1. 2000-CE CHEMHONG KONG EXAMINATIONS AUTHORITY2 HONG KONG CERTIFICATE OF EDUCATION EXAMINATION 2000 CHEMISTRY PAPER 210.45 am 11.45 am(1 hour) Subject Code 160 1.Read carefully the instructions on the Answer Sheet and insert the information required (including the Subject Code) in the spaces provided.2.When told to open this book, check that all the questions are there. Look for the words END OF PAPER after the last question.ANSWER ALL QUESTIONS. 3. All the answers should be marked on the Answer Sheet.Note that you may only mark ONE answer to each question. 4. Two or more answers will score NO MARKS.5.All questions carry equal marks. No marks will be deducted for wrong answers. Hong Kong Examinations Authority All Rights Reserved 2000 2000-CE-CHEM 21

2. There are 50 questions in this paper. 1.A compound formed from element X and sulphur has the following electronic structure :S S X(Only electrons in the outermost shells are shown.)How many electrons are there in the outermost shell of an atom of X ? A. 2B. 4C. 6D. 8 2.Caesium (Cs) is a Group I element in the Periodic Table and its relative atomic mass is greater than that of potassium. Which of the following statements concerning caesium is INCORRECT ? A. Caesium is a weaker reducing agent than potassium.B. Caesium reacts violently with water.C. Caesium is a soft metal.D. Caesium reacts with oxygen to form an oxide with formula Cs2O. 3.Iron cans used for canning food are usually coated with tin instead of zinc. This is because A. tin is more reactive than zinc.B. tin ions are non-toxic but zinc ions are toxic.C. tin forms an alloy with iron and this alloy is corrosion resistant.D. tin prevents iron cans from rusting by sacrificial protection. 2000-CE-CHEM 221 All Rights Reserved 2000 3. 4. Metal X forms an oxide. 27.53 g of this oxide contains 24.96 g of X. Whatis the mole ratio of X to oxygen in the oxide ? (Relative atomic masses : O = 16.0, X = 207.0)A. 1:1 B. 1:2 C. 2:3 D. 3:4 5. Which of the following gases are the major products liberated in theelectrolysis of concentrated sodium chloride solution using carbonelectrodes ? CathodeAnodeA. hydrogen chlorine B. chlorine hydrogen C. hydrogen oxygen D. oxygen hydrogen 6. Which of the following pairs of compounds can be distinguished by treatingwith an acidified potassium dichromate solution ?A. ethane and ethene B. ethanol and propan-1-ol C. sodium carbonate and sodium hydrogencarbonate D. sodium sulphite and sodium sulphateElement X occurs in nature as two isotopes, 63X and 65X. If the relative 7.atomic mass of X is 63.5, what is the relative abundance of the 63X isotope ?A. 25% B. 60% C. 75% D. 90%Go on to the next page 2000-CE-CHEM 232 All Rights Reserved 2000 4. 8. Which of the following statements concerning members of a homologousseries is INCORRECT ? A.They contain carbon and hydrogen only.B.They can be represented by the same general formula.C.They have similar chemical properties.D.Their boiling points increase with their relative molecularmasses. 9. The atomic number of element X is 12. X reacts with element Y to forman ionic compound with formula XY2. To which group of the PeriodicTable does Y belong ? A.Group IB.Group IVC.Group VID.Group VII 10.Manufacturing ammonia by the Haber process involves the reversiblereaction : N2(g) + 3H2(g)2NH3(g) Which of thefollowing statements concerningthe process isINCORRECT ? A.The forward reaction can go to completion if iron powderis used as a catalyst.B.The optimum conditions for the process are 500C and200 atm.C.The raw materials are derived from air and water.D.The forward reaction and backward reaction occursimultaneously. 2000-CE-CHEM 24 3 All Rights Reserved 2000 5. 11.Different volumes of 2.0 M potassium hydroxide solution and 2.0 Msulphuric acid are mixed in a polystyrene cup. In which of the followingcombinations would the temperature rise be the greatest ?Volume of 2.0 M KOH(aq)/cm 3 Volume of 2.0 M H 2 SO 4 (aq)/cm 3 A.20.0 40.0B.30.0 30.0C.40.0 20.0D.45.0 15.0 12.Which of the following natural substances is essentially a singlecompound ?A. air B. coal C. petroleum D. quartz 13.Consider the compounds represented by the two structures below :OHH HHOand H CO C C H HC CC OHHH HH Which of the following statements concerning these compounds is correct ?A. Both compounds can turn wet blue litmus paper red. B. Both compounds have the same odour. C. Both compounds have the same molecular formula. D. Both compounds have the same boiling point.Go on to the next page 2000-CE-CHEM 25 4 All Rights Reserved 2000 6. 14.Which of the following solutions can react with bromine water to give acolourless solution ? A. sodium chloride solutionB. sodium sulphite solutionC. sodium iodide solutionD. sodium hypochlorite solution15.A polymer has the following structure : CH3 CH3C Cn H H What is the monomer of this polymer ? A. butaneB. but-1-eneC. but-2-eneD. 2-methylpropene16.Consider the following equation :3Zn(s) + 2NO3(aq) + 8H+(aq) 3Zn2+(x) + 2NO(y) + 4H2O(z) Which of the following combinations is correct ?y xzA. aqgaqB. aqgC. aqaqD. gaq The melting point and boiling point of substance X are 321C and 765C 17. In its molten state, X conducts electricity withoutrespectively.decomposition. X probably has A. an ionic structure.B. a metallic structure.C. a simple molecular structure.D. a covalent network structure. 2000-CE-CHEM 26 5 All Rights Reserved 2000 7. 18.Some potassium carbonate solution is added to a sample of tap water. Themixture then appears cloudy. Which of the following ions is probablypresent in the sample ? NH4+ A.Mg2+ B.Br C.SO42 D. 19.Gold ornaments are usually made from an alloy of gold and copper insteadof pure gold. This is because the alloyA.can be found free in nature. B.is more corrosion resistant than pure gold. C.is denser than pure gold. D.is stronger than pure gold.A sample of concentrated sulphuric acid has a density of 1.83 g cm3 and 20.contains 94.0% of sulphuric acid by mass. What is the concentration(correct to one decimal place) of sulphuric acid in the sample ? (Relative atomic masses : H = 1.0, O = 16.0, S = 32.1)A. 17.5 M B. 18.3 M C. 18.7 M D. 19.8 M 21.Which of the following processes requires a catalyst ?A. preparation of ethyl ethanoate from ethanoic acid andethanol B. conversion of sulphur trioxide to concentrated sulphuricacid C. manufacture of chlorine bleach from brine D. reduction of iron(III) oxide to iron Go on to the next page 2000-CE-CHEM 276 All Rights Reserved 2000 8. 22.A white solid dissolves in water to give an alkaline solution. The solutionreacts with dilute hydrochloric acid to give a gas. The solid is probablyA. calcium oxide. B. calcium carbonate. C. potassium hydroxide. D. potassium carbonate.In an experiment, 21.8 g of zinc was treated with 250.0 cm3 o f 2 M 23. .0hydrochloric acid. What volume of hydrogen was liberated at roomtemperature and pressure ? (Relative atomic mass : Zn = 65.4; 3 molar volume of gas at room temperature and pressure = 24.0 dm ) 4.0 dm3 A.6.0 dm3 B.8.0 dm3 C. 12.0 d m3 D. 24.Which of the following compounds is insoluble in water ?A. methanol B. methanoic acid C. methyl methanoate D. sodium methanoate (This item was deleted.)25.Which of the following processes is endothermic ?A. cracking of petroleum fractions B. fermentation of glucose solution C. manufacture of ammonia by the Haber process D. oxidation of sulphur dioxide to sulphur trioxide in thecontact process 2000-CE-CHEM 28 7 All Rights Reserved 2000 9. 26.Which of the following combinations is correct ? Type of fireType of fire extinguisher to useA. electrical fire water B. electrical fire foam C. kerosene fire water D. kerosene fire foam 27.Which of the following changes occurs in a catalytic converter installed in amotor car ?A. Nitrogen monoxide changes to nitrogen dioxide. B. Carbon monoxide changes to carbon dioxide. C. Unburnt hydrocarbons change to carbon particles. D. Sulphur changes to sulphur dioxide. 28.Which of the following changes is NOT a redox reaction ? Fe2(SO4)3 + H2S 2FeSO4 + S + H2SO4 A.2Al + 6HCl 2AlCl3 + 3H2 B.CaCO3 + CO2 + H2O Ca(HCO3)2 C.2KClO3 2KCl + 3O2 D. 29.Which of the following compounds would react with ammonium chlorideon heating ?A. concentrated nitric acid B. concentrated hydrochloric acid C. sodium hydroxide solution D. magnesium sulphate solutionGo on to the next page 2000-CE-CHEM 298 All Rights Reserved 2000 10. 30.In which of the following substances does nitrogen has the smallestoxidation number ?A. NH3 B. NO C. N2O D. N231.Which of the following uses of sulphuric acid is/are correct ? (1)manufacture of soaps(2)manufacture of paint additives(3)manufacture of fertilizersA. (1) only B. (2) only C. (1) and (3) only D. (2) and (3) only32.Which of the following articles should be made from thermosettingplastics ? (1)wall paper(2)television casing(3)water bucketA. (1) only B. (2) only C. (1) and (3) only D. (2) and (3) only33.In an experiment, a piece of calcium metal was added to a beaker of water.Which of the following statements concerning the experiment is/arecorrect ? (1)The calcium metal sank to the bottom of the beaker.(2)The calcium metal burnt with a brick red flame.(3)At the end of the experiment, an alkaline solution was formed in the beaker.A. (1) only B. (2) only C. (1) and (3) only D. (2) and (3) only2000-CE-CHEM 210 9 All Rights Reserved 2000 11. 34.Which of the following statements concerning helium is/are correct ? (1)The outermost electron shell of a helium atom has an octet structure.(2)Helium is used to fill weather balloons.(3)Helium exists as monatomic molecules.A. (1) only B. (2) only C. (1) and (3) only D. (2) and (3) only 35.Consider the chemical cell shown below : salt bridgemagnesiumcopper 1M magnesium1M copper(II) sulphate solutionsulphate solution Beaker XBeaker YWhich of the following statements concerning the cell is/are correct ? (1)Oxidation takes place at the copper electrode. The concentration of magnesium ions in beaker X increases.(2)(3)The salt bridge allows electrons to flow from one electrode to the other electrode.A. (1) only B. (2) only C. (1) and (3) only D. (2) and (3) onlyGo on to the next page 2000-CE-CHEM 211 10 All Rights Reserved 2000 12. 36.Which of the following polymers is/are made by condensationpolymerization ?O OH H(1)C (CH2)4CN(CH2)6 Nn OC OCH3 (2)CH2 Cn CH3F F(3)C C n F FA. (1) onlyB. (2) onlyC. (1) and (3) onlyD. (2) and (3) only37.Which of the following statements concerning drugs is/are correct ? (1) Morphine is an effective painkiller.(2) Acetaminophen (paracetamol) can damage the stomach lining.(3) A suspension of milk of magnesia in water has a pH greater than 7. A. (1) onlyB. (2) onlyC. (1) and (3) onlyD. (2) and (3) only 2000-CE-CHEM 212 11 All Rights Reserved 2000 13. 38. sink catchpotSome concentrated sulphuric acid was poured into a sink connected to acatchpot made of polyvinyl chloride (PVC). After some time, the catchpotbecame deformed.Which of the following explanations for thedeformation of the catchpot is/are correct ? (1) The heat liberated when the concentrated sulphuric acid mixed withthe water in the catchpot caused PVC to soften.(2) PVC was decomposed into its monomers by the concentratedsulphuric acid.(3) PVC was oxidized by the concentrated sulphuric acid. A.(1) onlyB.(2) onlyC.(1) and (3) onlyD.(2) and (3) only Go on to the next page 2000-CE-CHEM 213 12 All Rights Reserved 2000 14. X can form X2 ions. 39.X is an element in Group VI of the Periodic Table.Which of the following statements are correct ? The oxidation number of X decreases when X2 ion is formed.(1)Both X atom and X2 ion have the same number of electron shells.(2)Both X atom and X2 ion have the same nuclear charge.(3) A. (1) and (2) onlyB. (1) and (3) onlyC. (2) and (3) onlyD. (1), (2) and (3) 40.Which of the following measures can reduce the emission of pollutants froma coal-fired power station ? (1) installation of scrubbers(2) installation of electrostatic precipitators(3) increasing the height of the chimney A. (1) and (2) onlyB. (1) and (3) onlyC. (2) and (3) onlyD. (1), (2) and (3)41.Which of the following statements concerning soaps are correct ? (1) They are esters.(2) They can reduce the surface tension of water.(3) Their aqueous solutions are alkaline. A. (1) and (2) onlyB. (1) and (3) onlyC. (2) and (3) onlyD. (1), (2) and (3) 2000-CE-CHEM 214 13 All Rights Reserved 2000 15. 42.Which of the following statements concerning carbon, silicon andphosphorus are correct ? (1) Carbon forms numerous compounds with hydrogen and oxygen.(2) Silicon is used to make computer chips.(3) Phosphorus is an essential element for plant growth. A. (1) and (2) onlyB. (1) and (3) onlyC. (2) and (3) onlyD. (1), (2) and (3)43.Which of the following statements concerning a zinc-carbon cell are correct ? (1) The ammonium chloride in the cell acts as an electrolyte.(2) The manganese(IV) oxide in the cell acts as an oxidizing agent.(3) The zinc case of the cell acts as the positive terminal. A. (1) and (2) onlyB. (1) and (3) onlyC. (2) and (3) onlyD. (1), (2) and (3) 44.Which of the following statements concerning sulphur dioxide are correct ? (1) It can be prepared by heating copper turnings with concentratedsulphuric acid.(2) It is denser than air.(3) It can be absorbed by sodium hydroxide solution. A. (1) and (2) onlyB. (1) and (3) onlyC. (2) and (3) onlyD. (1), (2) and (3) Go on to the next page 2000-CE-CHEM 215 14 All Rights Reserved 2000 16. Directions : Each question below (Question Nos. 45 to 50) consists of twoseparate statements. Decide whether each of the two statements istrue or false; if both are true, then decide whether or not the secondstatement is a correct explanation of the first statement. Then selectone option from A to D according to the following table :A. Both statements are true and the 2nd statement is a correct explanation of the1st statement. B. Both statements are true but the 2nd statement is NOT a correct explanation ofthe 1st statement. C. The 1st statement is false but the 2nd statement is true. D. Both statements are false.1st statement 2nd statement45. Concentrated sulphuric acid canConcentrated sulphuric acid is a turn a piece of filter paper black.strong oxidizing agent.46. Carbon dioxide and silicon dioxide The atoms of carbon and silicon have similar physical properties.have the same number of electronsin their outermost shells.47. Chlorine is a better bleaching agent Chlorine bleaches by reduction. for silk than sulphur dioxide.48. The volume of 10.0 g of gaseous10.0 g of gaseous carbon dioxide carbon dioxide is the same as thecontains the same number of volume of 10.0 g of solid carbon molecules as 10.0 g of solid carbon dioxide. dioxide.49. Adding lime to acidic soil can Lime can neutralize the acid in the increase crop yield. soil.50. Aluminium was used earlier thanAluminium is more abundant than iron in the history of mankind.iron in the earth crust.END OF PAPER 2000-CE-CHEM 216 15 All Rights Reserved 2000 17. 2000 Chemistry Paper 2Question No.Key Question No. Key 1.B 26.D2.A 27.B3.B 28.C4.D 29.C5.A 30.A 6.D 31.D7.C 32.B8.A 33.C9.D 34.D10. A 35.B 11. C 36.A12. D 37.C13. C 38.A14. B 39.D15. C 40.A 16. B 41.C17. B 42.D18. B 43.A19. D 44.D20. A 45.B 21. A 46.C22. D 47.D23. B 48.C 18. 24. 49.A25. A 50.C All Rights Reserved 2000