Zhonghua Prelim P1

1 [Turn over ZHONGHUA SECONDARY SCHOOL PRELIMINARY EXAMINATION 2024 SECONDARY 4 EXPRESS Candidate’s Name Class Register Number CHEMISTRY 6092 /01 Paper 1 21 August 2024 1 hour Additional Materials: OTAS READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, highlighters, glue or correction fluid. Write your name, index number and class on the OTAS 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 and D. Choose the one you consider correct and record your choice in soft pencil on the separate OTAS. Read the instructions on the OTAS 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 20. The use of an approved scientific calculator is expected, where appropriate. This document consists of 19 printed pages and 1 blank page.

2 1 The following set-up was used to obtain a sample of carbon monoxide in the laboratory. The sample of carbon monoxide collected is found to be an impure mixture of two gases. How can a pure sample of carbon monoxide be obtained? A bubble the stream of gas from X into a flask containing aqueous sodium hydroxide before collection B bubble the stream of gas from X into a flask containing concentrated sulfuric acid before collection C use concentrated sulfuric acid instead of dilute hydrochloric acid for the reaction with calcium carbonate D use larger pieces of charcoal 2 Three separations are listed. 1 obtaining ethanol from a mixture of water and ethanol 2 obtaining water from a mixture of oil and water 3 obtaining water from calcium chloride solution Which techniques would be involved in these separations? 1 2 3 A evaporation simple distillation simple distillation B fractional distillation use of a separation funnel evaporation C fractional distillation use of a separation funnel simple distillation D simple distillation filtration fractional distillation dilute hydrochloric acid charcoal X carbon monoxide heat calcium carbonate gas jar water

3 [Turn over 3 The apparatus below is set up, using different gases in the two inverted beakers. Which pair of gases would cause an upward movement of the water level at U? gas 1 gas 2 A helium carbon dioxide B nitrogen carbon monoxide C nitrogen hydrogen D oxygen hydrogen 4 A gaseous mixture is made up of argon, chlorine and nitrogen. Which diagram shows a pure sample of this mixture? A B C D

4 5 The formulae of four covalent molecules are shown. 1 CH3CH2OH 2 CH3COOH 3 H 2O 4 O 2 In which pair of molecules does oxygen form at least one double bond in both molecules? A 1 and 2 B 2 and 3 C 2 and 4 D 3 and 4 6 Formation of metallic oxides requires electrons to be transferred from metal atoms to oxygen atoms. In the formation of one mole of metallic oxide, which oxide does not involve the metal atoms transferring exactly two moles of electrons? A aluminium oxide B calcium oxide C copper(II) oxide D potassium oxide 7 In an experiment, aqueous barium nitrate, molten calcium chloride, solid graphite and solid iron metal are found to be able to conduct electricity. Which pair of substances conduct electricity utilising mobile electrons? A aqueous barium nitrate and molten calcium chloride B molten calcium chloride and solid graphite C molten calcium chloride and solid iron metal D solid graphite and solid iron metal

5 [Turn over 8 In which molecule are all the valence electrons in the atoms involved in bonding? A ammonia B butene C carbon dioxide D nitrogen 9 The table shows four elements P, Q, R and S with their atomic numbers. element P Q R S atomic number 6 12 13 8 What are the likely formulae of a ionic compound and a covalent compound formed from P, Q, R and S? formula of ionic compound formula of covalent compound A QS2 Q 2P B Q3R2 R 2S3 C R2S3 PS 2 D S2 Q 2P 10 An element X has two isotopes, which can be represented as 239X and 243X. How does 243X differ from 239X? A It has 4 more electrons and has a higher melting point. B It has 4 more neutrons and has a higher density. C It has 4 more neutrons and is more reactive. D It has 4 more protons and is more reactive.

6 11 Graphite can be used as a dry lubricant, with the advantage of not leaving sticky residues. Powdered graphite can be use in a lock to allow the key to turn more easily. Which statement best describe the structure of graphite that allows it to be used as a lubricant? A Each carbon atom has four bonds and can form an unreactive film over which the metal can slide. B The bonds between the carbon atoms are weak and the carbon atoms can easily slide over one another. C The carbon atoms are bonded with weak intermolecular forces of attraction between layers, which can slide freely over one another. D The tetrahedral arrangement of bonds around each carbon atom causes the neighboring atom to slide past one another easily. 12 When potassium iodide is added to silver nitrate, a yellow precipitate is formed. The chemical reaction is represented in the chemical equation below. KI(aq) + AgNO3(aq)  KNO3(aq) + AgI(s) 50.0 cm3 of potassium iodide solution was added to 0.600 mol/dm3 silver nitrate solution. The height of the precipitate formed was plotted to give the graph shown below. What is the concentration of the potassium iodide solution? A 0.6 mol/dm3 B 1.2 mol/dm3 C 60 mol/dm3 D 100 mol/dm3

7 [Turn over 13 2.50 g of an impure sample of a metal carbonate, MCO3, was heated strongly in a crucible until its mass remains constant. At the end of the experiment, 0.48 dm3 of carbon dioxide was produced and 1.12 g of pure oxide remained in the crucible. The decomposition of the metal carbonate is shown by the equation below: MCO3 (s) → MO (s) + CO2 (g) What is the relative atomic mass of M? A 1.12÷0.48 24 B 1.12÷0.48 24 −16 C 2.50÷0.48 24 D 2.50÷0.48 24 −60 14 Which fuel produces 144 dm3 of carbon dioxide upon complete combustion? A 0.5 mol of C6H12 B 1.5 mol of C4H8 C 3.0 mol of C3H7OH D 6.0 mol of C2H6 15 Bromine can be extracted from a solution of calcium bromide. What is the mass of bromine that can be extracted from 100 g of a calcium bromide solution that is 36% by mass? A 28.8 g B 36.0 g C 57.6 g D 72.0 g

8 16 Butyne, C4H6, reacts with oxygen as shown in the equation below. 2C4H6 (g) + 11O2 (g) → 8CO2 (g) + 6H2O (l) In an experiment, 100 cm3 of butyne, reacts with 660 cm3 of oxygen at r.t.p. What is the total volume of gas remaining at the end of the reaction? A 110 cm3 B 400 cm3 C 510 cm3 D 810 cm3 17 Which two reactants will react to give products that contains two salts? A aqueous potassium hydroxide and aqueous ammonium nitrate B aqueous sodium chloride and aqueous silver nitrate C dilute hydrochloric acid and iron D dilute nitric acid and solid calcium carbonate 18 Nitrogen is needed for production of amino acids in plants and thus nitrogenous fertilisers such as ammonium nitrate is used to increase crop yield by increasing nitrogen content in the soil. In a region suffering from acid rain, which substance can be added to control the pH of the soil in a farm using ammonium nitrate as fertiliser without causing a loss of nitrogen? A calcium carbonate B calcium hydroxide C magnesium hydroxide D sodium hydroxide

9 [Turn over 19 A few drops of Universal Indicator are added to solutions X and Y and the results are shown below. solution Universal Indicator X red Y yellow Which con