2024 Prelims TJC H2 Chem P2 (QP)

9729 / TJC Prelims / 2024 DO NOT WRITE IN THIS MARGIN [Turn over TEMASEK JUNIOR COLLEGE 2024 JC2 PRELIMINARY EXAMINATION Higher 2 CANDIDATE NAME CLASS CENTRE NUMBER S INDEX NUMBER Chemistry 9729/02 Paper 2 Structured Questions 21 August 2024 2 hours Candidates answer on the Question Paper. Additional Materials: Data Booklet READ THESE INSTRUCTIONS FIRST Write your Centre number, index number, name and class 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. The use of an approved scientific calculator is expected, where appropriate. The number of marks is given in bracket [ ] at the end of each question or part question. This document consists of 21 printed pages and 3 blank pages. For Examiner’s Use Paper 1 /30 Paper 2 Q1 / 14 Q2 / 15 Q3 / 16 Q4 / 20 Q5 / 10 Total /75 Paper 3 /80 TOTAL (%) /100

2 DO NOT WRITE IN THIS MARGIN 9729 / TJC Prelims / 2024 DO NOT WRITE IN THIS MARGIN DO NOT WRITE IN THIS MARGIN DO NOT WRITE IN THIS MARGIN Answer all questions in the spaces provided. 1 (a) Table 1.1 shows the successive ionisation energies of an element A. Table 1.1 ionisation energies / kJ mol−1 1st 2nd 3rd 4th 5th 6th 7th 8th 9th 10th element A 945 1794 2735 4839 6056 11690 14180 17370 20550 23830 (i) Explain why the successive ionisation energies of an element always increase. [1] (ii) Element A is in Period 4. Using information from Table 1.1 and the Data Booklet, identify element A. Explain your answer clearly. [2] (iii) State and explain how the first ionisation energy of element A will compare to that of the element to its right in the Periodic Table. [2]

3 DO NOT WRITE IN THIS MARGIN DO NOT WRITE IN THIS MARGIN DO NOT WRITE IN THIS MARGIN 9729 / TJC Prelims / 2024 DO NOT WRITE IN THIS MARGIN [Turn over (b) (i) With the aid of a labelled diagram. describe the structure and bonding of barium. [2] (ii) Explain the trend in atomic radii down Group 2. [2] (iii) The density of magnesium and barium is 1.7 g cm–3 and 3.6 g cm–3 respectively. Explain why the density of barium is significantly greater than that of magnesium. [1]

4 DO NOT WRITE IN THIS MARGIN 9729 / TJC Prelims / 2024 DO NOT WRITE IN THIS MARGIN DO NOT WRITE IN THIS MARGIN DO NOT WRITE IN THIS MARGIN (iv) When magnesium is burned in air, a mixture of the ionic solids magnesium oxide and magnesium nitride, Mg3N2, is formed. Adding water to Mg3N2 produces an alkaline gas and a white insoluble solid. Suggest an equation for the reaction b