JJC H2 Chem 2013 Prelim P1 QP

[Turn over JURONG JUNIOR COLLEGE 2013 JC 2 PRELIMINARY EXAMINATION Higher 2 CHEMISTRY 9647/01 Paper 1 Multiple Choice 19 September 2013 1 hour Candidates answer on separate paper. Additional Materials: Multiple Choice Answer Sheet Data Booklet READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, highlighters, glue or correction fluid. Write your name, class and exam index number on the Answer Sheet in the spaces provided unless this has been done for you. 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 separate Answer Sheet. Read the instructions on the Answer Sheet very carefully. Each correct answer will score on mark. A mark will not be deducted for a wrong answer. Any rough working should be done in this booklet. This document consists of 14 printed pages and 2 blank pages. 583

2 © Jurong Junior College 9647/01/PRELIM/2013 Section A For each question there are four possible answers, A, B, C, and D. Choose the one you consider to be correct. 1. A sample of cyclohexene is completely burnt in dry oxygen and the gaseous products are collected as shown. The increase in mass of the collecting vessels A and B of the apparatus are mA and mB respectively. What is the ratio of A B m m ? A 0.34 B 0.41 C 2.43 D 2.94 2. Some isotopes are unstable and undergo nuclear reactions. In one type of reaction, an unstable nucleus accepts an electron from an inner orbital of its electron cloud. The net effect is the conversion of a proton and an electron into a neutron. Which of the following describes this type of reaction? A 11C  12C B 111I  111Te C 76Br  75Br D 76Kr  75Br 3. Given the information: ∆H c(graphite) = –394 kJ mol–1 ∆Hf(H2O) = –286 kJ mol –1 ∆Hf(CH3OH) = –239 kJ mol –1 Which one of the following is the correct enthalpy change of combustion of methanol, CH 3OH, in kJ mol–1? A –441 B –727 C –919 D –1205 584

3 © Jurong Junior College 9647/01/PRELIM/2013 [Turn over 4. An experiment was conducted to determine the efficiency of the heating of a can of water using a spirit burner. The following data were recorded: Mass of ethanol burnt = m g Change in temperature of water = ∆T oC You are also given that: Relative molecular mass of ethanol = 46.0 Enthalpy change of combustion of ethanol = –1371 kJ mol −1 Specific heat capacity of water = c J g−1 K−1 Which expression below gives the efficiency of this heating process? A 1371 1000 100%300 T 46.0    m c B T4 6 . 0 100%300 1371 1000    mc C 300 T 46.0 100%1371    c m D 300 T 46.0 100%1371 1000    c m 5. The radius and charge of six ions are given in the table below: ion J+ L + M 2+ X – Y – Z 2– radius / nm 0.14 0.18 0.15 0.14 0.18 0.15 Given that the ionic solids, JX, LY and MZ are of the same lattice type, what is the order of their lattice energies (placing the most exothermic first)? A MZ > JX > LY B MZ > LY > JX C JX > MZ > LY D LY > MZ > JX 6. Consider the reaction: 2SO2(g) + O2(g) → 2SO3(g) ∆H = ‒198 kJ mol‒1; ∆S = ‒188 J K‒1 mol‒1 What conclusion can be drawn about this reaction? A The products are more disordered than the reactants. B The reaction is spontaneous under standard conditions. C As the reaction proceeds, the temperature will decrease. D As temperature increases, the reaction becomes more spontaneous. thermometer can containing 300 g of water burner containing ethanol 585

4 © Jurong Junior College 9647/01/PRELIM/2013 7. At 350 °C, 50 % of X decomposes according to the equation: X(g)  Y(g) + Z(g) If the equilibrium pressure is 1 3 p , what is the equilibrium constant, Kp, for the reaction at 350 °C? A 1 9 p B 1 6 p C 1 3 p D p 8. Dinitrogen tetraoxide dissociates into nitrogen dioxide as follows: N2O4(g)  2NO2(g) ∆H = +57 kJ mol‒1 If the temperature of an equilibrium mixture of the gases is increased at constant pressure, how would the volume of the mixture be affected? A The volume will increase, but only because of a shift of equilibrium towards the right. B The volume will increase, both because of a shift in equilibrium towards the right and also because of thermal expansion. C The volume will stay the same, because any thermal expansion could be exactly counteracted by a shift of equilibrium towards the left. D The volume will decrease, because a shift of equilibrium towards the left would more than counteract any thermal expansion. 9. A 0.100 mol dm3 solution of lead( II) nitrate is added, with stirring, into an equal volume of a solution containing a mixture of C l, Br, and I ions, each with the same concentration of 0.0100 mol dm3. Given the following data: Compound Numerical value of Ksp (at 25 °C) Lead(II) chloride 1.7 x 10‒5 Lead(II) bromide 6.6 x 10‒6 Lead(II) iodide 9.8 x 10‒9 Which one of the following statements is correct? A No precipitate will form. B Only PbI2 precipitate will form. C A mixture of PbI2 and PbBr2 precipitates will form. D All three precipitates, PbI2, PbBr2, and PbCl2, will form. 586

5 © Jurong Junior College 9647/01/PRELIM/2013 [Turn over 10. X and Y, with half ‒lives of 5 min and 15 min respectively, are two isotopes of a radioactive element. An experiment begins with 4 times as many atoms of X as of Y. Given that radioactive decay is a first ‒order reaction, how long will it take for the number of atoms of X left to become equal to the number of atoms of Y left? A 5 min B 10 min C 15 min D 20 min 11. Which of the following statements about the rate constant, k, of the chemical reaction given is true? A The rate constant is only dependent on temperature. B The forward and backward rate constants can have different units. C When a catalyst is added, the forward rate constant increases and the backward rate constant decreases. D When dynamic equilibrium is established, the rate constant for the forward and backward reaction is the same. 12. The use of the Data Booklet is relevant to this question. A cell is set up by connecting a Pb2+/Pb half‒cell and an acidified MnO4 −/Mn2+ half-cell. Which of the following is a correct description of the effect on the e.m.f of the cell when the corresponding change is made? Change Effect on e.m.f A Addition of NH3(aq) into oxidation half-cell Increases B Addition of H2SO4(aq) into reduction half-cell Decreases C Addition of NaOH(aq) into reduction half-cell Increases D Replace lead with an alloy of lead and zinc Remains the same 13. For the elements sodium to sulfur, which property would continuously increase numerically? A atomic radius B first ionisation energy C melting point D maximum oxidation number of the element in its oxide [Mn2+(aq)] = [H+(aq)] = [MnO4 −(aq)] = 1.0 mol dm‒3 voltmeter lead [Pb2+(aq)] = 1.0 mol dm‒3 salt bridge platinum V 587

6 © Jurong Junior College 9647/01/PRELIM/2013 14. To remove acidic impurity, the gaseous emissions of a coal ‒fired power station are passed through an aqueous suspension of a mineral followed by oxidation. Which of the following satisfies the above description? Acidic impurity Mineral Oxidised product A NO2 MgCO 3 Mg(NO 3)2 B P4O10 Ca(OH) 2 Ca 3(PO4)2 C SiO2 CaO CaSiO 3 D SO2 CaCO 3 CaSO 4 15. Which of the following properties of the Group II elements (Mg to Ba) and their compounds increases with increasin