NYJC H2 Chem 2013 Prelim P1 QP

NANYANG JUNIOR COLLEGE JC 2 PRELIMINARY EXAMINATION Higher 2 CHEMISTRY 9647/01 Paper 1 Multiple Choice 23 Sep 2013 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. Write your name, class and tutor’s name 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 and D. Choose the one you consider correct and record you choice in 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 19 printed pages. [Turn over 3

2 H2 Chemistry 9647/01 NYJC J2/2013 Prelim 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 15 cm 3 mixture of carbon monoxide and methane was mixed with excess oxygen and exploded. There was a c ontraction in volume of 15 cm 3 at room temperature and pressure. What is the percentage by volume of methane in the mixture? A 33 B 50 C 60 D 75 2 Nitrogen is essential in plant s for the synthesis of pr oteins and nuclei acids. A farmer intends to switch his nitrogen fertiliser from potassium nitrate to urea. Currently, he uses 300 kg of potassium nitrate per month. Given the following information about the two fertilisers, calculate his monthly savings (to the nearest dollar) if he switches to urea as a fertiliser. Fertiliser Potassium nitrate Urea Chemical Formula KNO3 CO(NH 2)2 Mr 101.1 60.0 Cost / tonne [1 tonne = 1000 kg] $850 $340 A $310 B $225 C $195 D $153 4

3 H2 Chemistry 9647/01 NYJC J2/2013 Prelim [Turn over + – R S T 3 The following are flight paths of charged particles when accelerated in an electric field. Which of the following are correct positions for the particles? R S T A 16O+ 14C+ 14N+ B 15O⎯ 14C+ 28Si+ C 14N⎯ 15O+ 28Si2+ D 14N⎯ 14C+ 28Si4+ 4 Consider the following reac tion of aluminium chloride: AlCl3 + Cl– ⇌ [AlCl4]– Which of the following is correct regarding AlCl3 and [AlCl4]–? A Both AlCl3 and [AlCl4]– are tetrahedral in shape. B A lCl3 is tetrahedral in shape and [AlCl4]– is planar in shape. C The C l–Al–Cl bond angle in AlCl3 is larger than that in [AlCl4]–. D There are more electron pairs around the A l atom in A lCl3 than that in [AlCl4]–. 5

4 H2 Chemistry 9647/01 NYJC J2/2013 Prelim 5 The graph of P / kPa against (1 / V) / m –3 was obtained for 0.400 g of an unknown gas at 25 C. What is the relative molecular mass of the gas? A 19.3 B 21.0 C 28.0 D 47.1 6 In a calorimetric experiment conduct ed at standard conditions, 1.60 g of fuel underwent complete combustion. The reac tion was 45 % efficient in heating 200 g of water. The temperature of the water rose to 73 C. Given that the specific heat capacity of water is 4.2 J g –1 K–1, what is the total energy released per gram of fuel burnt? A 18.1 kJ g-1 B 40.3 kJ g-1 C 56.0 kJ g-1 D 85.2 kJ g-1 7 Under standard conditions, solid iodine slowly sublimes into a violet gas. Data for each form of iodine is given in the table. Hf  / kJ mol–1 S / J K–1 mol–1 I2 (s) 0 116 I2 (g) 62.4 261 What is the value of G in kJ K–1 mol–1, for the formation of gaseous iodine from solid iodine at 25 °C? A –15.4 B +19.2 C +27.8 D +106 P / kPa 60.8 0 1290 (1 / V) / m–3 6

5 H2 Chemistry 9647/01 NYJC J2/2013 Prelim [Turn over 0 0 0 0 8 The decomposition of hydrogen peroxide is known to be a first order reaction. 2H2O2  2H2O + O2 The rate constant is found to be 4.95 x 10 –2 min–1. If the initial concentration of H2O2 is 4.0 mol dm–3, what will be the concentration of H2O2 after 42 min? A 0.5 mol dm–3 B 1.0 mol dm–3 C 0.25 mol dm–3 D 2.0 mol dm–3 9 Which curve is obtained if the rate of reaction is plotted against time for an autocatalytic reaction (i.e. a reaction in which one of the products catalyses the reaction)? A B C D 10 Consider the following equilibrium. 3Y2(g) + 2XY(s) ⇌ 2XY4(g) When 3 mol of XY 4 was heated in a 2 dm 3 container, the equilibrium mixture contained 0.8 mol of XY. What is the numerical value of the equilibrium constant, K c? A 0.0286 B 0.179 C 5.60 D 35.0 7

6 H2 Chemistry 9647/01 NYJC J2/2013 Prelim 11 Use of the Data Booklet is relevant to this question. Ammonia can be synthesised directly using a mixture of hydrogen gas and nitrogen gas in a reversible reaction as shown: 3H 2(g) + N2(g) ⇌ 2NH3(g) Which one of the followi ng describes the change in yield of ammonia at equilibrium as temperature increases? A B C D 12 Given that a 0.500 mol dm -3 of HNO 2 solution has a K a value of 7.1 x 10 –4, calculate the percentage of undissociated HNO2 molecules. A 1.88 % B 3.77 % C 96.2 % D 98.1 % Temperature Yield Temperature Yield Temperature Yield Temperature Yield 8

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8 H2 Chemistry 9647/01 NYJC J2/2013 Prelim 15 During electrolysis under suitable conditi ons, 0.785 g of chro mium is deposited on the cathode when a current of 5.0 A is passed into a chromium-containing electrolyte for 9.7 min. What could the electrolyte be? A CrC l2 B CrC l3 C K2CrO3 D K2CrO4 16 Which of the following statements is correct? A The ionic radius of Na + ion is greater than that of Cl– ion. B The electronegativity of phosphorus is greater than that of nitrogen. C The first ionisation energy of magnes ium is less than that of aluminium. D The energy required to remove an electron from F – is less than that for Ne atom. 17 Which graph represents the volume of gas collected when separate 1.0 g samples of powdered magnesium car bonate and powdered barium carbonate are heated at the same temperature? A B C D Volume of gas / cm3 Time