HCI 2024 Prelim P4 QP

This document consists of 16 printed pages. HWA CHONG INSTITUTION C2 Preliminary Examination Higher 2 CANDIDATE NAME CT GROUP 2 3 S CENTRE NUMBER S INDEX NUMBER CHEMISTRY Paper 4 Practical 9729/04 20 August 2024 2 hours 30 minutes Candidates answer on the Question Paper. READ THESE INSTRUCTIONS FIRST Write your name, CT group, centre number 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. DO NOT WRITE ON ANY BARCODES. 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. Qualitative Analysis Notes are printed on pages 15 and 16. 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 Shift Laboratory For Examiner’s Use 1 2 3 4 Total

2 © Hwa Chong Institution 2024 9729/04/C2 Preliminary Examination Answer all questions in the spaces provided. 1 Qualitative Analysis of FA 1 FA 1 is an aqueous solution containing two cations & one anion. FA 2 is hydrogen peroxide. You will perform tests to identify the cations and anion in FA 1. Unless otherwise stated, the volumes given are approximate and should be estimated rather than measured. At each stage of any test, you are to record details of the following. • colour changes seen • the formation of any precipitate • the solubility of such precipitates in an excess of the reagent added Where gases are released, they should be identified by a test, described in the appropriate place in your observations. You should indicate clearly at what stage in a test a change occurs. No additional tests for ions present should be attempted. (a) (i) Carry out the following tests. Carefully record your observations in Table 1.1. Table 1.1 Note: Observations to test 1 have been recorded for you. MMO M test observations 1 To 1 cm depth of FA 1 in a test-tube, add one spatula full of solid sodium carbonate. Effervescence of colourless and odourless gas that gives white ppt in limewater. White ppt observed after effervescence ceased. 2 Place 1 cm depth of FA 1 in a boiling tube using a dropping pipette. Measure 6 cm3 of aqueous sodium hydroxide with a measuring cylinder. Transfer 1 cm3 of aqueous sodium hydroxide to FA 1 in the boiling tube using a dropping pipette. Mix the contents of the tube thoroughly. Repeat this with another 1 cm3 of aqueous sodium hydroxide. Repeat until the measuring cyli