2021 EJC Prelims Paper 1 QP

© EJC [Turn Over EUNOIA JUNIOR COLLEGE JC2 Preliminary Examination 2021 General Certificate of Education Advanced Level Higher 2 CHEMISTRY Paper 1 Multiple Choice 9729/01 23 September 2021 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 10 printed pages.

2 © EJC 9729/01/J2PE/21 1 Which electronic configuration represent s an atom of an element, at ground state, that forms a stable ion with a charge of +3? A 1s2 2s2 2p3 B 1s2 2s2 2p6 3s2 3p1 C 1s2 2s2 2p6 3s2 3p6 D 1s2 2s2 2p6 3s2 3p6 3d2 4s1 2 Which particle has more protons than electrons and more protons than neutrons? ( ) 2 1DH= A H3O+ B D3O+ C D2O D OH– 3 Gaseous particle R has a proton number n and forms a stable monoatomic ion of charge ‒1. Gaseous particle S has a proton number of ( n+2) and it forms a stable monoatomic ion which is isoelectronic with the ion of R. Which of the following statement is correct? A Ion of S has a smaller ionic radius than ion of R. B Ion of R releases more energy than ion of S when an electron is added to each particle. C R has a larger atomic radius than S. D Ion of S requires less energy than ion of R when an electron is removed from each particle. 4 In a single covalent bond, one pair of electrons is shared by two atoms. Which of the following statement is true for all single covalent bonds? A Covalent bonds are formed when bonding electrons are shared equally between two atoms. B Covalent bonds allow the atoms involved to complete their outer electron shell configuration. C Covalent bonds formed between atoms of different electronegativities are stronger. D Covalent C−H bonds formed between sp3 hybridised C and H atoms are weaker than that formed between sp2 hybridised C and H atoms.

3 © EJC 9729/01/J2PE/21 [Turn over 5 Cinnamaldehyde occurs naturally in cinnamon oil. Which of the following statements are true about the structure? 1 Hydrogen bonds can be formed between cinnamaldehyde molecules. 2 Cinnamaldehyde dissolves in organic solvents readily via instantaneous dipole−induced dipole interactions. 3 The bond angles about all carbon atoms in cinnamaldehyde are the same. A 1, 2 and 3 B 2 and 3 C 3 only D none of the above 6 Which of the following statements about Group 17 elements is true? A I2 can reduce S2O32− to S4O62−. B When Br2(g) is bubbled into NaCl(aq), an orange solution is produced. C Cl2 is soluble in water as it can form favourable hydrogen bonds with water. D F2 is more volatile than Br2 as the F−F bonds are weaker than the Br−Br bonds. 7 Which of the following pairs of reactants cannot undergo an acid-base reaction together? A NH3 and H2O B NH3 and BH3 C AlCl3 and Cl2 D AlCl3 and BH3 8 Which of the following quantities is equal to the Avogadro constant? A The number of atoms in 24 dm3 of oxygen under room temperature and pressure. B The number of molecules in 1 dm3 of chlorine at 273 K and 1.5 atm. C The number of ions in 68.05 g of CaSO4. D The number of carbon atoms in 22.7 dm3 of ethane gas under standard temperature and pressure.

4 © EJC 9729/01/J2PE/21 9 The following graphs show the variation of three properties of consecutive Period 3 elements. Graph 1 Graph 2 Graph 3 What properties are shown by the three graphs? Graph 1 Graph 2 Graph 3 A pH of chloride pH of oxide melting point of element B pH of chloride melting point of element pH of oxide C pH of oxide melting point of element pH of chloride D pH of oxide pH of chloride melting point of element 10 The conversion of white phosphorus to phosphorus atoms is shown. Hr Which expression will give a correct value for the ∆Hr indicated above? A bond energy of P–P B enthalpy change of atomisation of phosphorus C enthalpy change of formation of phosphorus D enthalpy change of vaporisation of phosphorus Na Mg Al Si P Na Mg Al Si P Na Mg Al Si P

5 © EJC 9729/01/J2PE/21 [Turn over 11 The conversion of graphite into diamond is non-spontaneous at 298 K. C(graphite) → C(diamond) ∆G = +3.08 kJ mol–1 ∆S = –3.3 J mol–1 K–1 Assuming ∆H and ∆S are constant with temperature, which of the following statements are correct? 1 The enthalpy change of combustion of diamond is more exothermic than that of graphite. 2 The bond energies of the C–C bonds in graphite and diamond are the same. 3 The reaction is more spontaneous with increasing temperature. A 1 only B 1 and 2 C 1 and 3 D 2 and 3 12 The reaction A + B → C + D has the rate equation, rate = k[A][B]. An experiment was conducted by reacting 0.001 mol dm−3 of A with 1.0 mol dm−3 of B. The half-life for this experiment was found to be 5 min. A second experiment was conducted with twice the concentrations of both A and B. What will be the half-life of the second experiment? A 1.25 min B 2.5 min C 5 min D 10 min 13 Which of the following statements about enzyme-catalysed reactions are true? 1 Enzymes lower the activation energy of the reaction. 2 When the concentration of substrate is low, rate is directly proportional to the concentration of substrate. 3 Rate will always increase when the concentration of substrate is increased. A 1, 2 and 3 B 1 and 2 C 2 and 3 D 1 only 14 The equilibrium constant of the reaction 2A B 2C+ at T ºC is x. What is the equilibrium constant of the reaction 1C A B 2+ at the same temperature? A 2− x B 1 2x C 1 x D x

6 © EJC 9729/01/J2PE/21 15 Consider a system comprising hydrogen, nitrogen and ammonia gas at equilibrium. 3H2(g) + N2(g)  2NH3(g) Which of the following statements about the system are true? 1 Decreasing the volume at constant temperature will increase the rates of both the forward and backward reactions. 2 Addition of a noble gas at constant pressure will not affect the position of equilibrium. 3 Addition of finely divided iron as catalyst increases the equilibrium constant of the reaction. A 1, 2 and 3 B 1 and 2 C 2 and 3 D 1 only 16 Calculate the pH of the resultant solution when 20 cm 3 of sodium hydroxide with concentration at 0.500 mol dm–3 are mixed with 20 cm3 of ethanoic acid with concentration of 1.00 mol dm–3. (Ka of ethanoic acid = 1.8 × 10–5 mol dm–3) A 2.37 B 2.61 C 4.74 D 9.13 17 The solubilities of AgCl and AgBr are x and y mol dm–3 respectively at 298 K. Which of the following statements are correct about a solution saturated with both AgC l and AgBr? 1 [Ag+] = x + y 2 [Br–] < y 3 [Ag+] = [Br–] + [Cl–] A 1, 2 and 3 B 1 and 2 C 1 and 3 D 2 and 3

7 © EJC 9729/01/J2PE/21 [Turn over 18 The structure of 2-methyl-N-phenylpropan-1-imine is shown. Which statement about 2-methyl-N-phenylpropan-1-imine is correct? A 2-methyl-N-phenylpropan-1-imine is optically active. B The C–N  bond is formed from an overlap between sp2 hybrid orbitals of C and N. C The nitrogen atom in 2-methyl-N-phenylpropan-1-imine is sp hybridised. D 2-methyl-N-phenylpropan-1-imine is less basic than ammonia. 19 Which compound is n