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S.5 Chemistry Summer Assignment (For ALL) CHEMISTRY PAPER 1 (2 hours 30 minutes) This paper must be answered in English. GENERAL INSTRUCTIONS 1 There are TWO sections, A and B, in this Paper. You are advised to finish Section A in about 45 minutes. 2 Section A consists of multiple-choice questions in this question book, while Section B contains conventional questions printed separately in Question-Answer Book B. 3 Answers to Section A should be marked on the Multiple-choice Answer Sheet while answers to Section B should be written in the spaces provided in Question-Answer Book B. The Answer Sheet for Section A and the Question-Answer Book for Section B will be collected separately at the end of the examination. 4 A Periodic Table is printed on page 26 of Question-Answer Book B. Atomic numbers and relative atomic masses of elements can be obtained from the Periodic Table. INSTRUCTIONS FOR SECTION A (MULTIPLE-CHOICE QUESTIONS) 1 Read carefully the instructions on the Answer Sheet. After the announcement of the start of the examination, you should first stick a barcode label and insert the information required in the spaces provided. No extra time will be given for sticking on the barcode label after the ‘Time is up’ announcement. 2 When told to open this book, you should check that all the questions are there. Look for the words ‘END OF SECTION A’ after the last question. 3 All questions carry equal marks. 4 ANSWER ALL QUESTIONS. You are advised to use an HB pencil to mark all the answers on the Answer Sheet so that wrong marks can be completely erased with a clean rubber. You must mark the answers clearly; otherwise you will lose marks if the answers cannot be captured. 5 You should mark only ONE answer for each question. If you mark more than one answer, you will receive NO MARKS for that question. 6 No marks will be deducted for wrong answers. Not to be taken away before the end of the examination session 1 SECTION A 1 The atomic number of element X is 33. Which of the following can represent the electron diagram of a chloride of X? (Only electrons in the outermost shells are shown.) A B C D 2 A colour moves towards the left in the above set-up. The coloured crystal on the filter paper could be 3 A. chromium(III) sulphate. B iron(III) chloride. C. potassium permanganate. D sodium sulphate. Which of the following combinations shows a correct matching of a molecule and its structural formula? A. B. C. D. Molecule Helium Nitrogen Hydrogen peroxide Sulphur dichloride Structural formula He=He N–N H–O–O–H Cl=S=Cl 2 4 The table below shows whether displacement reaction occurs between four metals and their ions. ‘’ represents that displacement reaction occurs, while ‘✘’ represents that displacement reaction does not occur. Which of the following is the strongest oxidizing agent? A. Cd2+(aq) 5 B. Ra2+(aq) C. Cd(s) D. Ra(s) Metal M forms an oxide. Complete reduction of a sample of this oxide by carbon produces 7.53 g of metal M and 3.96 g of carbon dioxide. What is the empirical formula of the oxide? (Relative atomic masses: M = 55.8) A. MO 6. B. M2O3 C. MO2 D. M3O4 The structure of ethanedioic acid is shown below. A 25.0 cm3 solution of ethanedioic acid reacts completely with 20.0 cm3 of 1.90 mol dm–3 NaOH(aq). What is the concentration of the ethanedioic acid? A. 0.760 mol dm–3 7 B. 1.33 mol dm–3 C. 1.52 mol dm–3 D. 2.38 mol dm–3 Which of the following statements about 0.1 mol dm–3 HCl(aq) and 0.1 mol dm–3 CH3COOH(aq) is correct? A The pH of 0.1 mol dm–3 CH3COOH(aq) is lower than that of 0.1 mol dm–3 HCl(aq). B 10 cm3 of 0.1 mol dm–3 HCl(aq) require a greater volume of 0.1 mol dm–3 NaOH(aq) for complete neutralization than 10 cm3 of 0.1 mol dm–3 CH3COOH(aq) do. C The electrical conductivity of 0.1 mol dm–3 CH3COOH(aq) is higher than that of 0.1 mol dm–3 HCl(aq). D When reacted with Mg(s), 0.1 mol dm–3 HCl(aq) gives the same volume of hydrogen as 0.1 mol dm–3 CH3COOH(aq). 3 8 Compound Q reacts with dilute sulphuric acid to give a colourless gas R and an aqueous solution S. When the solution S is further treated with sodium hydroxide solution, it does not give a precipitate. What could this compound be? (1) Sodium hydrogencarbonate (2) Copper(II) carbonate (3) Potassium sulphate A. (1) only 9 B. (2) only B. PI3 C. SF6 D. NCl5 What is the oxidation number of cobalt (Co) in K3[Co(NO2)6]? A. +2 11 D. (2) and (3) only Which of the following species does NOT exist? A. BH3 10 C. (1) and (3) only B. +3 C. +4 D. +6 The ionic half-equations for a redox reaction are shown below: 2I–(aq) I2(aq) + 2e– MnO4 (aq) + 8H+(aq) + 5e– Mn2+(aq) + 4H2O(l) – How many moles of iodide ions are oxidized by one mole of permanganate ions? A. 0.2 12 B. 0.4 C. 2 D. 5 The tendency of being reduced of five ionic species increases in the order as shown below: Mn2+(aq) < Zn2+(aq) < Ni2+(aq) < Pb2+(aq) < H+(aq) Which of the following statements is correct? 13 A Mn(s) does NOT react with H+(aq) ions. B Zn(s) has a stronger reducing power than Pb(s). C Ni2+(aq) ion is a stronger oxidizing agent than Pb2+(aq) ion. D A displacement reaction occurs when Pb(s) is immersed in ZnSO4(aq). 123 I and 127I are two isotopes of iodine. Which of the following statements about these two isotopes is / are correct? (1) 123 I is more reactive than 127I. (2) 123 I and 127I have the same number of electrons. (3) 127 I has a greater number of protons than 123I. A. (1) only B. (2) only C. (1) and (3) only D. (2) and (3) only 14. Which of the following methods can be used to distinguish between Na2CO3(aq) and ZnCl2(aq)? (1) Adding NH3(aq) (2) Performing a flame test (3) Adding HCl(aq) A. (1) and (2) only B. (1) and (3) only C. (2) and (3) only 4 D. (1), (2) and (3) 15. Consider the following reaction: 3N2O(g) + 2NH3(g) ΔHø = –880 kJ 4N2(g) + 3H2O(g) Given the following data: H of (kJ mol-1) -45.9 -242 Compound NH3(g) H2O(g) What is the standard enthalpy change of formation of N2O(g)? A. +246 kJ mol–1 B. +81.9 kJ mol–1 C. –81.9 kJ mol–1 D. –246 kJ mol–1 16 Which of the following compounds can be used as monomers to make addition polymers? (1) (2) A. (1) and (2) only 17 (3) B. (1) and (3) only C. (2) and (3) only D. (1), (2) and (3) Barium is a Group II element. A small piece of barium is dropped into a trough of water containing a few drops of methyl orange. Which of the following is / are the expected observation(s)? (1) A colourless gas is liberated. (2) The piece of barium moves about on the water surface with a hissing sound. (3) The resulting solution in the trough is red in colour. A. (1) only 18 B. (2) only C. (1) and (3) only D. (2) and (3) only Which of the following processes would give an obvious colour change? (1) Bubbling propene into acidified potassium permanganate solution (2) Adding bromine solution to potassium chloride solution (3) Adding calcium into dilute hydrochloric acid A. (1) only B. (2) only C. (1) and (3) only 5 D. (2) and (3) only 19 Isoamyl acetate is found naturally as the flavour and scent of bananas. CH3COOCH2CH2CH(CH3)2 From which of the following pairs of reagents can isoamyl acetate be made A. B. C. D. 20 Carboxylic acid Ethanoic acid Ethanoic acid 3-methylbutanoic acid Pentanoic acid Alcohol pentan-1-ol 3-methylbutan-1-ol ethanol ethanol The diagram below shows the set-up of an experiment. Br2 (l) limewater The unglazed porcelain in tube A is strongly heated and the glass wool is occasionally heated. Which of the following statements is / are correct? (1) A chemical reaction occurs at the glass wool. (2) There is colour change in the solution in tube B. (3) There is colour change in the solution in tube C. A. (1) only 21. B. (2) only C. (1) and (2) only D. (1) and (3) only What is the theoretical volume of carbon dioxide gas, measured at room temperature and pressure, that can be obtained by adding 100.0 cm3 of 0.120 mol dm–3 HCl(aq) to 1.10 g of Na2CO3(s)? (Molar volume of gas at room temperature and pressure = 24.0 dm3 mol–1) A. 125 cm3 22. A. B. C. D. B. 144 cm3 C. 250 cm3 D. 288 cm3 Which of the following correctly indicates the strongest intermolecular force that occurs in each of the following molecules? Molecule Strongest intermolecular force SO2 Dispersion forces CH3F Hydrogen bond BCl3 Dipole-dipole forces Ne Dispersion forces 6 23 The diagram below shows one type of breathalyzer for investigating drink-driving that consists of a fuel cell. When ethanol from the breath of the driver is allowed to get into contact with electrode X, the following change occurs. CH3CH2OH CH3COOH Which of the following statements about the fuel cell are correct? (1) Electrode X acts as the anode of the cell. (2) Electrons flow from electrode X to electrode Y through the acidic electrolyte. (3) A higher concentration of ethanol produces a larger current. A (1) and (2) only B (1) and (3) only C (2) and (3) only D (1), (2) and (3) 24 The elements, sodium to chlorine, in the third period of the periodic table shows a gradual change in properties. Which of the following changes is / are correct? (1) Their electronegativity increases. (2) Their oxides change from acidic to basic. (3) Their chlorides changes from ionic to covalent. A. (1) only B. (2) only C. (1) and (3) only D. (2) and (3) only 7 25. The diagram below shows a gas syringe containing a pale brown mixture of N2O4(g) and NO2(g) at equilibrium at room temperature. The plunger is quickly pushed from position A to position B at time t while the temperature of the mixture is kept constant. Which of the following graphs represents how the concentration of NO2(g) in the mixture varies until a new state of equilibrium is established? 26 Some brands of washing powder contain enzymes. Which of the following statements about the action of the enzymes is correct? A The enzymes increases the surface tension of water. B The enzymes decreases the hardness of water. C The enzymes facilitate the removal of specific kinds of dirt. D The activity of the enzymes increases with temperature. 8 27 . The concentration-time graph for a certain chemical reaction in a closed vessel of fixed volume is shown below: Which of the following chemical equation correctly represents the reaction? A. P(g) B. Q(g) C. 2P(g) D. 2Q(g) Q(g) P(g) Q(g) P(g) 28 Curve I is obtained in an experiment concerning the decomposition of 100 cm3 of 1.0 mol dm–3 hydrogen peroxide solution catalyzed by manganese(IV) oxide. 2H2O2(aq) 2H2O(l) + O2(g) Which of the following changes would produce curve II? A. Lowering the temperature B. Using more manganese(IV) oxide C. Using a smaller amount of 1.0 mol dm–3 hydrogen peroxide solution D. Adding some 0.2 mol dm–3 hydrogen peroxide solution 9 29 Which of the following alcohols is likely to be obtained on the hydrolysis of butter? 30 The three-dimensional structures of two 2-chlorobutanes are shown below. and Which of the following statements about them is / are correct? (1) They are structural isomers. (2) They have different effects on a beam of plane-polarized light. (3) They show the same chemical properties in all reactions. A (1) only 31 B (2) only C (1) and (3) only D (2) and (3) only An ester with an odour of banana has the following structural formula: Which of the following statements concerning aspirin are correct? (1) Its IUPAC name is ethyl methylbutanoate. (2) It has one chiral carbon atom. (3) It produces ethanoic acid on acid hydrolysis. A (1) and (2) only B (1) and (3) only C (2) and (3) only D (1), (2) and (3) Go on to the next page 10 32 The relative atomic mass of metal X is 63.5. Complete reduction of 42.9 g of this oxide by hydrogen gas produces metal X and 5.40 g of water. What is the empirical formula of the oxide? A. B. C. D. Directions: X2O XO X2O3 X3O2 Each question (Questions 33 – 36) consists of two separate statements. Decide whether each of the two statements is true or false; if both are true, then decide whether or not the second statement is a correct explanation of the first statement. Then select one option from A to D according to the following table : A Both statements are true and the 2nd statement is a correct explanation of the 1st statement. B Both statements are true but the 2nd statement is NOT a correct explanation of the 1st statement. C The 1st statement is false but the 2nd statement is true. D Both statements are false. 1st statement 2nd statement 33 Increasing pressure can increase the yield of any reversible chemical reaction. Increasing pressure would increase the equilibrium constant, Kc, of any reversible chemical reaction. 34 Nylon-6,6 has a giant covalent network structure. Nylon-6,6 is a condensation polymer. 35 The melting point of sulphur is lower than that of phosphorus. The strength of covalent bonds among the sulphur molecules is lower than that among the phosphorus molecules. 36 Greenhouse effect is reduced by installing catalytic converters in petroldriven cars. Installing catalytic converters in petrol catalytic driven cars can reduce the level of carbon monoxide at the road side. END OF SECTION A 11 SECTION B Answer ALL questions. Write your answers in the spaces provided. X, Y and Z are three different elements. X2+ ion, Y– ion and argon atom have the same electronic arrangement. Z belongs to the same period as X and the same group as Y in the periodic table. (a) Name the elements X, Y and Z (2 marks) (b) What is the electronic arrangement of Z? 2, 8, ____________________ Answers written in the margins will not be marked. (c) X reacts with nitrogen to give compound A. (i) Draw an electron diagram of compound A, showing electrons in the outermost shells only. (1 mark) (ii) (d) (1 mark) Compound A reacts with water to give a hydroxide and ammonia. Write a chemical equation for the reaction. Explain whether or not this reaction is a redox reaction. (2 marks) (i) Y combines with sulphur to form a compound with a chemical formula S2Y2. Draw an electron diagram of S2Y2, showing electrons in the outermost shells only. (1 mark) (ii) Y combines with phosphorus to form a compound with a chemical formula PY5. Draw a three-dimensional diagram to show the shape of a PY5 molecule. (1 mark) Answers written in the margins will not be marked. 12 Answers written in the margins will not be marked. 1 2 For each of the following experiments, state ONE observable change and write an equation for the reaction involved. (a) Adding sodium sulphite solution into acidified potassium dichromate solution (b) Putting copper into silver nitrate solution. (2 marks) (c) Adding magnesium to lemon juice. (2 marks) (d) Adding zinc into concentrated nitric acid. (2 marks) (e) Adding a few sodium hydroxide solution to zinc sulphate solution. (2 marks) Answers written in the margins will not be marked. 13 Answers written in the margins will not be marked. Answers written in the margins will not be marked. (2 marks) 3 Iron rods X and Y are coated with lead and zinc separately. However, part of the coating metal has been scratched to expose the iron underneath in each case. The iron rods are allowed to stand in air for some time. Predict whether iron rod X will rust. Explain your answer. (2 marks) (b) Predict whether iron rod Y will rust. Explain your answer. (2 marks) Answers written in the margins will not be marked. Answers written in the margins will not be marked. (a) Answers written in the margins will not be marked. 14 4 The following experiment is carried out to determine the concentration of copper(II) ions in a copper(II) nitrate solution: Step 1 Step 2 Step 3 (a) Add 25.0 cm3 of 1.20 mol dm–3 sodium hydroxide solution to 25.0 cm3 of copper(II) nitrate solution to precipitate out the copper(II) hydroxide. Remove the copper(II) hydroxide from the reaction mixture. Titrate the alkali left over in the reaction mixture against 0.400 mol dm–3 hydrochloric acid with a suitable indicator. 34.0 cm3 of the acid are required to reach the end point. Write an ionic equation for the reaction that occurs in Step 1. (1 mark) Suggest a suitable indicator for the titration in Step 3, and state the expected colour change at the end point. (2 marks) (c) (i) Based on the titration result in Step 3, calculate the number of moles of hydroxide ions left over in the reaction mixture. (1 mark) (ii) Calculate the concentration of copper(II) ions in the copper(II) nitrate solution. (3 marks) Answers written in the margins will not be marked. 15 Answers written in the margins will not be marked. Answers written in the margins will not be marked. (b) 5 An electroplating factory produces nickel-plated plastic turning knobs on radios. In the manufacturing process, the plastic knobs are first coated with copper and then electroplated with nickel. The formulation of the nickel-plating solution is shown below: (a) Why are the plastic knobs first coated with copper before electroplating? (1 mark) Write an ionic half-equation for the reaction that occurs at the cathode during electroplating. (1 mark) (c) The boric acid (H3BO3) in the formulation helps maintain the pH of the plating solution within a limited range. What would happen if the pH of the plating solution is too high? (1 mark) (d) Suggest a possible function of magnesium sulphate in the formulation. (e) Draw a labelled diagram of the experimental set-up used in a laboratory for coating a layer of nickel on an object by electroplating. (1 mark) (3 marks) Answers written in the margins will not be marked. 16 Answers written in the margins will not be marked. Answers written in the margins will not be marked. (b) 6 The table below shows some data of three carbon compounds. Compound Propan-1-ol Propan-2-ol Propanone (a) Structure CH3CH2CH2OH CH3CH(OH)CH3 CH3COCH3 Boiling point (°C) 97 82 56 Name the intermolecular attractions in propan-1-ol that are NOT present in propanone. (1 mark) (b) With the aid of a diagram, explain the formation of the attractions suggested in (i) in (3 marks) (c) Two identical steel balls are added separately to two identical glass cylinders each containing the same volume of propan-1-ol and propanone are shown. In which liquid does the steel ball take a longer time to reach the bottom? Explain your answer. (3 marks) Answers written in the margins will not be marked. 17 Answers written in the margins will not be marked. Answers written in the margins will not be marked. propan-1-ol. 7 Plastics are very useful materials. Many objects previously made with metals are now made with plastics. For each of the following objects, suggest ONE advantage of using plastics over using metals in making the object. (a) (b) (i) Cutlery (1 mark) (ii) Rubbish bin (1 mark) State whether you agree with the following statement. Explain your answer. ‘Landfilling is better than incineration for the disposal of plastic waste.’ Answers written in the margins will not be marked. Answers written in the margins will not be marked. (1 mark) Answers written in the margins will not be marked. 18 8 Hydrazine (N2H4(l)) and 1,1-dimethylhydrazine (N2H2(CH3)2(l)) both react spontaneously with oxygen and can be used as rocket fuels. N2H4(l) reacts with oxygen to give H2O(g) and N2(g) while N2H2(CH3)2(l) reacts with oxygen to give CO2(g), H2O(g) and N2(g). Given the following standard enthalpy changes of formation, decide whether the reaction of hydrazine or 1,1-dimethylhydrazine with oxygen provides more heat per gram of fuel. Compound N2H4(l) N2H2(CH3)2(l) CO2(g) H2O(g) Molar mass (g mol– 1 ) 32.0 60.0 44.0 18.0 ΔHOf (kJ mol–1) +51 +49 -394 -242 Answers written in the margins will not be marked. Answers written in the margins will not be marked. (6 marks) END OF PART I Answers written in the margins will not be marked. Go on to the next page 19 PART II Answer ALL questions. Write your answers in the spaces provided. 9 This question is about the reaction of iodine with propanone. CH3COCH3(aq) + I2(aq) CH3COCH2I(aq) + H+(aq) + I–(aq) The progress of the reaction can be followed by using a colorimeter. (a) Explain why a colorimeter can be used to follow the progress of the above reaction. (2 marks) Two samples were prepared and the progress of their reactions followed by a colorimeter. Sample Volume of 1 mol dm–3 propanone (cm3) 1 0.75 2 1.50 Volume of 1 mol dm–3 sulphuric acid (cm3) 0.75 0.75 Volume of distilled water (cm3) 1.50 0.75 Number of drops of 0.02 mol dm–3 I2(aq) 30 30 The progress of the reaction of Sample 1 was followed by a colorimeter and the results obtained are shown in the graph. Sketch, on the same graph, the expected results of Sample 2. (c) (2 marks) Besides using a colorimeter, suggest another method for following the progress of the reaction. State which of the reactants or products could be measured by the method suggested. (2 marks) Answers written in the margins will not be marked. 20 Answers written in the margins will not be marked. Answers written in the margins will not be marked. (b) 10 H2(g) is mixed with CO2(g) at 1800 K. The equilibrium is achieved according to the equation below: H2(g) + CO2(g) H2O(g) + CO(g) If the value of the equilibrium constant is 6.0, and the concentrations of each chemical species at 1800 K are as follows: [H2(g)] = 0.30 mol dm3; [CO2(g)] = 0.30 mol dm3; [H2O(g)] = 0.55 mol dm3; [CO(g)] = 0.55 mol dm3 (a) Write an expression for the equilibrium constant, Kc, for the above reaction. (1 mark) (c) Calculate the equilibrium concentrations of all chemical species at 1800 K. Answers written in the margins will not be marked. 21 (3 marks) Answers written in the margins will not be marked. Answers written in the margins will not be marked. (b) By finding the reaction quotient of the reaction mixture at 1800 K, state and explain briefly in which direction the equilibrium position shifts in order to attain new equilibrium at 1800 K. (2 marks) 11 Aspirin and paracetamol are common painkillers. (a) Intake of aspirin may lead to certain adverse side effects. State ONE such adverse side effect. (1 mark) (b) Name TWO functional groups present in aspirin and paracetamol respectively. (2 marks) Answers written in the margins will not be marked. 22 Answers written in the margins will not be marked. Answers written in the margins will not be marked. (d) In the graph below, sketch the changes in concentrations of hydrogen and carbon monoxide if a certain amount of CO(g) is added to the equilibrium system at time = t. (1 mark) (c) A student carried out some reactions with samples of aspirin and paracetamol in the laboratory. The student tried to react reagents X and Y with aspirin and paracetamol separately. • Reagent X reacted with both aspirin and paracetamol. • Reagent Y reacted only with aspirin. Suggest possible identities of reagents X and Y and the organic products that would form. Reagent Organic products formed when reacted with aspirin paracetamol Answers written in the margins will not be marked. Answers written in the margins will not be marked. Reagent X: Reagent Y: (5 marks) Answers written in the margins will not be marked. 23 12 Outline a synthetic route, with no more than four steps, to accomplish the following conversion. For each step, give the reagent(s), reaction conditions (as appropriate) and structure of the organic product. CH3COOH CH2BrCH2Br *13 Using manganese (Mn) as an example, illustrate THREE characteristics of transition metals. (4 marks) Answers written in the margins will not be marked. 24 Answers written in the margins will not be marked. Answers written in the margins will not be marked. (3 marks) 14. For each of the oxides below, draw its electron diagram (showing electrons in the outermost shells only), and state its behaviour in water. (i) Na2O (4 marks) END OF PART II END OF SECTION B Answers written in the margins will not be marked. 25 Answers written in the margins will not be marked. Answers written in the margins will not be marked. (ii) Cl2O 26