Copy of 2024 CCHM Chemistry 6092 P2

[Turn over Name: Class: Class Register Number: PRELIMINARY EXAMINATION 2024 SECONDARY 4 CHEMISTRY 6092/02 Paper 2 21 August 2024 1 hour 45 minutes Candidates answer on the Question Paper. No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your name, class and register number clearly in the spaces provided at the top of this page. 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. Section A Answer all questions in the spaces provided. Section B Answer one question. Write your answers in the spaces provided. The number of marks is given in brackets [ ] at the end of each question or part question. A copy of the Periodic Table is printed on page 24. The use of an approved scientific calculator is expected, where appropriate. For Examiner’s Use Section A / 70 Section B / 10 Total / 80 This document consists of 23 printed pages and 1 blank page.

2 2024 Preliminary Exam/CCHMS/Secondary 4/Chemistry/6092/02 Section A Answer all questions. 1 The electronic structures of five atoms, A, B, C, D and E, are shown. A B C D E (a) Answer the following questions about these electronic structures. Each electronic structure may be used once, more than once or not at all. State which electronic structure, A, B, C, D or E represents: (i) an atom of an element in Group 2 of the Periodic Table ………………………...…………………………………………………………,……..[1] (ii) an atom of a very reactive metal …………………………………………………...…………………………………,…..[1] (iii) an atom with a proton number of 17 …………………………………………………...………………………………,……..[1] (iv) an atom that forms a stable ion with a charge of 2− ……………………………………………………...……………………………,……..[1] (b) Atoms B and C reacts to form a compound. Draw a ‘dot -and-cross’ diagram to show the bonding between atoms B and C. Show outer electrons only. [2] [Total: 6]

3 [Turn over 2024 Preliminary Exam/CCHMS/Secondary 4/Chemistry/6092/02 2 Silver dichromate, Ag2Cr2O7, is a red insoluble salt. Silver dichromate can be made by reacting silver nitrate solution with ammonium dichromate solution as shown by the equation below. 2AgNO3 + (NH4)2Cr2O7 → 2NH4NO3 + Ag2Cr2O7 (a) (i) Describe how you can obtain pure and dry solid silver dichromate after mixing silver nitrate solution and ammonium dichromate solution. ……………………………………………………………………………………………... ……………………………………………………………………………..…….……..[2] (ii) Describe the steps that you would take to determine if silver nitrate solution is present in the reaction mixture after the reaction stops. ………………………………………………………………………………………..….... ………………………………………………………………………………………..….... …………………………………………………………………………………………...... …………………………………………………………………