SJI 2024 Y4 Prelim Chemistry Paper 1

1 ST. JOSEPH’S INSTITUTION PRELIMINARY EXAMINATION 2024 (YEAR 4) CANDIDATE NAME CLASS INDEX NUMBER CHEMISTRY Paper 1 Additional Materials: Multiple Choice Answer Sheet 6092/01 26 August 2024 1 hour (08:05 – 09:05) READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, glue or correction fluid. Write your name, index number and class 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 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 Question paper. A copy of the Periodic Table is printed on page 2 of this question paper. The use of an approved scientific calculator is expected, where appropriate. This document consists of 22 printed pages.

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3 1 The diagram shows the apparatus used to prepare a liquid compound L. Compound L (boiling point 57 °C) is made by heating together two liquids, M (boiling point 78 °C) and N (boiling point 95 °C). The reaction is slow. What is the purpose of the condenser? A to allow liquid L to escape as fast as it is formed B to enable M and N to mix more efficiently C to keep air away from the reacting liquids D to prevent M and N from escaping before the reaction is complete heat cold water M + N

4 2 A student plans two experiments. In experiment 1, he wants to determine the concentration of an aqueous solution of sodium hydroxide by reacting it with dilute hydrochloric acid. In experiment 2, he wants to investigate the rate of the reaction between calcium carbonate and dilute nitric acid by measuring the volume of gas produced at regular intervals. The student is provided with conical flasks for the experiments. What additional apparatus is needed? experiment 1 experiment 2 A burette, pipette balance, gas syringe B burette, pipette gas syringe, stopwatch C gas syringe, stopwatch burette, pipette D measuring cylinder, thermometer gas syringe, stopwatch 3 The apparatus below can be used to show the diffusion of gases. Which pair of gases in the porous pot will cause the water level at Z to rise after some time? A chlorine and krypton B ethene and methane C helium and nitrogen D hydrogen and propene carbon dioxide mixture of two gases Z porous pot

5 4 What is the number of electrons and neutrons in a hydroxide ion? electrons neutrons A 9 8 B 9 9 C 10 8 D 10 9 5 Calcium and iodine react together to form a compound. Which statement describes this reaction? A Each calcium atom gains one electron and each iodine atom gains one electron. B Each calcium atom loses one electron and each iodine atom loses one electron. C Each calcium atom loses two electrons and each iodine atom gains one electron. D Each calcium atom loses two electrons and each iodine atom gains two electrons. 6 Which statements about calcium chloride and potassium chloride are correct? 1 Calcium chloride has a higher melting point than potassium chloride as the calcium atom has a greater charge than the potassium atom. 2 In the calcium chloride lattice, the ratio of calcium ions to chloride ions is half that of the ratio of potassium ions to chloride ions in the potassium chloride lattice. 3 Molten calcium chloride has a greater electrical conductivity than molten potassium chloride as calcium contributes more electrons to the delocalised ‘sea of electrons’ than does potassium. A 2 only B 3 only C 1 and 2 only D 1 and 3 only

6 7 Which molecule has the largest number of electrons involved in bonding? A C2H4 B CO2 C CH3OH D N2 8 Which statement about metals is correct? A A giant metallic lattice consists of metal atoms in a ‘sea of electrons’. B All metals have high melting points. C Electrons in a metal move randomly through the giant metallic lattice. D Metals are malleable as the atoms in a metal are mobile. 9 At room temperature and pressure, carbon dioxide is a gas while silicon dioxide is a solid. Which statement explains this? A Attractive forces between carbon dioxide molecules are weaker than the attractive forces between ions in silicon dioxide. B Both substances have different covalent structures. C The covalent bonds in carbon dioxide are weaker than those in silicon dioxide. D There are less covalent bonds in carbon dioxide than in silicon dioxide.

7 10 The equations show the reactions involved in the formation of poly(ethene) from calcium carbide, CaC2. CaC2 + 2H2O → Ca(OH)2 + C2H2 C2H2 + H2 → C2H4 nC2H4 → (C2H4)n In the first reaction, 64 kg of calcium carbide is reacted with 54 kg of water. What is the maximum mass of poly(ethene) obtained? A 14 kg B 28 kg C 42 kg D 84 kg 11 6.0 cm 3 of a 0.5 mol/dm 3 solution of acid X exactly neutrali ses 22.50 cm 3 of 0.4 mol/dm3 aqueous potassium hydroxide. What is the formula of acid X? A C2H5COOH B HNO3 C H2SO4 D H3PO4 12 In an experiment, 41.4 g of potassium carbonate reacted with excess dilute hydrochloric acid to form 20.5 g of potassium chloride. What is the percentage yield of potassium chloride? A 45.9 % B 49.5 % C 65.9 % D 91.7 %

8 13 A pure fat has a relative molecular mass of 300. 150 g of the fat reacts with 240 g of bromine. What volume of hydrogen, measured at room temperature and pressure, is needed to fully convert 75 g of the fat into margarine? A 12 dm3 B 18 dm3 C 36 dm3 D 72 dm3 14 The table gives some statements about acids and bases and explanations for these statements. One of the substances below, hydrazine, has similar properties to ammonia, and the formula H2NNH2. Which row shows both a correct statement and a correct explanation for the statement? statement explanation A ammonia can be made by heating ammonium carbonate with calcium hydroxide the hydroxide ion gives H+ to the ammonium ion B hydrazine reacts with hydrogen chloride to form a compound with formula ClH3NNH3Cl hydrazine molecules remove H+ ions from hydrogen chloride C the pH of a weak acid is always higher than the pH of a strong acid pH shows the strength of acid – the stronger the acid, the lower the pH D when copper is added to dilute hydrochloric acid, copper is oxidised oxidation is loss of electrons

9 15 The diagram shows an experiment for the formation of gas X. What is gas X? A carbon dioxide B carbon monoxide C chlorine D hydrogen 16 Copper(II) nitrate is made by reacting an excess of a powdered solid with an aqueous solution. The mixture is filtered and the filtrate crystallised. Which row identifies a solid and an aqueous solution that can be used to make a pure sample of copper(II) nitrate? solid in excess aqueous solution A copper zinc nitrate B copper silver nitrate C copper(II) hydroxide sodium nitrate D copper(II) sulfate dilute nitric acid heat carbon X water aqueous sodium hydroxide marble chips (calcium carbonate) dilute hydrochloric acid

10 17 Which statement about the Haber process is correct? A Both gaseous reactants are obtained from fractional distillation of liquid air. B Finely-divided iron is used to increase the rate and yield of t