2023 VJC H2 Chem Prelim P4 Ans

This document consists of 18 printed pages and 2 blank pages. © VJC 2023 9729/04/PRELIM/23 [Turn over CANDIDATE NAME CT GROUP VICTORIA JUNIOR COLLEGE PRELIMINARY EXAMINATION Higher 2 ……………………………………………….………….. …………………………….. CHEMISTRY 9729/04 Paper 4 Practical Candidates answer on the Question Paper. 24 Aug 2023 2 hours 30 minutes Additional Materials: As listed in the instructions below READ THESE INSTRUCTIONS FIRST Write your name and CT group 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. 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. Shift Laboratory For Examiner’s Use 1 2 3 4 Total / 55

2 © VJC 2023 9729/04/PRELIM/23 Answer all the questions in the spaces provided. 1 Inorganic and organic qualitative analysis In this question, you will carry out tests on two solutions, FA 1 and FA 3 , and make conclusions about them. Unless otherwise stated, the volumes given below are approximate and should be estimated rather than measured. Test and identity any gases evolved. If there is no observable change, write no observable change. (a) (i) FA 1 is an aqueous solution that contains two cations and one anion listed in the Qualitative Analysis notes. You will carry out the tests in Table 1.1, which will allow you to identify the two cations present in FA 1. Table 1.1 tests observations 1 Test the FA 1 solution using Universal Indicator paper. Using the colour chart provided, record the pH of the solution. • pH is about 2 or 3 (Universal indicator paper turns red OR orange) 2 To 1 cm depth of FA 1 , add 1 cm depth of KI. Let the solution stand for 1 min and observe any colour change that occurs. To the resulting solution, add 5 drops of starch solution. • Solution turns brown (OR darker) after 1 minute. • Solution turns blue-black (OR blue) with starch 3 To 2 cm depth of FA 1, add aqueous ammonia dropwise with shaking till 4 cm depth of aqueous ammonia has been added. Swirl and filter the mixture, collecting the filtrate in a clean test -tube. The filtrate is FA 2 which should be put to one s