2024 JPJC Prelim P2 answers

© Jurong Pioneer Junior College [Turn Over NAME CLASS 23S JURONG PIONEER JUNIOR COLLEGE JC2 PRELIMINARY EXAMINATION 2024 CHEMISTRY 9729/02 Paper 2 Structured Questions 10 September 2024 2 hours Candidates answer on the Question Paper. Additional Materials: Data Booklet READ THESE INSTRUCTIONS FIRST Write your name, class and index number in the spaces at the top of this page. 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. 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 1 7 2 11 3 13 4 14 5 12 6 18 Penalty (delete accordingly) Lack 3sf in final answer –1 / NA Missing/wrong units in final ans –1 / NA Bond linkages –1 / NA Total 75 This document consists of 19 printed pages and 1 blank page.

2 © Jurong Pioneer Junior College 9729/02/J2 PRELIMINARY EXAM/2024 Answer ALL the questions in the spaces provided. 1 Use of the Data Booklet is relevant to this question. The most recent updates to the Periodic Table occurred in 2016, when IUPAC officially recognised the discovery of four new elements: Nihonium (Nh), Moscovium (Mc), Tennessine (Ts), and Oganesson (Og), completing the seventh row of the table. Table 1.1 lists the number of protons, neutrons and electrons in four particles, each from one of the elements mentioned above. Each particle may be an atom, an anion or a cation. Table 1.1 element particle atomic no. nucleon no. no. of protons no. of neutrons no. of electrons Nihonium (Nh) Nh 113 286 113 173 113 Moscovium (Mc) Mc3− 115 290 175 118 Tennessine (Ts) Ts− 117 177 Oganesson (Og) Og 294 118 118 For Examiner’s Use (a) Based on the positions of the four new elements in the Periodic Table, state the Group that each of the elements belong to. Nh …………………… Mc …………………… Ts …………………… Og …………………… Nh: Group 13 Mc: Group 15 Ts: Group 17 Og: Group 18 All groups correct. Do not accept Group 3, 5, 7, 0. [1] [1]

3 © Jurong Pioneer Junior College 9729/02/J2 PRELIMINARY EXAM/2024 [Turn Over Examiner’s comments: Students would need to recall that elements in the periodic table are arranged according to their atomic number / proton number. By referring to the Data Booklet, it is clear that the 4 missing elements belong to Group 13, 15, 17 and 18 respectively. Common mistakes that are not accepted: - Group 3, 5, 7, 8, 0 - Group III, V, VII, VIII, VIII (b) Fill in the empty spaces in Table 1.1. element parti -cle atomic no. nucleon no. no. of protons no. of ne