RI Prelim H1 P1

1 © RAFFLES INSTITUTION (JUNIOR COLLEGE) 2009 8872/P01/09 [Turn Over RAFFLES INSTITUTION (JC) PRELIMINARY EXAMINATION 2009 HIGHER 1 CHEMISTRY 8872/01 Paper 1 Multiple Choice 24 Septembe r 2009 50 minutes Additional Materials: Multiple Choice Answer Sheet Data Booklet READ THESE INSTRUCTIONS FIRST Do not open this question booklet until you are told to do so. Write in soft pencil. Do not use staples, paper clips, highlighters, glue or correction fluid. Write your name, class and index number in the spaces provided on the Answer Sheet. There are thirty 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 to be correct and record your choice with a soft pencil on the separate Answer Sheet. Read the instructions on the 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 booklet. This document consists of 14 printed pages. Raffles Institution Junior College

2 © RAFFLES INSTITUTION (JUNIOR COLLEGE) 2009 8872/P01/09 [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 and record your choice on the Multiple Choice Answer Sheet provided. 1. Naturally occurring silicon is a mixture of three isotopes, 28 Si, 29 Si and 30 Si. The relative atomic mass of silicon is 28.109. What could be the relative abundance of each of the three isotopes? A 91.1 % 28 Si, 7.9 % 29 Si and 1.0 % 30 Si B 92.2 % 28 Si, 4.7 % 29 Si and 3.1 % 30 Si C 95.0 % 28 Si, 3.2 % 29 Si and 1.8 % 30 Si D 96.3 % 28 Si, 0.3 % 29 Si and 3.4 % 30 Si 2. 10 cm 3 of a hydrocarbon was completely burnt in 100 cm 3 of oxygen. The volume of the residual gas obtained was 80 cm 3. When the residual gas was shaken with aqueous sod ium hydroxide, the volume decreased to 20 cm 3. Which one of the following represents the structure of the hydrocarbon? (All volumes are measured at room temperature and pressure). A C B D 3. 20.0 cm 3 of 0.0200 mol dm −3 bromate( V), BrO 3 − , was found to react completely with 80.0 cm 3 of 0.0100 mol dm −3 hydroxylamine, NH 2OH. BrO 3 − ions are reduced as follows: BrO 3 – + 6e – + 6H + → Br − + 3H 2O Which of the following could be the half-equation for the oxidation of hydroxylamine? A NH 2OH → ½N 2O + 2H + + ½H 2O + 2e − B NH 2OH → NO + 3H + + 3e − C NH 2OH + H 2O → NO 2 − + 5H + + 4e − D NH 2OH + 2H 2O → NO 3 − + 7H + + 6e −

3 © RAFFLES INSTITUTION (JUNIOR COLLEGE) 2009 8872/P01/09 [Turn Over 4. The following reaction is used in the titration of iron( II ) solution with acidified potassium dichromate( VI ). 6Fe 2+ + Cr 2O7 2– + 14H + → 6Fe 3+ + 2Cr 3+ + 7H 2O If 50.0 cm 3 of an iron(II) solution require 45.20 cm 3 of 0.100 mol dm –3 potassium dichromate(VI) for reaction, what is the mass of Fe2+ ions in 1 dm 3 of the iron(II) solution? A 12.6 g B 25.2 g C 30.3 g D 60.5 g 5. The successive ionisation energies, in kJ mol − 1, of an unknown element E are given below: 703 1610 2460 4350 5400 8500 10300 12300 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 E can conduct electricity in the solid and molten state. 6. Of the following, which is the strongest oxidising agent? A O2 + B O2 C O2 – D O2 2– 7. Which one of the following sets of compounds consis ts of a giant ionic structure, a giant covalent structure and a simple covalent structure? A C6H5CO 2H, P 4O10 and SiC B BaO 2, ICl3 and H 3PO 4 C C(diamond), A lCl3 and BC l3 D BC l3 , BaC l2 and SiO 2

4 © RAFFLES INSTITUTION (JUNIOR COLLEGE) 2009 8872/P01/09 [Turn Over 8. Which of the following best describes the change in bond angle in water when the ion H 3O+ is formed? A increases to approximately 107 o B increases to approximately 109 o C decreases to approximately 107o D decreases to approximately 109 o 9. Which of the equations correctly defines the standa rd enthalpy change of formation of a compound? A Na(s) + C l(g) → NaC l(s) B 2H 2(g) + O 2(g) → 2H 2O( l) C C(s) + O 2(g) → CO 2(g) D K(s) + Mn(s) + 2O 2(g) → KMnO 4(l) 10. The enthalpy change of reaction, ∆ Hr, between calcium and water to produce calcium hydroxide and hydrogen gas can be measured in the laboratory. What information, other than that obtained in the e xperiment above, is needed to calculate a value for the enthalpy change of formation of Ca(OH) 2(s)? A enthalpy change of vapourisation of calcium B enthalpy change of combustion of hydrogen C first and second ionisation energies of calcium D lattice energy of calcium hydroxide Ca(s) + O 2(g) + 2H2(g) Ca(s) + 2H 2O( l) Ca(OH) 2(s) + H 2(g) ∆ Hr

5 © RAFFLES INSTITUTION (JUNIOR COLLEGE) 2009 8872/P01/09 [Turn Over 11. Methanol is manufactured industrially by the catalytic reaction shown: CO(g) + 2H 2(g) /horizontalharpoonextender/horizontalharpoonextender/horizontalharpoonextender ⇀ ↽ /horizontalharpoonextender/horizontalharpoonextender /horizontalharpoonextender CH 3OH(g) ∆ H = −92 kJ mol −1 The operating conditions are 250 °C, a pressure of 75 atm and a copper-based catalyst. Which factor influences the choice of these conditions? A The catalyst increases the equilibrium yield of methanol. B At lower pressures, the rate of formation of methanol increases. C At lower temperatures, the rate of formation of methanol increases. D At lower temperatures, the equilibrium yield of methanol increases. 12. V and W can react together to reach equilibrium in the reaction below. V(g) + W(g) /horizontalharpoonextender/horizontalharpoonextender/horizontalharpoonextender ⇀ ↽ /horizontalharpoonextender/horizontalharpoonextender /horizontalharpoonextender X(g) + Y(g) In an experiment, 1.0 mole each of V and W were reacted at constant pressure P and temperature 350 oC. The amount of Y present in the mixture at intervals of time was re corded. The experiment was repeated at the same pressure P, but at a temperature of 700 oC. The results for both experiments are shown below. Which one of the following information cannot be deduced from the graph? A The activation energy of the forward reaction is high. B The enthalpy change for the forward reaction is negative. C The value of Kc decreases with an increase in temperature. D The rate at which equilibrium is achieved is faster at higher temperatures.

6 © RAFFLES INSTITUTION (JUNIOR COLLEGE) 2009 8872/P01/09 [Turn Over 13. Which substance, in 1 mol dm − 3 aqueous solution, would have the same hydrogen ion concentration as 1 mol dm − 3 of hydrochloric acid? A sodium hydroxide B ethanoic acid C sulfuric acid D nitric acid 14. For the reaction L(aq) + 2 M(aq) → N(aq), the rate equation is Rate = k [H +][ M]2 Which of the following statements is incorrect ? A H+ is a catalyst in the reaction. B When the concentr