2019 NYJC Prelim P1 QP

[Turn Over This document consists of 19 printed pages. NANYANG JUNIOR COLLEGE JC 2 PRELIMINARY EXAMINATION Higher 2 CHEMISTRY 9729/01 Paper 1 Multiple Choice 23 September 2019 1 hour 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, CT and NRIC / FIN on the Answer Sheet in the spaces provided. There are thirty questions in 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.

2 H2 Chemistry 9729/01 NYJC J2/2019 PRELIM 1 4th July 2012, the discovery of th e Higgs boson validated the Standard Model of elementary particles, a widely accepted framework for understanding sub-atomic particles. In the Standard Model, nucleons can be further divided into more basic particles, called quarks. Quarks occupy spaces and have charges; some positive, some negative. The following table list the characteristics of some sub-atomic particles in the Standard Model. Type of particle Symbol Size and polarity of electronic charge, e Up quark u +⅔ Down quark d –⅓ electron e –1 neutrino ve 0 In a radioactive reaction, the following process occurs in the nucleus of an atom. nucleon A nucleon B Which of the following statements are correct? 1 The charge of nucleon B is +1. 2 Particle C is deflected towards the positive plate in an electric field. 3 The process can be described by 22Ne → 22Na. A 1, 2 and 3 B 1 and 2 only C 2 and 3 only D 1 only 2 An oxygen candle is used to provide an emergency supply of oxygen in spacecraft. It contains sodium chlorate in a chemical mixture. When ignited, the mixture burns at 600 °C. At this temperature, thermal decomposition of the sodium chlorate occurs, releasing oxygen gas and forming sodium chloride as the only products. When sodium chlorate decomposes, 0.150 moles of oxygen gas and 0.100 mole of sodium chloride are formed. What is the oxidation state of chlorine in the chlorate? A +3 B +5 C +6 D +11 u d d u u d + particle C + ve

3 H2 Chemistry 9729/01 NYJC J2/2019 PRELIM [Turn Over 3 Cations with a high charge density can polaris e adjacent anions. This results in ionic bonds with covalent character. However, if the oxidation state is high enough, a covalent bond will form instead. Which of the following correctly lists the most ionic and the most covalent halide compounds? Most ionic Most covalent A SnF2 PbCl4 B PbF2 SnCl4 C SnF4 PbCl2 D PbF4 SnCl2 4 Compound Z has the following structure. NN C NC O H O H compound Z Which bond angle is not present in a molecule of compound Z? A 105° B 109° C 120° D 180° 5 Use of the Data Booklet is relevant to this question. A mass of 0.253 g of a volatile liquid is injected into a gas syringe at 97 °C. The initial reading of the gas syringe, before the injection of the liquid, is 5 cm3. The final reading, after complete vaporisation of the liquid, is 81 cm3. The temperature was kept constant at 97 °C. Atmospheric pressure is 1 atm. What is the Mr of the volatile liquid? A 26 B 89 C 95 D 101

4 H2 Chemistry 9729/01 NYJC J2/2019 PRELIM 6 Use of the Data Booklet is relevant to this question. For the energy cycle given below, which enthalpy change is correctly stated? Ca(s) + C(s) + 3 2 O2(g) ∆H1 CaCO3(aq) ∆H2 ∆H3 ∆H4 Ca(g) + C(g) + 3O(g) ∆H8 ∆H5 ∆H6 ∆H7 Ca2+(g) + CO32–(g) CaCO3(s) All values are given in kJ mol–1. 1 ∆H7 = ∆H8 – ∆Hhyd (Ca2+) – ∆Hhyd (CO32–) 2 ∆H5 = 1740 3 ∆Hatm (Ca) = ∆H1 + ∆H8 – (∆H3 + ∆H4 + ∆H5 + ∆H6 + ∆H7) A 1, 2 and 3 B 1 and 2 only C 2 and 3 only D 3 only

5 H2 Chemistry 9729/01 NYJC J2/2019 PRELIM [Turn Over 7 The set-up shown is used to determine the enthalpy change of reaction for the neutralisation of oxalic acid, H2C2O4, using a calibration method. 2NaOH(aq) + H2C2O4(aq) → Na2C2O4(aq) + 2H2O(l) Using the results from experiments 1 and 2, and g iven standard enthalpy change of neutralisation is –57.4 kJ mol –1, what is the correct magnitude for the experimental value of ∆Hrxn in kJ mol–1? A 57.4 x 8.5 x 2 10 B 57.4 x 8.5 10 x 2 C 57.4 x 8.5 10 D 57.4 x 10 x 2 8.5 8 For which of the following processes is the sign of ∆GƟ and ∆SƟ different? 1 Addition of silicon chloride to water. 2 Bubbling chlorine gas into potassium iodide solution. 3 Thermal decomposition of magnesium carbonate. A 1, 2 and 3 B 1 and 2 only C 2 and 3 only D 1 only Experiment 1  50 cm3 of 2.0 mol dm-3 NaOH(aq) was added to 50 cm3 of 2.0 mol dm-3 HCl(aq).  Temperature of solution rise by 10.0 °C. Experiment 2  50 cm3 of 2.0 mol dm-3 NaOH(aq) was added to 50 cm3 of 2.0 mol dm-3 H2C2O4(aq).  Temperature of solution rise by 8.5 °C. ∆Hrxn

6 H2 Chemistry 9729/01 NYJC J2/2019 PRELIM 9 Nitrosyl chloride , NOCl, is a yellow gas produced by the reaction of colourless nitrogen monoxide gas and chlorine gas. 2NO + Cl2 → 2NOCl To investigate the kinetics of the production of nitrosyl chloride, experiments were carried out and the following graphs obtained. Which of the following can be deduced from these results? 1 The reaction is first order with respect to Cl2. 2 A possible mechanism for the reaction is: NO + Cl2 NOCl2 NOCl2 + NO 2NOCl 3 The rate constant has units of mol2 dm–6 min–1. A 1, 2 and 3 B 1 and 2 only C 2 and 3 only D 1 only 10 The decomposition of hydrogen peroxide in aqueous solution is a first order process. If 10 % of the hydrogen peroxide in a solution of concentration 0.10 mol dm-3 decomposes in 5 minutes at a certain temperature, what is the concentration, in mol dm-3, of a 1.00 mol dm-3 hydrogen peroxide solution after 5 minutes at the same temperature? A 0.10 B 0.50 C 0.80 D 0.90 Colour intensity of gas mixture time / min [NO]2 / mol2 dm–6 rate / mol dm–3 min–1 excess Cl2 excess NO max initial t 2t ¾ (max – initial) ½ (max – initial)

7 H2 Chemistry 9729/01 NYJC J2/2019 PRELIM [Turn Over 11 The pH of human blood is constant at about 7.40. Which ion present in the human body will remove contaminating H+(aq) ions from the blood to keep the pH constant? A CO32– B HCO3– C H2PO4– D PO43– 12 Values of three solubility products are given. Ksp (AgIO3) = 3.2 x 10–8 mol2 dm-6 Ksp (Ag2CrO4) = 9.0 x 10–12 mol3 dm-9 Ksp (Ag3AsO4) = 1.0 x 10–22 mol4 dm-12 A conical flask contains 0.10 mol dm -3 potassium iodate(V), 0.10 mol dm -3 potassium chromate(VI) and 0.10 mol dm-3 potassium arsenate(V), all in solution together. Drops of aqueous silver nitrate were added incrementally until the first precipitate appears. What is the concentration of silver ions, in mol dm-3, present? A 9.5 x 10–6 B 3.2 x 10–7 C 1.0 x 10–7 D 3.3 x 10–8

8 H2 Chemistry 9729/01 NYJC J2/2019 PRELIM 13 Use of the Data Booklet is relevant to this question. Free energy change of a reduction half-equation is related to the standard electrode potential by the equation. ∆GƟ = −nFEƟ The free energy, −∆GƟ/F, for the reduction of uranium species are given in the table. half-equation −∆GƟ/F (V) UO22+ + e– UO2+ +0.16