ANDERSON JUNIOR COLLEGE2007 PRELIMINARY EXAMINATION CHEMISTRY 9746/01 Higher 2 Paper 1 Multiple Choice Monday 17 SEPTEMBER 2007 1 hour Name : _________________________________ Reg. No.: ______ PDG : ______ INSTRUCTIONS TO CANDIDATES Do NOT open this question booklet until you are told to do so. Do not use staples, highlighters, glue or correction fluid on the optical answer sheet (OAS). 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 in the separate answer sheet provided. Each correct answer will score the mark. A mark will not be deducted for a wrong answer. Do not write anything on the Data Booklet. Any rough working should be done in this booklet. You may use a calculator. INFORMATION FOR CANDIDATES Additional Materials : Data Booklet Optical Answer Sheet (OAS) Shading of Optical Answer Sheet (OAS) Shade the last 5 digits of your NRIC / FIN number. Do NOT shade the reference letter. Section 2 Subject title : H2 Chemistry Section 3 Test name : 2007 Prelim Exam This question paper consists of 15 printed pages including this page. ajc/H2prelim/paper 3/2007 1 1 Chlorine gas is a severe irritant to the eyes and respiratory system. The maximum safe toleration level of chlorine gas in air is 0.005 mg dm -3 . How many chlorine atoms are present in 500 cm 3 of air at this toleration level? A 23 10 6 35.5 0.005 × × B 23 10 6 2 71 1 1000 0.005 × × × × C 23 10 6 2 1 71 0.005 × × × ajc/H2prelim/paper 3/2007 2 D 23 10 6 71 1 1000 0.005 × × × 2 10 cm 3 of a hydrocarbon was mixed with 100 cm 3 of oxygen gas which is in excess. The mixture was exploded and after cooling to room temperature, the residual gases occupied a volume of 80 cm 3 . Upon passing the residual gases through sodium hydroxide, this volume decreased to 50 cm 3 . What is the formula of the unknown hydrocarbon? A C 3 H 6 B C 3 H 8 C C 4 H 8 D C 4 H 10 3 Flask X contains 1 dm 3 of helium at a pressure of 2 kPa and flask Y contains 2 dm 3 of neon at a pressure of 1 kPa. If the flasks are connected at constant temperature, what is the final pressure? A 3 1 1 kPa B 3 2 1 kPa C 2 1 1 kPa D 2 kPa 4 Which of the following contains only one unpaired electron? A Ga – B Se – C Te + D As + 5 Which one of the following pairs has permanent dipole – permanent dipole interactions between molecules I and II? Molecule I Molecule II A CHCl 3 CH 4 B CCl 4 CClF 3 C CClF 3 CHCl 3 D C 2 H 5 Cl C 2 Cl 4 6 The successive ionization energies, in kJ mol -1 , of an unknown element E are given below. 420 3100 4400 5900 8000 9600 11400 13300 Which of the following statements about E is correct? A E is in group II of the Periodic Table. B The oxide of E is an amphoteric oxide. C The chloride of E hydrolyses in water to give an acidic pH. D Element E can conduct electricity in the solid and molten state. 7 Which one of the following sets of solid elements includes a giant metallic structure, a macromolecular structure and a simple molecular structure? A Na Mg C B Mg Al S C C Si S D Al Si S 8 The reduction of the iron ore, Fe 2 O 3 by carbon monoxide is an exothermic reaction which occurs in the upper part of the furnace. Fe 2 O 3 (s) + 3CO (g) 2Fe (s) +3CO 2 (g) ΔH =– 27 kJ mol –1 Given that ΔH f θ for CO 2 (g) =– 394 kJ mol –1 and ΔH f θ for CO (g) =– 110 kJ mol –1 , what is the standard enthalpy change of formation of the iron ore? A +257 kJ mol –1 B +825 kJ mol –1 C – 257 kJ mol –1 D – 825 kJ mol –1 ajc/H2prelim/paper 3/2007 3 9 A typical protein forms several hundreds of hydrogen bonds and several thousands of Van der Waals’ forces in folding from primary to tertiary structures. Which of the following thermodynamic state functions of the protein best represents the folding process? ΔG / kJ mol –1 ΔH / kJ mol –1 ΔS / J K –1 mol –1 A <0 <0 <0 B <0 <0 >0 C >0 >0 >0 D >0 >0 <0 10 Electroplating is an electrolytic process of coating an object with a thin layer of metal. Which of the following factors will affect the mass of chromium deposited at the cathode during the process of coating chromium on utensil? A Size of the anode B Size of the cathode C Size of the current D Concentration of the electrolyte 11 Zinc oxide reacts with hydrogen according to the following equation. ZnO(s) + H 2 (g) Zn(s) + H 2 O(g) At temperature T and a total pressure of 10 atm, it is found that initial amounts of 1 mole each of zinc oxide and hydrogen gas produce 0.01 mole each of zinc and steam at equilibrium. What is the approximate value of K p at temperature T? A 10 -5 B 10 -2 C 10 D 100 12 What is the pH of the resultant solution when equal volumes of a solution of pH 1 and a solution of pH 3 are added together? A 1.3 B 1.5 C 2.0 D 2.5 ajc/H2prelim/paper 3/2007 4 13 The reaction of nitrogen monoxide with hydrogen 2NO (g) + 2H 2 (g) N 2 (g) + 2H 2 O (g) is thought to involve the following steps: 2NO (g) + H 2 (g) N 2 O (g) + H 2 O (g) (slow) N 2 O (g) + H 2 (g) N 2 (g) + H 2 O (g) (fast) Which of the following statements is correct? A Hydrogen is reduced by nitrogen monoxide. B The reaction is second order with respect to H 2 . C The rate equation for the reaction is: rate =k [NO] 2 [H 2 ]. D N 2 O acts as a catalyst in this reaction. 14 The percentage of ammonia obtainable at equilibrium during the Haber process is plotted against the operation pressure for two temperatures, 400ºC and 500ºC. Which of the following correctly represents the two graphs? A B C D ajc/H2prelim/paper 3/2007 5 15 The ionic radius of the elements in Period 3 (Na to Cl) changes across the period. Which of the following statements does not explain the trend of the ionic radius across the period? A Across the period, there is an increase in nuclear charge. B The anions have greater screening effect than the cations. C There is constant screening effect among the cations. D The effective nuclear charge decreases from P 3- to Cl - . 16 Figure 1 shows the first six ionisation energies of an element X. Figure 2 shows the first ionisation energy of eight consecutive elements (including X) of Period 3. 1st IE (across Period 3) atomi c number 1 s t i o n i s a t i o n e n e r g y / k J m o l - 1 1st 6 ionisation energies of X 1 2 3 4 5 6 no. of el ectron(s) removed i o n i s a t i o n e n e r g y / k J m o l - 1 D C B A Figure 1 Figure 2 With reference to Figure 2, which of the options corresponds to the first ionisation energy of element X? 17 Which of the following statements is true about the trends in the properties of the Group VII elements (Cl 2 to I 2 )? A The volatility increases down the group. B The electronegativity increases down the group. C The oxidising power decreases down the group. D The colour intensity decreases down the group. ajc/H2prelim/paper 3/2007 6 18 Chlorine gas is pumped continuously into hot aqueous potassium hydroxide. Which anions are formed? A Cl - and ClO - B Cl - and ClO 3 - C Cl - and ClO 4 - D ClO - and ClO 3 - 19 Use of the Data Booklet is relevant to this question. Peroxodisulphate(VI), S 2 O 8 2- , is capable of oxidising the tartrate ion, [CH(OH)CO 2 ] 2 to carbon dioxide and methanoate as shown in the following reaction. H C CO 2 - HO CO H C 2 - HO + 3S 2 O 8 2- + 2H 2 O 2CO 2 + 2HCO 2 - +6H + + 6SO 4 2- The reaction can be catalysed by a homogenous catalyst. Given that the electrode potential for the tartrate ion is C - HO H CO 2 C CO 2 - HO H 2CO 2 +2HCO 2 - +6H + +6e + 2H 2 O E θ =+0.56V Which metal ion is not a suitable catalyst for this reaction? A Co 3+ B Mn 3+ C Fe 3+ D V 3+ 20 Compound G is optically active. Cl C Cl H C O H How many chiral centre(s) does compound G have? A 1 B 2 C 3 D 4 ajc/H2prelim/paper 3/2007 7 21 Oxidation of an alkene Y gives a diol; further oxidation gives a diketone. Which one of the following could be Y? A CH 3 CH=CH 2 B CH 3 CH=CHCH 3 C CH 3 CH=C(CH 3 ) 2 D (CH 3 ) 2 C=C(CH 3 ) 2 22 Benzene reacts with chlorine as shown: C 6 H 6 + Cl 2 C 6 H 5 Cl + HCl Which term describes this type of reaction? A Free radical substitution B Electrophilic substitution C Electrophilic addition D Nucleophilic addition 23 1 mole of an organic compound P undergoes elimination on reaction with ethanolic sodium hydroxide to form 2 moles of HBr. What could P be? A B Br CH 2 CHCH 3 Br Br CH 2 Br C D BrCH 2 C CH 2 Br CH 3 CH 3 CH 3 C CH 3 Br Br ajc/H2prelim/paper 3/2007 8 24 When an organic compound Q was treated with phosphorus pentachloride, fumes of hydrogen chloride were evolved. When Q was warmed with alkaline aqueous iodine, a yellow precipitate was formed. Which of the following was Q? A CH 3 COOH B CH 3 COCH 2 CH 3 C (CH 3 ) 3 COH D CH 3 CH(OH)CH 2 CH 3 25 The anti-bacterial drug tetracycline has the formula OH NH 2 O O O OH OH OH CH 3 HO N H 3 C CH 3 Which statement about tetracycline is correct? A It does not react with SOCl 2 . B It reacts with sodium carbonate to liberate carbon dioxide gas. C 3 moles of HBr is formed when 1 mole of tetracycline reacts in an excess of aqueous bromine in the dark. D It reacts with sodium metal to liberate H 2 gas. 26 Which of the following pair of compounds would produce the same carboxylic acid upon hydrolysis? A CH 3 CH 2 COCl CH 3 CO 2 CH 3 B CH 3 CH 2 CN CH 3 CO 2 CH 2 CH 3 C CH 3 CH 2 CN CH 3 CH 2 CO 2 CH 3 D C 6 H 5 CONH 2 C 6 H 5 NHCOCH 3 ajc/H2prelim/paper 3/2007 9 27 Oestrone, a sex hormone, has the following structural formula. HO O CH 3 Which reagent would be expected to react with this compound? A lithium aluminium hydride B concentrated sulphuric acid C alkaline aqueous iodine D acidified potassium manganate(VII) 28 A nitrile X undergoes the following two reactions: Nitrile X product, C 2 H 5 NH 2 product reduction hydrolysis What would be produced when the products from the two reactions are mixed together? A [ CH 3 CH 2 NH 3 + ] [ – O 2 CCH 3 ] B [ CH 3 CH 2 NH 3 + ] [ – O 2 CCH 2 CH 3 ] C CH 3 CONHCH 2 CH 3 D CH 3 CH 2 CONHCH 2 CH 3 ajc/H2prelim/paper 3/2007 10 29 Which sequence shows the nitrogen compounds in increasing order of basic strength? least basic most basic A CH 3 C O NH 2 NH 2 Cl CH 3 NH CH 3 B CH 3 C O NH 2 CH 3 NH CH 3 NH 2 Cl C CH 3 NH CH 3 NH 2 Cl CH 3 C O NH 2 D NH 2 Cl CH 3 C O NH 2 CH 3 NH CH 3 30 A sample of serine is dissolved in a buffer solution of pH 12. H 2 N CH COOH CH 2 OH serine Which form will be predominant at this pH? A B H 3 N CH COO - CH 2 OH H 3 N CH COOH CH 2 OH C D H 2 N CH COO - CH 2 OH H 2 N CH COO - CH 2 O - ajc/H2prelim/paper 3/2007 11 For each of the questions in this section one or more of the three numbered statements 1 to 3 may be correct. Decide whether each of the statements is or is not correct (you may find it helpful to put a tick against the statements which you consider to be correct.) The responses A to D should be selected on the basis of A B C D 1, 2 and 3 are correct 1 and 2 only are correct 2 and 3 only are correct 1 only is correct No other combination of statements is used as a correct response 31 In which of the following reactions is the bond angle in the product greater than that in the reactant? 1 H 2 O(l) +H + (aq) → H 3 O + (aq) 2 C 2 H 4 (g) +H 2 (g) → C 2 H 6 (g) 3 CO 2 (g) +OH − (aq) → HCO 3 − (aq) 32 A cell with a standard potential, E , of +1.53 V is shown below using conventional notation. θ cell Zn | Zn 2+ (aq) || Fe 3+ (aq), Fe 2+ (aq) | Pt Which of the following changes, when made separately to the set-up above, will not affect the E ? θ cell 1 Adding water to the Fe 3+ /Fe 2+ half-cell 2 Increasing the size of the zinc electrode 3 Increasing the concentration of zinc ions ajc/H2prelim/paper 3/2007 12 33 Hydrogen sulphide gas is bubbled into an acidified solution containing 0.10 mol dm -3 of zinc sulphate and 0.10 mol dm -3 of copper(II) sulphate at 15ºC. The concentration of S 2- (aq) in the solution at this point is 10 -35 mol dm -3 . The solubility product of zinc sulphide at 15°C is 10 -24 mol -2 dm -6 and that of copper(II) sulphide is 10 -40 mol 2 dm -6 . Which of the following statements are correct? 1 Zinc sulphide is more soluble than copper(II) sulphide at 15°C. 2 Only copper(II) sulphide is precipitated. 3 The solubility products of zinc sulphide and copper(II) sulphide will decrease when the concentration of S 2- (aq) is increased. 34 Which graph would confirm that the rate of decomposition of hydrogen peroxide is first order with respect to the concentration of hydrogen peroxide? 1 rate [H 2 O 2 ] 2 [H 2 O 2 ] time 3 rate [H 2 O 2 ] 35 Which of the following statements are true about the elements of Group II (Mg to Ba) and their oxides? 1 Their oxides are basic. 2 The elements react with steam to give hydrogen. 3 The solubility of the oxides increases down the group. ajc/H2prelim/paper 3/2007 13 36 Vanadium has the electronic structure 1s 2 2s 2 2p 6 3s 2 3p 6 3d 3 4s 2 . Which compound is likely to exist? 1 V 2 O 5 2 VOCl 3 K 2 V 2 O 7 37 Which of the following compounds will give a white precipitate when heated with aqueous silver nitrate? 1 C 6 H 5 CH 2 Cl 2 C 6 H 5 COCl 3 C 6 H 5 Cl 38 Which of the following reagents can be used to distinguish between the following two compounds? CH 2 CH 3 OH CH 2 CH 2 OH 1 Br 2 (aq) 2 KMnO 4 3 Na 39 Which of the following statements are true for compound A? CH 2 CH O HOOC A 1 It gives a orange precipitate with 2,4-dinitrophenylhydrazine. 2 It gives a silver precipitate with Tollens’ reagent. 3 It undergoes esterification with phenol. ajc/H2prelim/paper 3/2007 14 40 The structure of the herbicide Karbutilate is shown below. O C O NH C(CH 3 ) 3 NH C O N(CH 3 ) 2 What would be formed by prolonged boiling of Karbutilate with aqueous sodium hydroxide? 1 O - Na + NHCO 2 - Na + 2 O - Na + NH 2 3 H 2 NC(CH 3 ) 3 ------ END OF PAPER ------ ajc/H2prelim/paper 3/2007 15