2016 C1 Promotional Exam Paper 1

This question booklet consists of 8 printed pages. HWA CHONG INSTITUTION C1 Promotional Examination Higher 2 CANDIDATE NAME CT GROUP 16S CHEMISTRY Paper 1 Multiple Choice Additional Materials: Multiple Choice Answer Sheet Data Booklet. 9729/01 30 September 2016 40 min READ THESE INSTRUCTIONS FIRST Write in soft pencil. Complete the information on the Multiple Choice Answer Sheet as shown below. There are twenty 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 Multiple Choice Answer Sheet. 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 booklet. The use of an approved scientific calculator is expected, where appropriate. Write your name Write and shade your NRIC or FIN number Write your CT group

2 2016 HCI C1 H2 Chemistry Promotional Exam / Paper 1 SECTION A 1 The first ionization energies of five consecutive elements in the Periodic Table with proton number less than 20 are shown in the diagram. The sketches below represent two other properties of the same elements. What are properties X and Y? property X property Y A Electronegativity Atomic radius B Ionic radius Electronegativity C Melting point Atomic radius D Second ionization energy Effective nuclear charge 2 Which one of the following pairs has permanent dipole - permanent dipole interactions between molecules? A CHCl3 CH4 B CCl4 CClF3 C CClF3 CHCl3 D C2H5Cl C2Cl4 proton number 1st I.E proton number Property X proton number Property Y

3 2016 HCI C1 H2 Chemistry Promotional Exam / Paper 1 3 Three substances, X, Y and Z have physical properties as shown. substance melting point / oC boiling point / oC electrical conductivity of solid of liquid X Y Z 801 2852 3550 1413 3600 4827 poor poor good good good not known What could be the identities of X, Y, and Z? X Y Z A NaF BeCl2 Si B NaCl MgO graphite C NaBr CaO SiO2 D NaI Al2O3 diamond 4 Each of the following graphs represents plots for a fixed mass of ideal gas at two different conditions. Which of the following graphs is correct? A lower T higher T B lower P higher P C lower T higher T D lower T higher T 5 In a redox experiment, 20.0 cm3 of 0.125 mol dm–3 KIO4 was used to oxidize 25 cm3 of 0.8 mol dm–3 K2MnO4 to KMnO4. Which of the following formulae correctly represents the reduction product of the IO4– ion? A I– B IO– C IO2– D IO3– P PV T V V P 1/V P

4 2016 HCI C1 H2 Chemistry Promotional Exam / Paper 1 6 Excess chlorine was bubbled through 250 cm3 of aqueous sodium thiosulfate (Na2S2O3), oxidising thiosulfate to sulfate ions. 25.0 cm3 of the resultant solution was found to give 0.583 g of barium sulfate precipitate when treated with an excess of aqueous barium nitrate. What is the concentration, in mol dm–3, of sodium thiosulfate in the 250 cm3 solution used? A 0.005 B 0.050 C 0.100 D 0.243 7 Consider the following reactions: Mg (s) + 2HCl (aq) → MgCl2 (aq) + H2 (g) ∆Hrxn =  464 kJ mol–1 MgO (s) + 2HCl (aq) → MgCl2 (aq) + H2O (l) ∆Hrxn =  48 kJ mol–1 Given that the enthalpy change of formation of water is 285 kJ mol–1, what is the enthalpy change of formation of magnesium oxide? A  897 kJ mol–1 B  701 kJ mol–1 C  327 kJ mol–1 D  316 kJ mol–1 8 Which of the following has the same value as the standard enthalpy change of formation of carbon monoxide? 1 ∆Hc (graphite) − ∆Hc (CO) 2 ∆Hf (CO2) − ∆Hc (graphite) 3 ∆Hf (CO2) − ½∆Hatm (O) 4 ∆Hatm (graphite) − ∆Hatm (CO) + ∆Hatm (O) A 1 only B 1 and 2 only C 1 and 4 only D 3 and 4 only 9 The equation for the reduction of nitrogen monoxide is shown below. 2H2 + 2NO → N2 + 2H2O From initial rates experiments the following rate equation was derived. Rate = k[H2][NO]2 The results of the initial rates experiments are shown. What are the missing values, x, y and z? Initial [H2] / mol dm–3 Initial [NO] / mol dm–3 Initial rate / mol dm–3 min–1 0.5 2.0 6.0 0.5 1.0 x 1.0 1.0 y 1.0 z 0.75 x y z A 1.5 3.0 0.500 B 1.5 3.0 0.250 C 3.0 6.0 0.250

5 2016 HCI C1 H2 Chemistry Promotional Exam / Paper 1 D 3.0 6.0 0.125 10 In the diagram, curve X was obtained by observing the decomposition of 100 cm 3 of 1.0 mol dm–3 hydrogen peroxide, catalyzed by manganese (IV) oxide. Which alteration to the original experimental conditions on its own would produce curve Y? 1 Add more water 2 Lower the temperature 3 Use less manganese (IV) oxide 4 Add some 0.1 mol dm–3 hydrogen peroxide A 2 only B 4 only C 3 and 4 only D 1, 2 and 3 only 11 For which one of the following equilibria does Kc have units? A C(s) + S2(g) CS2(g) B 2CH3CO2H(aq) + Ba(OH)2(aq) Ba(CH3CO2)2(aq) + 2H2O(l) C CH3CO2H(l) + CH3CH2OH(l) CH3CO2CH2CH3(l) + H2O(l) D CO2(g) + CF4(g) 2COF2(g) 12 Consider the following reaction: Ag2CO3(s) Ag2O(s) + CO2(g) H > 0 What can be concluded from the above information? 1 Increasing pressure decreases the equilibrium yield of CO2. 2 The value of Kp increases with decreasing pressure. 3 The forward reaction is favoured at high temperatures. 4 Increasing the mass of Ag2CO3 increases the equilibrium yield of CO2. A 1 and 3 only B 1 and 4 only C 1, 2 and 3 only D 2, 3 and 4 only Y X

6 2016 HCI C1 H2 Chemistry Promotional Exam / Paper 1 13 The following shows two separate reactions I and II. Which of the following best describes reactions I and II? I II A addition condensation B addition elimination C elimination condensation D substitution elimination 14 How many stereoisomers are there in the molecule shown below? A 25 B 26 C 27 D 28 15 In the free radical chlorination of chloroethane, which of the following would be formed in the termination step? A H2 B HCl

7 2016 HCI C1 H2 Chemistry Promotional Exam / Paper 1 C D 16 In the free radical substitution of 2-methylbutane with limited bromine in the presence of uv light, a mixture of mono-brominated products were obtained. Which of the following is the correct combination of the products obtained (ignore stereoisomers)? A 5 possible products in the ratio of 3:3:3:2:1 B 4 possible products in the ratio of 3:3:3:2 C 4 possible products in the ratio of 6:3:2:1 D 3 possible products in the ratio of 9:2:1 17 Which of the following compounds is an addition product of the reaction between ethene with aqueous chlorine in the presence of a trace amount of KBr? 1 2 3 4 A 1, 2 and 4 only B 2, 3 and 4 only C 1 and 2 only D 3 and 4 only

8 2016 HCI C1 H2 Chemistry Promotional Exam / Paper 1 18 When the molecule of compound Q is treated with excess acidified hot concentrated manganate (VII) ions, which of the following compounds are obtained at the end of the reaction? 1 2 3 4 CO2 A 1, 2 and 4 only B 2, 3 and 4 only C 2 and 3 only D 1 and 4 only 19 Which of the following statements about the benzene molecule is correct? A It can conduct electricity. B It is susceptible t