MI Prelim H2 Chem P3 QP_for exchange

Class Adm No Candidate Name: This question paper consists of 22 printed pages. 2025 Preliminary Examination Pre-University 3 H2 CHEMISTRY 9729/03 Paper 3 Free Response 15 Sep 2025 2 hours Candidates answer on the Question Paper Additional materials: Data Booklet READ THESE INSTRUCTIONS FIRST Do not turn over this question paper until you are told to do so Write your name, class and admission number on all the work you hand in. 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. If additional space is required, you should use the page at the end of this booklet. The question number must be clearly shown. Section A Answer all questions. Section B Answer one question. A Data Booklet is provided. The use of an approved scientific calculator is expected, where appropriate. The number of marks is given in brackets [ ] at the end of each question or part question. Question A B Total 1 2 3 4 / 5 Marks 21 16 23 20 80 H

2 Section A Answer all the questions in this section. 1 Copper and iron are transition metals that form a wide array of complexes due to their ability to exhibit multiple oxidation states. Copper and iron complexes showcase diverse chemical and biological roles, ranging from catalysis to electrochemical processes. (a) (i) State two physical properties of transition metals which differ from that of main group elements. [2] (ii) When copper(I) oxide solid, Cu2O was added to sulfuric acid, H2SO4(aq), and warmed, a blue solution and a pink solid were observed. Identify the blue solution and the pink solid and write a balanced chemical equation for the reaction. [2] (iii) Ethylenediaminetetraacetic acid (EDTA) is a compound used in chelation therapy. Suggest why [Cu(EDTA)]2− and [Cu(NH3)4(H2O)2]2+ complexes have different colours. [1] ………………………………………………………………………………………………………………... ………………………………………………………………………………………………………………... ………………………………………………………………………………………………………………... ………………………………………………………………………………………………………………... ………………………………………………………………………………………………………………... ………………………………………………………………………………………………………………... ………………………………………………………………………………………………………………... ………………………………………………………………………………………………………………... ………………………………………………………………………………………………………………... ………………………………………………………………………………………………………………... ………………………………………………………………………………………………………………... ………………………………………………………………………………………………………………... ………………………………………………………………………………………………………………... ………………………………………………………………………………………………………………... ………………………………………………………………………………………………………………... ………………………………………………………………………………………………………………..