SJI 2021 Y4 Prelim Chemistry 6092 P1

ST JOSEPH’S INSTITUTION PRELIMINARY EXAMINATION 2021 (YEAR 4) CANDIDATE NAME CLASS INDEX NUMBER CHEMISTRY Paper 1 Additional Materials : Multiple Choice Answer Sheet 6092/01 30 August 2021 1 hour (09:45 – 10:45) READ THESE INSTRUCTIONS FIRST Write your name, index number and class on the Answer Sheet in the spaces provided. Do not use staples, 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 or D. Choose the one you consider correct and record your choice in soft pencil on the 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 18 printed pages including this cover page.

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3 1 100 cm3 of carbon dioxide, CO2, diffused through a porous pot in 40 seconds. What would be the time taken for the same volume of ethene gas, C2H4, to diffuse? A 25 seconds B 35 seconds C 40 seconds D 55 seconds 2 The melting points and the boiling points of four substances are listed in the table below. substance melting point / °C boiling point / °C argon -189 -186 bromine -7 59 chlorine -101 -35 sulfur dioxide -75 -10 Which substance exists as a liquid at -90 °C? A argon B bromine C chlorine D sulfur dioxide 3 The solubility curves of three sa lts are shown below. Which salts can be prepared by crystallisation? A W only B Y only C W and X only D X and Y only solubility per 100g of water Salt W Salt X Salt Y temperature / °C

4 4 The diagram below shows the chromatogram of four substances, W, X, Y and Z. Which of the following statements is correct? A W contains X and Y. B X is more soluble than Z. C Y contains three components. D Z has a larger Rf value than X. 5 A particle of an isotope of sulfur contains 18 neutrons and 18 electrons. What is the symbol for this particle? A 𝑆16 34 2+ B 𝑆16 34 2- C 𝑆16 36 D 𝑆18 36

5 6 The diagram below shows the valence electrons of element W when combined with element X. Which of the following statements is incorrect, given that W is found in period 3 of the Periodic Table? A The oxide of W dissolves in water to form a solution which has pH ˃7. B W can react with lithium to form an ionic compound. C W cannot conduct electricity in any state. D W is a solid at room temperature. 7 How do the atomic radii and the intermolecular forces of attraction vary going down Group VII? atomic radius strength of intermolecular forces of attraction A decrease decrease B decrease increase C increase decrease D increase increase

6 8 The structure of two different substances are shown below. substance E substance F Which option provides the most appropriate description of the two substances? substance E substance F A covalent bonds present ionic bonds present B intermolecular forces not present intermolecular forces present C simple molecular structure giant molecular structure D stronger intermolecular forces weaker intermolecular forces 9 Substances X, Y and Z are all solids. Some of their physical properties are given in the table. substance X Y Z melting point / oC 772 114 1610 boiling point / oC 1407 183 2205 electrical conductivity in the liquid state conducts does not conduct does not conduct What type of structure does each substance have? X Y Z A giant molecular simple molecular ionic B ionic giant molecular simple molecular C ionic simple molecular giant molecular D simple molecular ionic giant molecular

7 10 When a piece of calcium carbonate is placed in an excess of sulfuric acid, a few bubbles of carbon dioxide are seen and then the reaction appears to stop. What is the best explanation for this observation? A Calcium carbonate is insoluble in water so it is unable to react with the acid. B Calcium sulfate is produced which is insoluble and prevents the acid from reaching the calcium carbonate. C The initial reaction is so fast that the acid is used up very quickly. D The reaction is endothermic and seems to stop when it cools down. 11 Different indicators change colour over different pH ranges and it is important to choose the correct indicator to obtain an accurate result in a titration. indicator pH range for the colour change colour lower pH higher pH indigo carmine 11.6 to 14.0 blue yellow methyl red 4.2 to 6.3 red yellow methyl violet 0.3 to 3.0 yellow violet phenolphthalein 8.2 to 10.0 colourless pink If a weak alkali is added to a strong acid, the following titration curve is obtained. Which of the indicators below would be the best choice to use in the titration? A indigo carmine B methyl red C methyl violet D phenolphthalein pH volume of weak alkali added in cm3

8 12 What is the best method to prepare pure silver chloride? A add aqueous silver nitrate to dilute hydrochloric acid B add aqueous silver nitrate to lead(II) chloride C add silver oxide to dilute hydrochloric acid D add silver to dilute hydrochloric acid 13 Which is the best method to obtain crystals of a pure soluble salt from dilute sulfuric acid? A add excess aqueous barium nitrate , filter the mixture , rinse and dry the residue B add excess aqueous sodium hydroxide, filter the mixture, heat the filtrate to saturation C add excess copper(II) carbonate, filter the mixture, heat the filtrate to dryness D add excess zinc oxide, filter the mixture, heat the filtrate to saturation 14 A solution of compound T forms a white precipitate which is soluble in excess aqueous ammonia. Upon adding acidified silver nitrate solution, a white precipitate is formed. What is compound T? A aluminium chloride B aluminium sulfate C zinc chloride D zinc sulfate 15 A white solid P produces a colourless gas Q on heating. Gas Q forms a white precipitate with aqueous calcium hydroxide. Which of the following could solid P be? A aluminium sulfate B calcium chloride C potassium carbonate D zinc carbonate

9 16 A green solution Z turns yellow on addition of aqueous acidified potassium manganate(VII) solution. Addition of excess aqueous sodium hydroxide to the resulting solution causes a reddish brown precipitate to form. When aluminium foil is added to the resulting mixture and warmed, a gas is evolved which turns moist red litmus blue. What is the identity of Z? A ammonium iodide B iron(II) iodide C iron(II) nitrate D iron(III) nitrate 17 Which statement about the Haber Process is correct? A Hydrogen is obtained from fractional distillation of liquid air. B Nitrogen is recycled to increase the yield of ammonia. C The Haber Process is favoured by low pressure. D The Haber Process is favoured by high temperature. 18 Which method cannot reduce the amount of pollutant gases that cause acid rain? A burn fuels with less than 2% sulfur content B pass exhaust gases through catalytic converters in motor vehicles C reduce usage of air-conditioners and refrigerants D use limestone to absorb pollutant gases from factories 19 The pollutants released into the air from car exhausts and some power stations