2022 YIJC H2 CHEM PRELIM P1 QP

©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 14 September 2022 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 Use of the Data Booklet is relevant to this question. The table shows the fifth, sixth, seventh, eighth and ninth ionisation energies of an element in the third period. 5th 6th 7th 8th 9th ionisation energy / kJ mol−1 6270 21270 25430 29870 35920 Which element has these ionisation energy values? A P B S C Cl D Ar 2 Two elements X and Y have the following properties: • X and Y form ionic compounds Na2X and Na2Y respectively. • Element Y forms YF6 molecule whereas X is not able to do so. Which pair of electronic configurations for X and Y is correct? X Y A [He] 2s2 2p4 [He] 2s2 2p2 B [He] 2s2 2p2 [He] 2s2 2p6 3s2 3p3 C [He] 2s2 2p2 [He] 2s2 2p6 3s2 3p2 D [He] 2s2 2p4 [He] 2s2 2p6 3s2 3p4

©YIJC [Turn over 3 3 Use of the Data Booklet is relevant to this question. An element G forms an ionic nitrate with formula G(NO3)2. In a sample of this compound, the ion G contains 80 electrons and 126 neutrons. Which row describes: • the Group where G is found, • the nucleon number of G in this sample? Group nucleon number A 2 204 B 2 208 C 14 204 D 14 208 4 The table identifies the shape and polarity of four molecules. Which rows are correct? molecule molecular shape polarity 1 beryllium chloride bent non-polar 2 nitrogen dioxide bent polar 3 sulfur trioxide trigonal planar non-polar 4 chlorine trifluoride trigonal planar polar A 1, 3 and 4 B 2 and 3 C 2, 3 and 4 D 3 and 4

©YIJC [Turn over 4 5 Hydrazine, N2H4, and hydrogen peroxide, H2O2, are both used as rocket propellants because they can produce large volumes of hot gases from a small volume of liquid. Which statements about these two compounds are correct? 1 The bond angle in N2H4 is larger than that in H2O2. 2 The N-H bond is shorter than the O-H bond. 3 N2H4 forms stronger intermolecular hydrogen bonds than H2O2. 4 There are  bonds formed by sp3–s orbital overlap in both molecules. A 1 and 4 B 2 and 3 C 1, 2 and 4 D 1, 3 and 4 6 In an experiment, 0.100 g of a volatile liquid Q formed 0.0250 dm 3 of vapour at 100 ⁰C at 1 bar. What is the relative molecular mass of Q? A 0.100 × 373 0.0250 × 22.7 B 0.0250 × 273 × 22.7 0.100 × 373 C 0.100 × 273 × 22.7 0.0250 × 373 D 0.100 × 373 × 22.7 0.0250 × 273 7 For the elements in Group 17, which trends down the Group are correct? volatility oxidising power A decreases decreases B decreases increases C increases decreases D increases increases

©YIJC [Turn over 5 8 Which statement about relative molecular mass is correct? A It is the sum of the relative atomic masses of all the atoms within the molecule. B It is the ratio of the average mass of a molecule to the mass of a 12C atom. C It is the ratio of the mass of 1 mol of molecules to the mass of 1 mol of 1H atoms D It is the average mass of all the atoms within the molecule. 9 The enthalpy change of reaction 1 is –114 kJ mol−1. 2NaOH(aq) + H2SO4(aq) → Na2SO4(aq) + 2H2O(l) reaction 1 By using this information, what is the most likely value for the enthalpy change of reaction 2? NaOH(aq) + CH3COOH(aq) → CH3COONa(aq) + H2O(l) reaction 2 A −50 kJ mol−1 B −57 kJ mol−1 C −114 kJ mol−1 D −228 kJ mol−1 10 Which equations represent standard enthalpy changes at 298 K? 1 H2(g) + F2(g) → 2HF(g) 2 CH4(g) + 2O2(g) → CO2(g) + 2H2O(g) 3 ½F2(g) → F(g) A 1 and 3 B 2 and 3 C 2 only D 3 only 11 Melphalan is a drug used to treat infections. The breakdown of melphalan in the blood is a first -order reaction. An original concentration of melphalan of 15.00 mg dm−3 decreases to 1.875 mg dm−3 after 270 minutes. What is the time taken, in minutes, for the concentration of melphalan to decrease from 10.0 mg dm−3 to 2.00 mg dm−3 in the blood? A 105 B 180 C 209 D 360

©YIJC [Turn over 6 12 The reaction between NO2 and CO to produce NO and CO2 is thought to occur in two steps: step 1: NO2 + NO2 NO + NO3 step 2: NO3 + CO CO2 + NO2 Which statements are correct? 1 The rate constant has units of mol−2 dm6 s–1. 2 NO2 is a catalyst. 3 The rate of reaction is independent on the concentration of CO. A 1, 2 and 3 B 2 and 3 C 1 and 2 D 1 only 13 Each of the following equilibria is subjected to two changes which are carried out separately: • the pressure is reduced at constant temperature; • the temperature is increased at constant pressure. Which equilibrium will both changes result in an increase in the proportion of products? A H2(g) + I2(g) ⇌ 2HI(g) H = +53 kJ mol−1 B 4NH3(g) + 5O2(g) ⇌ 4NO(g) + 6H2O(g) H = −950 kJ mol−1 C N2(g) + 3H2(g) ⇌ 2NH3(g) H = −92 kJ mol−1 D N2O4(g) ⇌ 2NO2(g) H = +57 kJ mol−1 14 At 25 C, Kw = 1.00 x 10−14 mol2 dm−6. At 62 C, Kw = 1.00 x 10−13 mol2 dm−6. Which row is correct? the ionisation of water is at 62 C, water with a pH of 7.0 is A endothermic alkaline B endothermic neutral C exothermic alkaline D exothermic neutral slow

©YIJC [Turn over 7 15 Lysine is an essential amino acid found in the body. It has three p Ka values associated with it. CO2H NH2 H (CH2)4NH2 lysine The pH curve below is obtained when one mole of the protonated lysine is titrated with hydroxide, OH−, ions. At which point on the graph does pH = pKa1 where Ka1 is the first acid dissociation constant of lysine? 0 0 0.5 1.0 1.5 2.0 2.5 3.0 pH B D C number of moles of hydroxide added A

©YIJC [Turn over 8 16 Vehicles produce exhaust emissions when the engine is running. These emissions can include harmful pollutants such as carbon monoxide, oxides of nitrogen and unburnt hydrocarbons. A catalytic converter is used to change the gases emitted through chemical reactions. Which reactions between the stated compounds occur in the catalytic converter? 1 hydrocarbons + oxides of nitrogen → carbon dioxide + water + nitrogen 2 carbon monoxide + oxides of nitrogen → carbon dioxide + nitrogen 3 carbon monoxide + hydrocarbons → carbon dioxide + water A 1, 2 and 3 B 1 and 2 C 2 and 3 D 1 only 17 The Gabriel synthesis is a useful method of preparing primary amines. What are the types of reactions occurring in each of the steps? step 1 step 2 step 3 A acid-base electrophilic substitution hydrolysis B