2024 Prelims ACJC H2 Chem P2 (QP)

This paper consists of 22 printed pages and 2 blank pages. Anglo-Chinese Junior College JC2 Preliminary Examination Higher 2 CANDIDATE NAME FORM CLASS TUTORIAL CLASS INDEX NUMBER CHEMISTRY Paper 2 Structured Questions Candidates answer on the Question Paper. Additional materials: Data Booklet 9729/02 21 August 2024 2 hours READ THESE INSTRUCTIONS FIRST Write your form class, index number and name 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. Answer all questions in the spaces provided on the Question Paper. The use of an approved scientific calculator is expected, where appropriate. A Data Booklet is provided. The number of marks is given in brackets [ ] at the end of each question or part question. For Examiner's Use Question no. Marks 1 / 12 2 / 11 3 / 10 4 / 10 5 / 10 6 / 22 Presentation of answers TOTAL / 75

2 © ACJC2024 9729/Preliminary Examination/2024 [Turn over Section B: Structured Questions (75 marks) Answer all the questions in the spaces provided. 1 Y and Z are two elements found in Period 3. Their fifth to eighth ionisation energies are given in Table 1.1. Table 1.1 successive ionisation energies / kJ mol–1 5th 6th 7th 8th Y 6530 9353 11019 33606 Z 7004 8496 27107 31719 (a) (i) State and explain the group number of Y. ..………………………………………………………………………………..…………. ..………………………………………………………………………………..…………. ..………………………………………………………………………………..…………. ………………………………………………………………………………..………..[1] (ii) Complete the electronic configurations of Y+ and Z+. Y+ 1s2…………………………………………………………………..…………........... Z+ 1s2………………………………………………………………………..………....[1] (iii) From your answer in (a)(ii), explain why the second ionisation energy of Y is expected to be lower than Z. ………………………………………………………………………………..……….….. ..………………………………………………………………………………..…………. ………………………………………………………………………………..……..…[1] (iv) However, it turns out that the second ionisation energies of Y and Z are 2300 kJ mol–1 and 2260 kJ mol–1 respectively. Suggest why Y has a higher second ionisation energy than Z. ..………………………………………………………………………………..…………. ………………………………………………………………………………..……..…[1]

3 © ACJC2024 9729/Preliminary Examination/2024 [Turn over (b) (i) The atomic radii of some Period 4 elements are shown in Fig. 1.1. Fig. 1.1 With reference to Fig. 1.1, describe and explain the shape of the graph from • V to Zn • Ga to Br ..………………………………………………………………………………..…………. ..………………………………………………………………………………..…………. ..………………………………………………………………………………..…………. ..………………………………………………………………………………..…………. ..………………………………………………………………………………..……