TMJC_2025_H2 Chem_P4_Answer

CANDIDATE NAME Answers CIVICS GROUP H2 CHEMISTRY 9729/04 Paper 4 Practical 3 September 2025 2 hours 30 minutes Candidates answer on the Question Paper. This document consists of 19 printed pages and 3 blank pages. READ THESE INSTRUCTIONS FIRST Write your name and Civics Group in the spaces at the top of the page. Give details of the practical shift and laboratory where appropriate, in the boxes provided. Write in dark blue or black pen. You may use an 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 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 21 and 22. The number of marks is given in brackets [ ] at the end of each question or part question. Shift Laboratory For Examiner’s Use 1 / 10 2 / 19 3 / 17 4 / 9 Total / 55 TAMPINES MERIDIAN JUNIOR COLLEGE JC2 PRELIMINARY EXAMINATION

2 Tampines Meridian Junior College 2025 JC2 Preliminary Examinations H2 Chemistry Answer all questions in the spaces provided. 1 Qualitative analysis tests involving solid iron(III) chloride FA 1 is a solution containing iron(III) chloride, FeCl3.nH2O FA 2 is a solution containing an unknown L– ligand Carry out the following tests. Record your observations in Table 1.1. Unless otherwise stated , the volumes given in Table 1.1 are approximate and should be estimated rather than measured. Test and identify any gases evolved. If there is no observable change, write no observable change. Table 1.1 Test Observations Explanation (teacher’s notes) (a) (i) Add about 6 cm depth of FA1 into a test tube. Add aqueous silver nitrate in excess. Filter the mixture. Separate the filtrate into four test tubes for (iii), (iv), (v) and (vi). white ppt formed in yellow/orange solution White residue/ppt obtained Yellow/orange filtrate/solution obtained Cl– is present to form AgCl ppt [Fe(H2O)6]3+ complex is present (ii) Place the filter funnel containing the residue on a new test tube, add aqueous ammonia over the residue and collect the filtrate. To this filtrate, add nitric acid dropwise until no further changes. The white ppt was soluble/dissolves in aqueous ammonia to form a colourless/pale yellow/orange solution. With nitric acid, white ppt formed. White ppt remains insoluble in excess nitric acid. Cl– is present. [Ag(NH3)2]+ is formed. It should be a colourless solution but the ppt is covered with traces of Fe3+, hence the solution appears pale yellow. Reversal of equilibrium. HNO3 neutralise the NH3 and hence AgCl is formed again. (iii) To the first