2020 EJC JC2 Prelim H2 Chemistry Paper 1 QP

© EJC [Turn Over EUNOIA JUNIOR COLLEGE JC2 Preliminary Examination 2020 General Certificate of Education Advanced Level Higher 2 CHEMISTRY Paper 1 Multiple Choice 9729/01 18 September 2020 1 hour Additional Materials: Multiple Choice Answer Sheet Data Booklet READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, glue or correction fluid. Write your name, civics group and registration number on the Answer Sheet in the spaces provided unless this has been done for you. 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 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 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. This document consists of 11 printed pages and 1 blank page.

2 © EJC 9729/01/J2PE/20 1 Which of the following species will produce the largest deflection when fired with equal velocity into an electric field? A 7Li+ B 9Be2+ C 16O2– D 14N3– 2 Use of the Data Booklet is relevant to this question. Which of the following statements are true? 1 The Cr atom has an empty d-orbital. 2 All the electrons in the d-orbitals of a Mn2+ ion are unpaired. 3 The Fe2+ ion has the same electronic configuration as the Co3+ ion. A 1, 2 and 3 B 1 and 2 C 2 and 3 D 1 only 3 Which of the following contains one polar molecule and one non-polar molecule? A AlCl3, Al2Cl6 B POCl3, PCl3 C HOBr, Br2O D XeF2, XeF6 4 Which of the following statements about Al2O3 are true? 1 It can react with both acids and bases. 2 It has a higher degree of covalent character than Na2O. 3 It has a more exothermic lattice energy as compared to Na2O. A 1, 2 and 3 B 1 and 2 C 2 and 3 D 1 only

3 © EJC 9729/01/J2PE/20 [Turn over 5 Use of the Data Booklet is relevant to this question. The following graph was obtained for a sample of a gas at 500 K. Assuming that the gas behaves ideally under the conditions at which all measurements were made, what is its likely identity? A He B Ne C Ar D Kr 6 Which of the following statements about a 20.3 g sample of Co 2(SO4)3 (Mr = 406) is incorrect? A It contains 1.5 × 1023 ions. B It contains 0.1 mol of Co3+ ions. C It contains 14.5 % of cobalt by mass. D It contains 47.3 % of oxygen by mass. 7 20.0 cm 3 of 0.02 mol dm –3 aqueous sodium bromate( V), NaBrO 3, was found to react completely with 80.0 cm3 of 0.01 mol dm–3 hydroxylamine, NH2OH. The half equation for the reduction of bromate(V) ion is given as shown. 32BrO (aq) + 6H (aq) + 6 Br (aq) + 3H O( )e      l Which of the following could be the nitrogen-containing product in this reaction? A NO B 2NO C 2NO D 3NO 0 1 2 3 0 0.5 1 1.5 pressure / bar density / g dm−3

4 © EJC 9729/01/J2PE/20 8 Sublimation is the process of changing a solid into a gas without passing through the liquid phase. Which statements correctly describe the standard enthalpy change of sublimation? 1 The standard enthalpy change of sublimation of a metal is the same as its standard enthalpy change of atomisation. 2 The standard enthalpy change of sublimation is given by the sum of the standard enthalpy change of fusion (solid to liquid) and the standard enthalpy change of vapourisation (liquid to gas). 3 Xenon does not possess a standard enthalpy change of sublimation since xenon is a gas under standard state. A 1 only B 1 and 3 only C 2 and 3 only D 1, 2 and 3 9 Consider a hypothetical reaction        A g 2B g 3C s D g    rH 0 Which statement about the standard Gibbs free energy change of reaction, rG , is correct? A rG is always positive. B rG is always negative. C rG can be zero. D rG can never be zero.

5 © EJC 9729/01/J2PE/20 [Turn over 10 E and F undergo a bimolecular elementary reaction   E F G When equal concentrations of E and F are reacted together, which of the following graphs would be obtained? A B C D 11 The following steps illustrate the decomposition of hydrogen peroxide to produce oxygen when the strong acid, HBr(aq) is added. Step I: + 3222 23H O (aq) H O (aq) (aq) ( H O H O )   l + 32 c + 2 2 3 [H O ] [H O ][H O ]K  Step II: 3 2 2H O (aq) Br (aq) HOBr(aq) H O( )      l Step III: 2 2 3 2HOBr(aq) H O (aq) H O (aq) O (g) Br (aq)     Experimental studies performed to investigate the kinetics of the reaction showed that the rate could be stated as  2 2 3rate H O H O Brk       What can be deduced from the above information? 1 Step III is the rate-determining step. 2 HBr(aq) served as the catalyst for the decomposition. 3 The decomposition of hydrogen peroxide is a pseudo-first order reaction. A 1 only B 1 and 2 C 2 and 3 D 1, 2 and 3 [G] t [G] t [E][F] t [E][F] t

6 © EJC 9729/01/J2PE/20 12 Consider the following equilibrium      3 2 22NH g N g 3H g  H 193 kJ mol Which of the following change will not cause the rate of backward reaction to increase? A Adding a catalyst. B Decreasing the volume of the vessel. C Increasing the temperature. D Removing gaseous NH3. 13 Consider the following equilibrium ( ) ( )2 4 2N O g 2NO g 0.24 atm of N2O4(g) was allowed to decompose in a 100 dm3 container at 298 K. After the system reached equilibrium, it was found that the total pressure was 0.32 atm. Assuming that all the gases behave ideally under the stated conditions, what is the equilibrium partial pressure of N2O4(g)? A 0.08 atm B 0.11 atm C 0.12 atm D 0.16 atm 14 Which of the following aqueous solutions will considerably change in pH when relatively small volumes of strong acid or strong alkali are added? A A mixture of sodium benzoate and benzoic acid B A mixture of ammonium sulfate and aqueous ammonia C A mixture of potassium chloride and potassium ethanoate D A mixture of sodium carbonate and sodium hydrogencarbonate 15 A sparingly soluble aluminium salt ionises in aqueous solution according to the following equation. 3+ 3 A Y (s) A (aq) 3Y (aq)  ll Given that the solubility product of AlY3 is K, what is the concentration of Y– (aq) in terms of K at equilibrium? A 1 2()K B 1 23( )K C 1 4(3 )K D 1 4 27   K

7 © EJC 9729/01/J2PE/20 [Turn over 16 Use of the Data Booklet is relevant to this question. The colours of various vanadium ions in aqueous solution are given in the table below. oxidation state of V +5 +4 +3 +2 ion + 2VO 2VO  3V  2V  colour yellow blue green violet What is the final colour of the solution when excess zinc powder is added to an acidified solution containing + 2VO ions? A violet B green C blue D yellow 17 Use of the Data Booklet is relevant to this question. An antique car bumper is to be chrome plated. The bumper is dipped into an acidic Cr2O72 solution where it serves as an electrode of an electrolytic cell. Oxygen is formed at the other electrode. Which one of the following statements is correct? A Reduction of water occurs to form oxygen. B The bumper is the anode of the electrolytic cell. C For every 52 g of chromium plated, 3 mol of oxygen gas are evolved. D It takes about 16 hours to plate 52 g of chromium, if the current used is 10 A. 18 The standard redox potentials of some manganese species are shown below. E /V 2 Mn (aq) 2e Mn(s)  −1.18 3 22MnO (s) 4H (aq) e Mn (aq) 2H O( )     l +0.95 3 2Mn (aq) e Mn (aq)    +1.54 Given that the reactions are