2025 Prelim 9729 P4_final MS_H2 Chem_CJC

[Turn over 9729/04/CJC JC2 Preliminary Examinations 2025 CANDIDATE NAME CLASS 2T CHEMISTRY 9729/04 Paper 4 Practical 26 August 2025 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 and class in the boxes above. 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 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 17 and 18. 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. This document consists of 18 printed pages. Instruction Catholic Junior College JC2 Preliminary Examinations Higher 2 Shift Laboratory For Examiner’s Use 1 / 13 2 / 11 3 / 19 4 / 12 Total / 55

2 9729/04/CJC JC2 Preliminary Examinations 2025 Answer all the questions in the spaces provided. 1 Investigation of an organic compound and an inorganic compound FA 1 is an aqueous solution that contains a mixture of salts with two cations and one anion listed in the Qualitative Analysis Notes. FA 2 is an aqueous solution of an organic compound, X, with only one functional group present. You will perform tests to identify: • the ions present in FA 1. • the functional group of X in FA 2. (a) (i) Carry out the following tests. Carefully record your observations in Tables 1.1 and 1.2. The volumes given below 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 tests observations 1 To 1 cm depth of FA 1 in a boiling tube, add aqueous sodium hydroxide until there is no further change. Heat the boiling tube gently. 2 To 1 cm depth of FA 1 in a test-tube, add a few drops of Ba(NO3)2 (aq). Then, add excess nitric acid. 3 To 1 cm depth of FA 1 in a test-tube, add excess aqueous hydrogen peroxide until no further change. From your observations, identify the ions present in FA 1. The cations are ......................... and ...................... . The anion is ..................................... . [7] Fe2+ NH4+. SO42 – Pale green solution turned brown/ orange- yellow. Effervescence observed. O2 gas relighted a glowing splint. White ppt formed, insoluble in excess HNO3. Green