2025 RI H1Chem Prelims P2 Questions

RAFFLES INSTITUTION 2025 YEAR 6 PRELIMINARY EXAMINATION Higher 1 CANDIDATE NAME CLASS INDEX NUMBER CHEMISTRY 8873/02 Paper 2 Structured Questions 16 September 2025 2 hours Candidates answer on the Question Paper. Additional Materials: Data Booklet READ THESE INSTRUCTIONS FIRST Do not open this question booklet until you are told to do so. Write your name, class and index number in the spaces provided at the top of this page. Write in dark blue or black pen. You may use a n HB pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. Section A Answer all the questions. Section B Answer one question. The use of an approved scientific calculator is expected, where appropriate. A Data Booklet is provided. Do not write anything in it. You are reminded of the need for good English and clear presentation in your answers. The number of marks is given in brackets [ ] at the end of each question or part question. This document consists of 26 printed pages and 2 blank pages. For Examiner’s Use Section A 1 / 11 2 / 8 3 / 9 4 / 7 5 / 9 6 / 12 7 / 4 Section B (Please circle the question you have attempted) 8 / 20 9 / 20 Total / 80

2 © Raffles Institution 2025 8873/02/S/25 [Turn Over Section A Answer all the questions in this section in the spaces provided. 1 (a) Oxygen exists in various forms, including atoms, ions, and isotopes, each with distinct properties and applications. (i) Complete Table 1.1 for two species of oxygen. Table 1.1 species number of protons number of neutrons number of electrons electronic configuration 16 + 8O 8 1s2 16 2- 82O [2] (ii) Sketch an orbital in which the highest energy electron can be found in 16 + 8O . Label the orbital. [1]

3 © Raffles Institution 2025 8873/02/S/25 [Turn Over (b) The magnitude of angle of deflection for the path of a beam of O+ ions in an electric field is x. Add labelled lines to Fig. 1.1 to represent the paths of the beams of O+ and O22− ions in this electric field. + − Fig. 1.1 [1] Hence, state if the angle of deflection of O22− ions is greater, smaller or equal to x. …………………………………………………………………………………..………………[1] (c) The relative atomic mass of an element depends on the per