent of dissociation into its ions. The higher the dissociation constant, the stronger the acid. The dissociation constants of some acid and two statements are given below. acid dissociation constant methanoic acid, HCO2H 1.80 x 10-4 ethanoic acid, CH3CO2H 1.75 x 10-5 proponoic acid, CH3CH2CO2H 1.34 x 10-5 chloroethanoic