AJC H2 CHEM P1

AJC JC2 PRELIM 2014 9647/01/H2 [Turn over ANDERSON JUNIOR COLLEGE 2014 JC2 PRELIMINARY EXAMINATIONS CHEMISTRY 9647/01 Higher 2 22 September 2014 Paper 1 Multiple Choice 1 hour 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. 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 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. This document consists of 19 printed pages. Multiple Choice Answer Sheet Write your name, PDG and NRIC / FIN number, including the reference letter. Shade the NRIC / FIN number. Exam Title: JC2 Prelim Exam Details: H2 Chemistry / Paper 1 Date: 22/09/2014

2 AJC JC2 PRELIM 2014 9647/01/H2 [Turn over Section A For each question there are four possible answers, A, B, C and D. Choose the one you consider to be correct.   1 Dilute sulfuric acid was added to aqueous barium hydroxide until the acid was present in excess. How will the total number of ions present in solution in the reacting mixture vary? A B C D     2 When iron reacts with aqueous iron(III) ions, iron(II) ions are formed as the only product. A final mixture, after the reaction has taken place, contains equal numbers of moles of Fe 2+(aq) and Fe3+(aq). Assuming the reaction has gone to completion, how many moles of Fe(s) and Fe3+(aq) were in the starting mixture? moles of Fe(s) moles of Fe 3+(aq) A 1 2 B 1 3 C 1 5 D 2 3       number of ions amount of acid added 0 number of ions amount of acid added 0 number of ions amount of acid added 0 number of ions amount of acid added 0

3 AJC JC2 PRELIM 2014 9647/01/H2 [Turn over energy energy energy energy   3 A sample of the element Americium (Am) was vaporised, ionised and passed through an electric field. It was observed that a beam of 241Am+ particles gave an angle of deflection of +2. Assuming an identical set of experimental conditions, by what angle would a beam of 32S– particles be deflected? A +15.1 B –15.1 C +30.1 D –30.1 4 Which diagram best shows the shapes and relative energies of the valence orbitals of carbon in a molecule of ethene? A 2s sp3 B sp3   2s   C sp2 2p D 2p sp2 241Am+ +2 + –

4 AJC JC2 PRELIM 2014 9647/01/H2 [Turn over 5 Which of the following diagrams correctly describes the behaviour of a fixed mass of an ideal gas? A B C D 6 Which of the following reactions results in an increase in the bond angle of the underlined substances? A CO 2 + 2NaOH Na2CO3 + H2O B BH3 + NaH NaBH4 C NaNH2 + H2O NH3 + NaOH D XeF2 + F2 XeF4 T/K At constant V pV V At constant T pV T/K At constant p V 1/V At constant T p

5 AJC JC2 PRELIM 2014 9647/01/H2 [Turn over 7 In which pair do the isomers have identical boiling points? A C CH3 CH2Cl H Cl and C CH3 ClCH2 H Cl B andCC H CH3 H3C H CC CH3 H H3C H C CH3CH2CH2CH2OH and (CH3)2CHCH2OH D CH3(CH2)4CH3 and (CH3)2CHCH(CH3)2 8 Which value is essential to calculate the lattice energy of the compound NaH? A electron affinity of hydrogen B electron affinity of sodium C first ionisation energy of hydrogen D second ionisation energy of sodium 9 Given that EDTA 4– has the following structure, NC H 2CH2 CH2COO CH2COO N CH2COO CH2COO which of the following statements about the reaction involving the hexaaquacopper(II) ion below is incorrect? [Cu(H 2O)6]2+ + EDTA4– [Cu(EDTA)]2– + 6H2O A The entropy change for the forward reaction is positive. B The copper undergoes a change in oxidation state. C The number of bonds broken and that of bonds formed are identical. D Both [Cu(H2O)6]2+ and Cu(EDTA)]2– are octahedral complexes.

6 AJC JC2 PRELIM 2014 9647/01/H2 [Turn over 10 What is the half–life of a radioactive isotope if its rate of decay decreases from 300 counts per minute to 37.5 counts per minute after 1 day? A 4 hours B 6 hours C 8 hours D 12 hours 11 Use of the Data Booklet is relevant to this question. Spatulas are often made from nickel. By considering the relevant E o values, which of the following aqueous ions should not be stirred with a nickel spatula because a reaction could occur? A Cr3+ B Mn2+ C Pb2+ D V2+ 12 Use of the Data Booklet is relevant to this question. Sodium chlorate(V) is an important industrial chemical with many thousands of tons being used each year to manufacture chlorine dioxide bleach for the paper industry. It is made commercially by the electrolysis of concentrated sodium chloride (brine) using inert electrodes. The products of this process are chlorine, hydrogen and sodium hydroxide. What is the maximum yield of each of these products when 58.5 kg of concentrated sodium chloride is electrolysed? chlorine hydrogen sodium hydroxide A 35.5 kg 1 kg 40 kg B 35.5 kg 2 kg 40 kg C 71 kg 1 kg 80 kg D 71 kg 2 kg 80 kg

7 AJC JC2 PRELIM 2014 9647/01/H2 [Turn over 13 The reaction between carbon monoxide and chlorine was studied in an experiment by mixing the two gases and changing the reaction conditions inside the reaction vessel at different times during the experiment. The concentrations of the gases in the vessel were followed with time, and the following graph is obtained. CO(g) + Cl 2(g) COCl2(g) Ho = –113.4 kJ mol–1 Which one of the following conclusions deduced from the graph is incorrect? A The rate of forward reaction equals the rate of backward reaction at 7 min. B The equilibrium constant, K c, for the system when determined at 7 min is 2.4 mol–1 dm3. C The change in concentration during the period 7.5 min to 10 min was produced by an increase in pressure at constant temperature. D The change in concentration during the period 10 min to 15 min was produced by the addition of more chlorine. 14 In recent years, many new inventions hav e been aimed at developing methods to recover carbon dioxide due to its undesirable impact on raising global temperatures. One method involves the Bosch reaction where carbon dioxide and hydrogen are heated over a catalyst in the first stage. CO 2(g) + H2(g) CO(g) + H2O(g) In the second stage, the carbon monoxide is converted to solid carbon and more water. A mixture of carbon dioxide and hydrogen in the mole ratio of 1 : 1 is passed over a heated catalyst at 1000 °C and 1 atm. Given that the equilibrium constant, K p, for the first stage of the Bosch reaction is 0.726 at 1000 °C, what will be the mole fraction of carbon monoxide present at equilibrium after the first stage? A 0.23 B 0.46 C 0.50 D 1.54 0 0.1 0.2 0.3 0.4 0.5 0.6 0.9 1.0 0.7 concentration / mol dm–3 time / min 0.8 5 10 15 7.5 CO(g) Cl2(g) COCl2(g)

8 AJC JC2 PRELIM 2014 9647/01/H2 [Turn over 15 Which statement explains the observation that magnesium hydroxide dissolves in aqueous ammonium chloride, but not in aqueous sodium chloride? A The ionic radius of the NH4 + ion is similar to that of Mg2+ but not that of Na+. B NH4Cl dissociates less fully than NaCl. C The Na+ and Mg2+ ions hav