JPJC 9729 Prelim P1

© Jurong Pioneer Junior College [Turn Over NAME CLASS 22S JURONG PIONEER JUNIOR COLLEGE JC2 PRELIMINARY EXAMINATION 2023 CHEMISTRY 9729/01 Higher 2 Paper 1 Multiple Choice Questions 19 September 2023 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/2023 1 Element X has eight more protons than element Y. Which statement must be correct? A Atoms of element Y are larger than atoms of element X. B Element X has at least one fully filled shell of electrons. C Element X and element Y are in the same group. D Element X and element Y are in the same period. 2 Molecular dimerisation can be described as the process in which two identical molecules combine to give a single product. Examples of dimers are: Al2Cl6 and (CH3CH2CO2H)2. Which statement about the above dimers is incorrect? A Two hydrogen bonds hold the CH3CH2CO2H molecules together in the dimer. B Each aluminium atom is surrounded by four chlorine atoms in the dimer, Al2Cl6. C CH3CH2CO2H exists as dimers when dissolved in water. D Al2Cl6 dimers are non-polar molecules. 3 Which statement is correct? A Cl has a relative isotopic mass of 35.5. B Cl2 has a relative molecular mass of 70. C ICl has a relative molecular mass of 162.4. D NaCl has a relative molecular mass of 58.5. 4 Use of the Data Booklet is relevant to this question. The most common scuba diving gas tank typically comprises 11.7% of helium gas, 56.2% of nitrogen gas and 32.1% of oxygen gas by volume. What is the mass of oxygen gas inside the diving gas tank of 0.018 m3 and 300 bar at 293K? A 1.14 kg B 2.28 kg C 7.10 kg D 7100 kg

3 © Jurong Pioneer Junior College 9729/01/J2 PRELIM EXAM/2023 [Turn Over 5 The following graph shows the behaviour of an ideal gas with fixed mass. Which of following will yield the graph above? X-axis Y-axis condition A p in Pa pV in Pa m3 constant temperature B p in Pa ρ (density) in g m−3 constant temperature C T in K V in m3 constant pressure D T in K 1 p in Pa−1 constant volume 6 Which description of Dalton’s Law is correct? A Equal volumes of gases at the same temperature and pressure contain equal numbers of molecules. B The partial pressure of a gas in a mixture is given by the product of its mole fraction and the total pressure. C The partial pressure of a gas in a mixture is given by the product of its percent by mass and the total pressure. D The total pressure of a mixture of gases is equal to the sum of the partial pressures of these gases. 7 When iodine is oxidised by nitric acid, a white crystalline solid iodine-containing oxide can be isolated from the mixture. 0.001 mole of this oxide reacts with 0.01 0 mole of acidified potassium iodide to give 0.006 mole of iodine, I2. What is the oxidation number of iodine in the oxide? A +1 B +3 C +5 D +7 Y X

4 © Jurong Pioneer Junior College 9729/01/J2 PRELIM EXAM/2023 8 Which statements are correct? 1 enthalpy change of combustion of H2 = enthalpy change of formation of H2O 2 enthalpy change of atomisation of H2 = bond energy of H−H 3 enthalpy change of solution of HCl = l− +enthalpy change of hyd aratio nd n H C of A 1 only B 1 and 2 only C 1 and 3 only D 1, 2 and 3 9 Use of Data Booklet is relevant to this question Carbon can exist naturally in two different crystalline forms, diamond and graphite. carbon (diamond) ⟶ carbon (graphite) Hꝋ = −1.9 kJ mol−1 Sꝋ = +3.4 J K−1 mol−1 Which statements are correct and explain why diamond does not change into graphite at room temperature and pressure? 1 The forward reaction has an extremely small rate constant. 2 Gꝋ is −2.9 kJ mol−1 for the above transformation. 3 The reverse reaction is spontaneous. A 1 only B 1 and 2 only C 2 and 3 only D 1, 2 and 3 10 The diagram shows the Boltzmann distribution for one mole of a gas. The gas takes part in a reaction with an activation energy, Ea. Which statement correctly describes the effect of an increase in temperature? A Peak Z will be higher and fewer molecules will have energy > Ea. B Peak Z will be higher and more molecules will have energy > Ea. C Peak Z will be lower and fewer molecules will have energy > Ea. D Peak Z will be lower and more molecules will have energy > Ea. number of particles kinetic energy / kJ mol−1 0 Z Ea

5 © Jurong Pioneer Junior College 9729/01/J2 PRELIM EXAM/2023 [Turn Over 11 Hydrogen peroxide solution decomposes. The equation for this reaction is shown. 2H2O2(aq) ⟶ 2H2O(l) + O2(g) A 100cm3 sample of hydrogen peroxide solution is warmed. After 80 minutes, 6.00 dm 3 of oxygen gas, measured at r oom temperature and pressure , is collected. Under these conditions, the reaction has a constant half-life of 40 minutes. What is the initial concentration of the hydrogen peroxide solution? A 0.66 mol dm−3 B 2.0 mol dm−3 C 3.3 mol dm−3 D 6.6 mol dm−3 12 A large excess of magnesium ribbon is added to dilute hydrochloric acid and the volume of hydrogen gas produced is measured as the reaction proceeds. The reaction is exothermic. The results are shown. Which row explains the changes in the rate of reaction between points P and Q and between points Q and R? between points P and Q between points Q and R A the reaction temperature is increasing the acid concentration is falling B the reaction temperature is increasing the magnesium has been used up C magnesium’s surface area is decreasing the acid concentration is falling D magnesium’s surface area is decreasing the magnesium has been used up total volume / cm3 time / s P Q R

6 © Jurong Pioneer Junior College 9729/01/J2 PRELIM EXAM/2023 13 The variation of the ionic product of water, Kw, with temperature is given in the table. Temperature / oC Kw / mol2 dm−6 0 1.14 x 10−15 25 1.00 x 10−14 50 5.50 x 10−14 What can be deduced from this information? A [H+] is more than [OH−] as temperature increases. B pH of water at 50 oC is higher than that at 25 oC. C As temperature increases, more water ionises. D The ionisation of water is an exothermic process. 14 Which row correctly describes the species in terms of its behaviour as a Lewis base and as a BrØnsted-Lowry acid? species Lewis base BrØnsted- Lowry acid A CH3OH 🗸 🗸 B NH4+ 🗶 🗶 C OH− 🗶 🗶 D O2− 🗶 🗸 15 Use of the Data Booklet is relevant to this question. Natural water in reservoirs often contains very finely divided solid particles of between 1 and 100 nm in diameter which have negative charges on their surface. One stage in purifying the water consists of adding salt solutions containing high charge density cations which neutralise the negative charges and cause the solid participles to join together and settle out. Which com