RI 2019 Year 5 CT QP

RAFFLES INSTITUTION 2019 YEAR 5 TERM 3 COMMON TEST Higher 2 CHEMISTRY 9729 5 July 2019 2 hours 15 minutes Additional Materials: Multiple Choice Answer (OMR) Sheet Writing Paper Data Booklet READ THESE INSTRUCTIONS FIRST Write your name, index number and civics tutorial group in the spaces provided on the OMR Sheet, the cover sheets on pages 11 and 13, and the writing paper used for Section C. Do not use staples, paper clips, highlighters, glue or correction fluid. This paper consists of three sections, A, B and C. Section A (15 marks) Answer this section first. The OMR sheet will be collected after the first 30 minutes. There are fifteen questions in this section. 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 OMR Sheet. Read the instructions on the OMR 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 the question paper. Section B (30 marks) There are three questions in this section. Answers to this section are to be written in the spaces provided in the question paper. Section C (35 marks) There are two questions in this section. Answers to this section are to be written on the writing paper provided. You are to begin each question on a fresh sheet of paper. Write in dark blue or black pen. You may use a pencil for any diagrams or graphs. You are reminded of the need for good English and clear presentation in your answers. At the end of the examination, fasten your answers to Section C securely together. Answers to Sections A, B and C are to be handed in separately. The number of marks is given in brackets [ ] at the end of each question or part question. This document consists of 20 printed pages and 1 blank page. This document is copyrighted, please do not reproduce it without permission

2 © Raffles Institution 2019 9729/J/19 [Turn Over Section A (15 marks) For each question, there are four possible answers, A, B, C, and D. Choose the one you consider to be correct. 1 Use of the Data Booklet is relevant to this question. A sample of boron contains sodium as the only impurity. The information in the table was obtained by mass spectrometry of the sample. mass number 10 11 23 % abundance 15.52 74.48 10.00 What is the Ar of boron in the sample? A 9.74 C 12.04 B 10.83 D 13.08 2 Under acidic conditions, V2O5 undergoes a redox reaction with Fe2+. The products are Fe3+, water and a vanadium-containing species. Given that the mole ratio of V 2O5 to Fe2+ is 1 : 2, what could be the vanadium -containing species formed in the reaction? A V C VO2 B VO D V2O3 3 Beams of charged particles are deflected by an electric field. In an experiment, protons are deflected by an angle of +15 o. In another similar experiment under identical conditions, particle Z is deflected by an angle of –5o. What could be the composition of particle Z? proton neutron electron 1 1 0 4 2 1 2 2 3 3 3 1 4 3 3 5 A 2 and 3 C 3 and 4 B 2 and 4 D 1, 3 and 4 This document is copyrighted, please do not reproduce it without permission

3 © Raffles Institution 2019 9729/J/19 [Turn Over 4 Use of the Data Booklet is relevant to this question. The graph shows the logarithm, lg, of the first eight ionisation energies of two elements with atomic numbers less than 18. number of electrons removed What is the most likely compound that will be formed between the two elements? A CS2 C AlCl3 B SiO2 D NO2 5 X and Y are elements found in Period 2 of the Periodic Table, with proton numbers n and (n+1) respectively. The ion of X has a charge of +1, and the ion of Y is isoelectronic with the ion of X. Which statement correctly describes X and Y? A X and Y are isotopes. B X has a higher electronegativity than Y. C X and Y have the same electronic configuration. D The ion of Y has a higher charge density than the ion of X. 6 Which molecule has a greater number of  bonds than σ bonds? A CO2 C N2 B HCN D NO2 1 2 3 4 5 6 7 8 lg (ionisation energy) This document is copyrighted, please do not reproduce it without permission

4 © Raffles Institution 2019 9729/J/19 [Turn Over 7 Which pairs of compounds have the same shape around the underlined atom? 1 BCl3 and AlCl3 2 CO2 and SiO2 3 H2O and SO2 A 1 and 2 C 2 and 3 B 1 and 3 D 1, 2 and 3 8 Which statement best describes polar compounds? A Polar compounds are always soluble in water. B Compounds containing polar bonds must be polar. C A stream of a polar compound can be deflected by a charged rod. D A polar compound experiences only one type of intermolecular force. 9 Some ionic compounds have very low melting points and are liquids at temperatures below 100 °C. They are commonly referred to as ionic liquids. 1-propyl-3-methylimidazolium chloride is one such example. It has a melting point of 60 °C. Which statements are applicable to this compound? 1 It can form hydrogen bonds with itself. 2 It can form ion-dipole interactions with water. 3 The magnitude of its lattice energy is small because of the large cationic radius. A 1 and 2 C 2 and 3 B 1 and 3 D 1, 2 and 3 This document is copyrighted, please do not reproduce it without permission

5 © Raffles Institution 2019 9729/J/19 [Turn Over 10 Which diagram correctly describes the behaviour of a fixed mass of an ideal gas? (T is measured in K) A C B D 11 Which gas behaves most ideally at room temperature and pressure? A neon B chlorine C ammonia D carbon dioxide 12 Which equations correspond to the enthalpy change stated? 1 Br2(l) ⎯→ 2Br(g) ∆Hatom(Br2(l)) 2 C(s) + O2(g) ⎯→ CO2(g) ∆Hc(C(s)) 3 2H2(g) + O2(g) ⎯→ 2H2O(l) ∆Hf(H2O(l)) A 2 only C 1 and 3 B 1 and 2 D 1, 2 and 3 0 V T constant p 0 p V constant T 0 p pV constant T 0 density T constant p This document is copyrighted, please do not reproduce it without permission

6 © Raffles Institution 2019 9729/J/19 [Turn Over 13 Thermal decomposition of MgCO3 happens only at high temperatures. Which row correctly describes the signs of ∆H and ∆S for this thermal decomposition? ∆H ∆S A − − B − + C + − D + + 14 Using the information given in the table, what is the standard enthalpy change of reaction for the following reaction? NH3(g) + 3Cl2(g) ⎯→ 3HCl(g) + NCl3(l) compound ∆Hf / kJ mol−1 NH3(g) −45.9 HCl(g) −92.3 NCl3(l) +230.0 A −1.0 kJ mol−1 C −183.6 kJ mol−1 B +1.0 kJ mol−1 D +183.6 kJ mol−1 15 1.20 g of compound P undergoes complete combustion in excess oxygen to form 1.76 g of carbon dioxide and 0.72 g of water only. What is the empirical formula of P? A CH C CH2 B CHO D CH2O This document is copyrighted, please do not reproduce it without permission

7 © Raffles Institution 2019 9729/J/19 [Turn Over Section C (35 marks) Answe