ASRJC 2022 J2 H2Prelim P4 QP

ASRJC JC2 PRELIM 2022 9729/04/H2 [Turn Over ANDERSON SERANGOON JUNIOR COLLEGE 2022 JC 2 PRELIMINARY EXAMINATION NAME:________________________________ ( ) CLASS: 22 /____ CHEMISTRY 9729/04 Paper 4 Practical 25 August 2022 2 hours 30 minutes Candidates answer on the Question Paper. Additional Materials: As listed in the Confidential Instructions READ THESE INSTRUCTIONS FIRST Write your name, class and index number on all the work you hand in. Give details of the practical shift and laboratory where appropriate, in the boxes provided. Write in dark blue or black pen. You may use a HB pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. Answer all questions in the spaces provided on the Question Paper. The use of an approved scientific calculator is expected, where appropriate. You may lose marks if you do not show your working or if you do not use appropriate units. Quantitative Analysis Notes are printed on pages 23 and 24. Shift Laboratory At the end of the examination, fasten all your work securely together. The number of marks is given in brackets [ ] at the end of each question or part question. For Examiner’s Use 1 / 14 2 / 21 3 / 9 4 / 11 Total / 55 This document consists of 22 printed pages and 2 blank pages.

2 ASRJC JC2 PRELIM 2022 9729/04/H2 Answer all the questions in the spaces provided. 1 Determination of a value for an enthalpy change of solution by an indirect method FA 1 is solid sodium hydrogencarbonate, NaHCO3. FA 2 is 1.50 mol dm–3 sulfuric acid, H2SO4. Sodium hydrogencarbonate dissolves in water according to equation 1. equation 1 NaHCO3(s) + aq → Na+(aq) + HCO3–(aq) H1 Both solid and aqueous sodium hydrogencarbonate react with sulfuric acid. equation 2 2NaHCO3(s) + H2SO4(aq) → Na2SO4(aq) + 2H2O(l) + 2CO2(g) H2 equation 3 2NaHCO3(aq) + H2SO4(aq) → Na2SO4(aq) + 2H2O(l) + 2CO2(g) H3 In this question, you will perform an experiment to determine a value for H2. You will use data provided to calculate H3 and hence a value for H1. (a) Determination of the molar enthalpy change of reaction, H2 In this experiment, you will determine the maximum temperature change when a known mass of solid sodium hydrogencarbonate, FA 1, reacts with dilute sulfuric acid, FA 2. In an appropriate format in the space provided on page 3 , prepare tables in which to record for your experiment: • all weighings to an appropriate level of precision, • all values of temperature, T, to an appropriate level of precision. Procedure 1. Weigh the capped bottle containing FA 1. Record this mass. 2. Place one polystyrene cup inside another polystyrene cup and place both in a glass beaker. 3. Use a 25 cm3 measuring cylinder to transfer 25 cm 3 of FA 2 into the polystyrene cup. 4. Stir the FA 2 in the polystyrene cup with the thermometer. Read an