2024 Prelims JPJC H2 Chem P1 (QP)

© Jurong Pioneer Junior College [Turn Over NAME CLASS 23S JURONG PIONEER JUNIOR COLLEGE JC2 PRELIMINARY EXAMINATION 2024 CHEMISTRY 9729/01 Higher 2 Paper 1 Multiple Choice Questions 16 September 2024 1 hour Candidates answer on the Question paper. 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, class and exam index 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 or 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 booklet. The use of an approved scientific calculator is expected, where appropriate. This document consists of 12 printed pages.

2 © Jurong Pioneer Junior College 9729/01/J2 PRELIM EXAM/2024 [Turn Over 1 Which statement about relative atomic mass is correct? A It is the average of the masses of all the isotopes of that element. B It is the sum of the relative masses of the neutrons and protons in each atom. C It is the ratio of the average mass of one atom of an element to the mass of one 1H atom. D It is the ratio of the mass of one mole of atoms of an element to one-twelfth the mass of one mole of 12C atoms. 2 The ionisation energies, IE, in kJ mol-1, of five elements are given in the table. element 2nd ionisation energy / kJ mol-1 3rd ionisation energy / kJ mol-1 4th ionisation energy / kJ mol-1 F 3370 6040 8410 Ne 3950 6150 9290 Na 4560 6940 9540 Mg 1450 7740 10500 Al 1820 2740 11600 Which statement about these ionisation energies is correct? A The 2nd IE of F is greater than the 3rd IE of Al because Al2+ ions have more outer shell electrons than F+ ions. B The 3rd IE of all the elements in the table involves the removal of an electron from the same shell. C The 4th ionisation energy of Na is greater than the 3 rd IE of Ne because the nuclear charge of Na is greater than that of Ne. D The successive ionisation energies of these elements increase as these electrons are being taken from the same shell. 3 Why is the molecule of BCl3 planar, whereas the molecule of PH3 is pyramidal? A The boron atom has no d-orbitals available for bonding. B The covalent radius of chlorine is greater than that of hydrogen. C The repulsion between chlorine atoms is greater than that between hydrogen atoms. D The boron atom in BCl3 has six electrons in its valence shell, whereas the phosphorus atom in PH3 has eight.

3 © Jurong Pioneer Junior College 9729/01/J2 PRELIM EXAM/2024 [Turn Over 4 After an oil spillage at sea, a liquid hydrocarbon layer floats on the surface of the water. Which statements help to explain this observation? 1 Hydrocarbon molecules are not solvated by water. 2 There are only instantaneous dipole −induced dipole interactions between hydrocarbon molecules. 3 Hydrogen bonding between water molecules causes water molecules to be packed closely together. A 2 only B 1 and 2 only C 2 and 3 only D 1, 2 and 3 5 Which diagram correctly describes the behavior of a fixed mass of an ideal gas at constant T (measure in K)? A B C D 6 A mixture of the three gases, oxygen, nitrogen and argon, is at a total pressure of 500 kPa. There is a total of 1.2 moles of gases in the mixture. If the oxygen gas alone occupied the entire volume of the mixture, it would exert a pressure of 150 kPa. At room conditions , the amount of nitrogen gas in the mixture would occupy a volume of 5.76 dm3. Using the data from above, what is the partial pressure of the argon gas in the mixture? A 150 kPa B 200 kPa C 250 kPa D 300 kPa V 0 pV V 0 density p 0 p 0

4 © Jurong Pioneer Junior College 9729/01/J2 PRELIM EXAM/2024 [Turn Over 7 When aqueous ammonia is added to a solution containing hexaaquairon( III) ions, [Fe(H2O)6]3+, a red -brown precipitate is formed which does not dissolve when excess ammonia is added. Which of the following states the role of ammonia in this reaction? 1 Brønsted-Lowry base 2 Ligand 3 Lewis acid 4 Reducing agent A 1 only B 4 only C 1 and 2 only D 2 and 3 only 8 Use of the Data Booklet is relevant to this question. An element M can exist in a few oxidation states. 15.00 cm 3 of an aqueous solution of 0.100 mol dm −3 of Mn+ required 20.00 cm 3 of 0.0250 mol dm−3 of acidified K2Cr2O7 solution for a complete reaction. What is the change in oxidation state of M? A 2 B 3 C 4 D 5 9 A sample of the hydrocarbon C 6H12 is completely burned in excess dry oxygen and the gaseous products collected as shown. The increases in mass of the collecting vessels P and Q are MP and MQ respectively. What is the ratio of MP / MQ? A 0.41 B 0.82 C 1.2 D 2.4 concentrated NaOH(aq) gaseous products

5 © Jurong Pioneer Junior College 9729/01/J2 PRELIM EXAM/2024 [Turn Over 10 Use of the Data Booklet is relevant to this question. A butane burner is used to heat water. The Mr of butane is 58. • Hc of butane is –2877 kJ mol–1. • 250 g of water is heated from 12 °C to 100 °C. • The burner transfers 47% of the heat released from the burning fuel to the water. Assume that the butane undergoes complete combustion and none of the water evaporates. What is the minimum mass of butane that must be burnt? A 0.071 g B 1.85 g C 3.94 g D 4.48 g 11 Hydrogen can be made from steam. H2O(g) + C(s) → H2(g) + CO(g) The Gibbs free energy change of reaction at two different temperatures are shown. G1 = +78 kJ mol−1 at 378K G2 = −58 kJ mol−1 at 1300K Which row of the table gives the correct signs of H and S for this reaction? H S A − − B − + C + − D + +

6 © Jurong Pioneer Junior College 9729/01/J2 PRELIM EXAM/2024 [Turn Over 12 One mol of neon gas at temperature T1 was added to another one mol of neon and the temperature was increased to T2. Which of the following diagrams correctly represents the Boltzmann distribution of molecular speeds before and after the changes were made? A B C D 13 The trends in two physical properties of the elements Na, Mg, A l, Si, P and S are shown in the following graphs. Which of the following illustrates the correct physical property for the corresponding graphs above? Graph 1 Graph 2 A melting point 1st ionisation energy B melting point electrical conductivity C 1st ionisation energy electrical conductivity D 1st ionisation energy melting point T2 molecular speed proportion of molecules T1 Graph 1 Graph 2 T1 molecular speed proportion of molecules T2 T1 molecular speed proportion of molecules T2 T1 molecular speed proportion of molecules T2

7 © Jurong Pioneer Junior College 9729/01/J2 PRELIM EXAM/2024 [Turn Over 14 Which of the following statements are correct for a system at dynamic equilibrium? 1 The rate of both forward and backward reaction is the same. 2 The concentration of reactants is equal to the concentration of products. 3 The rate constant of forward reaction is equal to the rate constant of the backward reaction. A 1 only B 1 and 2 only C 1 and 3 only D 1, 2 and 3 only 15 The graph shows the result of an investigation of the initial rate of hydrolysis of maltose by the enzy