MI H2 CHEM P1 Prelims

Class Adm No Candidate Name: This question paper consists of 20 printed pages and 2 blank pages. 2015 Preliminary Examination II Pre-university 3 H2 CHEMISTRY 9647/01 Paper 1 Multiple Choice 23rd Sept 2015 1 hour Additional materials: Multiple Choice Answer Sheet Data Booklet READ THESE INSTRUCTIONS FIRST Do not turn over this question paper until you are told to do so Write in soft pencil. Do not use staples, paper clips, glue or correction fluid. Write your name, class and admission number in the spaces provided at the top of this page and on the Multiple Choice Answer Sheet provided. 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 provided. Read the instructions on the Multiple Choice Answer Sheet very carefully. 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 question paper. The use of an approved scientific calculator is expected, where appropriate. FOR EXAMINER’S USE TOTAL (40 marks)

2 Section A For each question there are four possible answers, A, B, C, and D. Choose the one you consider to be correct. 1 On heating, 0.020 mol of the element M reacts with 0.020 mol of oxygen gas. What is the empirical formula of the oxide of M? A MO B MO2 C M2O D M2O2 2 The electronic configuration of four elements are given below. Which of these elements has the lowest first ionisation energy? A 1s2 2s2 2p3 B 1s2 2s2 2p4 C 1s2 2s2 2p6 3s2 3p3 D 1s2 2s2 2p6 3s2 3p4 3 In which pair of compounds is the permanent dipole moment in Compound I smaller than that in Compound II? Compound I Compound II A CH3CH2Br CH3CHBr2 B CH3CH2F CH3CH2Br C D

3 [Turn over 4 Iodine solid has a density of 4.93 g cm-3. What is the volume of iodine vapour formed w hen 1 cm 3 of solid iodine at room temperature was heated to 300 °C at a pressure of 1 atm? A 0.478 dm3 B 0.912 dm3 C 0.955 dm3 D 1.82 dm3 5 Glucose has the formula C6H12O6. It undergoes combustion in excess oxygen. Some standard enthalpy change of formation values are given below: compound ΔHf o/kJ mol-1 H2O(l) -286 CO2(g) -394 C6H12O6(s) -1273 Which of the following options correctly describes the signs of ΔHo and ΔSo for the combustion reaction of glucose? ΔHo ΔSo A – – B – + C + – D + +

4 6 During electrolysis using inert electrodes , a large current was passed through a dilute copper(II) sulfate solution. What are the products formed at the anode and cathode? anode cathode A copper metal sulfur dioxide gas B oxygen gas copper metal C S2O8 2- ions copper metal D sulfur dioxide gas copper metal 7 Two equilibria are shown below. 2AB(g) ⇌ A2(g) + B2(g) reaction 1 ½A2(g) + ½B2(g) ⇌ AB(g) reaction 2 The numerical value of Kc for reaction 1 is 4. Under the same conditions, what is the numerical value of Kc for reaction 2? A 1 4 B 1 2 C 2 D 4 8 The following equation shows the dissociation of water at 298 K. H2O(l) ⇌ H+(aq) + OH–(aq) ΔH > 0 The ionic product of water is defined by the following expression at 298 K. [H+][OH–] = 1.0 x 10-14 mol2 dm-6 Which of the following can be deduced from these data? A When water is cooled only the concentration of H+(aq) increases. B When water is cooled the concentration of both H+(aq) and OH–(aq) increases. C Water is alkaline at temperatures below 298 K. D The pH of water at temperatures below 298 K is greater than 7.

5 [Turn over 9 The value of solubility product, Ksp, of silver ethanedioate, Ag2C2O4, at 298 K is 6.10 x 10-12. What is the concentration of Ag+ in a saturated solution of Ag2C2O4 at 298 K? A 1.23 x 10-6 mol dm-3 B 2.47 x 10-6 mol dm-3 C 1.15 x 10-4 mol dm-3 D 2.30 x 10-4 mol dm-3 10 The rate of reaction between bromine and methanoic acid is first order with respect to both bromine and to methanoic acid. Br2(aq) + HCOOH(aq) → 2Br –(aq) + 2H+(aq) + CO2(g) Which of the following statements about the reaction above is true? A The unit for the rate constant is mol dm-3 s-1. B The overall order of the reaction is one. C Halving the concentration of bromine halves the rate of evolution of gas. D Doubling the concentration of methanoic acid will not affect the rate of reaction. 11 At a crime scene, some samples of fibres were collected from the victim and sent to the forensic laboratory. Upon analysis, the fib res were found to contain an oxide of E and a chloride of G. E and G are elements of Period 3 and the following are known:  Oxide of E has a very high melting point and it does not dissolve in water. It is a good conductor of electricity in molten state.  Chloride of G has a low melting point and it dissolves readily in water to give a solution which turns blue litmus paper red. It is a non-conductor of electricity. What are the possible identities of the two fibres? Oxide of E Chloride of G A Al2O3 SiCl4 B Al2O3 MgCl2 C Na2O PCl3 D SiO2 NaCl

6 12 A mixture of the oxides of two elements in Period 3 is dissolved in water. The resultant solution is acidic. What could be the constituents of the mixture? A MgO and Al2O3 B Na2O and MgO C Na2O and SiO2 D P4O10 and SO2 13 The diagram below represents the melting points of four consecutive elements in Period 3 of the Periodic Table. The sketches below represent another two properties of the same elements. What are properties 1 and 2? Property 1 Property 2 A first ionisation energy atomic radius B electrical conductivity electronegativity C second ionisation energy atomic radius D electrical conductivity first ionisation energy     proton number 0 melting point / K     proton number 0 property 1     proton number 0 property 2

7 [Turn over 14 Which one of the following statements about Group II elements (magnesium to barium) or their compounds is incorrect? A Reactivity of Group II elements with oxygen increases down the group. B The stability of the carbonate to heat increases down the group. C The tendency to form complex ions increases down the group. D The pH of the aqueous oxides are all above 7. 15 Two separate experiments were carried out with anhydrous potassium bromide. Experiment 1: Concentrated sulfuric acid was added to the potassium b romide and heated. The resultant solution was added to potassium iodide solution. Experiment 2: The potassium bromide was dissolved in concentrated aqueous ammonia and this wa s then added to aqueous silver nitrate. What are the observations for experiment 1 and 2 respectively? Observation for experiment 1 Observation for experiment 2 A brown solution cream precipitate B brown solution no precipitate C purple solution cream precipitate D purple solution no precipitate

8 16 Use of the Data Booklet is relevant to this question. Vanadium is a transition metal that can form stable coloured ions of various oxidation states in aqueous solutions. Some of the ions of vanadium and their corresponding colours are shown in the table below. formula of vanadium ion VO3 – VO2+ V3+ V2+ colour of aqueous solution yellow blue green violet What is the final colour of the solution when excess lead metal is added to a n acidified solution of VO2+? A blue B gree