YIJC 2023 H2 Chem Prelim P1 QP (1)

©YIJC [Turn over YISHUN INNOVA JUNIOR COLLEGE JC 2 PRELIMINARY EXAMINATION Higher 2 CANDIDATE NAME CG INDEX NO CHEMISTRY Paper 1 Multiple Choice Additional Materials: Multiple Choice Answer Sheet Data Booklet 9729/01 15 September 2023 1 hour READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, highlighters, glue or correction fluid/tape. Write your name and class 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 booklet. The use of an approved scientific calculator is expected, where appropriate. This document consists of 16 printed pages.

©YIJC [Turn over 2 1 A medal has a total surface area of 150 cm2. It is evenly coated with silver by electrolysis. Its mass increases by 0.216 g. How many atoms of silver are deposited per cm2 on the surface of the medal? A 8.0 x 1018 B 1.8 x 1019 C 8.7 x 1020 D 1.2 x 1021 2 Which gas would behave most like an ideal gas under room conditions? A ammonia B helium C krypton D nitrogen 3 In two separate experiments a beam of protons and a beam of He2+ 2 4 particles, travelling at the same velocity, pass through an electric field as shown. Which statements are correct? 1 Both beams are deflected in the same direction. 2 The proton beam travels in a straight path towards the negatively charged plate. 3 The protons are deflected to a larger extent than the He2+ 2 4 particles. A 1 and 2 B 1 and 3 C 2 and 3 D 1 only

©YIJC [Turn over 3 4 The table shows some properties of four substances. Which substance could be potassium iodide? Melting point of solid / °C Electrical conductivity when molten A −66 poor B −39 good C 680 good D 1600 poor 5 A carbon monoxide molecule, CO, has three bonds between the carbon atom and the oxygen atom. Which features are present in one CO molecule? 1 Three lone pairs of electrons 2 A co-ordinate bond from oxygen to carbon 3 Two  bonds A 1 and 2 B 2 and 3 C 1 and 3 D 1, 2 and 3

©YIJC [Turn over 4 6 The reaction of manganate(VII) ions with ethanedioate ions in acid solution may be represented by the following equation. 2MnO4–(aq) + 16H+(aq) + 5C2O42–(aq) → 2Mn2+(aq) + 8H2O(l) + 10CO2(g) The graph shows concentration of manganate(VII) ions against time for this reaction. What does the shape of the graph suggest about this reaction? A The rate of reaction decreases with time. B The reaction is endothermic. C The reaction shows first order kinetics. D The reaction is catalysed by a product. [MnO4−] 0 time

©YIJC [Turn over 5 7 The graph shows the results of an investigation of the initial rate of hydrolysis of casein by the enzyme trypsin. In the experiments, the initial concentration of casein was varied but that of trypsin was kept constant. Which conclusions can be deduced from these results? 1 When [casein] is high, the rate is independent of [trypsin]. 2 When [casein] is high, the rate is independent of [casein]. 3 When [casein] is low, the rate is first order with respect to [casein]. A 1, 2 and 3 B 1 and 2 C 2 and 3 D 1 only initial reaction rate [casein] 0

©YIJC [Turn over 6 8 An equilibrium is set up, in a vessel at constant temperature and atmospheric pressure, according to the following reaction. 2NO2(g) ⇌ N2O4(g) The vessel is attached to a plunger which can alter the pressure inside the vessel. At a time t, the plunger is pushed in quickly to increase the pressure and an new equilibrium is established. The temperature is maintained constant throughout. Which graph shows the change in partial pressure of N2O4, pN2O4 , during this process? A B C D t time time t time t time t

©YIJC [Turn over 7 9 An experiment was conducted to determine the efficiency of the heating of a can of water using a spirit burner. The following data were recorded: Mass of ethanol burnt = m g Change in temperature of water = ∆T oC You are also given that: Relative molecular mass of ethanol = 46.0 Enthalpy change of combustion of ethanol = –1371 kJ mol−1 Specific heat capacity of water = c J g−1 K−1 Which expression below gives the efficiency of this heating process? A 300 × c × ∆T × 46.0 m × 1371 × 1000 × 100% B m × c × ∆T × 46.0 300 × 1371 × 1000 × 100% C 300 × c × ∆T × 46.0 m × 1371 × 100% D m × 1371 × 1000 300 × c × ∆T × 46.0 × 100% 10 The enthalpy changes involving some oxides of nitrogen are given below: enthalpy change / kJ mol–1 N2(g) + O2(g) → 2NO(g) +180 N2(g) + 5 2O2(g) → N2O5(g) +11 2NO2(g) + 1 2O2(g) → N2O5(g) –55 What is the enthalpy change, in kJ mol–1, of the following reaction? 2NO(g) + O2(g) → 2NO2(g) A –114 B +114 C –136 D +136 thermometer can containing 300 g of water burner containing ethanol

©YIJC [Turn over 8 11 The conversion of graphite into diamond is a non–spontaneous reaction at 298 K. The entropy change of this reaction is negative at 298 K. C(graphite) → C(diamond) G = +3.08 kJ mol–1, S = –3.3 J mol–1 K–1 With reference to the enthalpy change, H, of the reaction above, which statements are correct? 1 Enthalpy change of atomisation of diamond is less endothermic than that of graphite. 2 Enthalpy change of atomisation of diamond is more endothermic than that of graphite. 3 Enthalpy change of combustion of diamond is less exothermic than that of graphite. 4 Enthalpy change of combustion of diamond is more exothermic than that of graphite. A 1 and 3 B 1 and 4 C 2 and 3 D 2 and 4 12 Solid NaCl was continuously added to a 1 dm3 solution containing z mol of Ag+ ions and the amount of AgCl precipitated was found to change, as shown in the graph below. When x mol of NaCl was added, w mole of AgCl precipitate was formed. Which of the following gives the correct expression for the solubility product of AgCl? A (z)(y) B (w)(x) C (z)(x) D (y)(y) amount of AgCl precipitate / mol amount of NaCl added / mol x y w

©YIJC [Turn over 9 13 Two experiments were conducted. In the first set-up, 0.1 mol dm–3 of sodium ethanoate and 0.1 mol dm–3 silver nitrate was mixed and a white precipitate was obtained. On adding potassium bromide, the precipitate turns cream. In the second set -up, 0.1 mol dm –3 of silver nitrate was added to potassium bromide and a cream precipitate was obtained. On adding sodium ethanoate, there is no further change. What can be deduced from these observations? A The cream precipitate is due to the silver ethanoate. B Silver bromide is more soluble than silver ethanoate. C The white precipitate in the first se