2025 YIJC H1 Chem Prelim P2 Solutions (for exchange)

©YIJC [Turn over YISHUN INNOVA JUNIOR COLLEGE JC 2 PRELIMINARY EXAMINATION Higher 1 CANDIDATE NAME TEACHER’S COPY CG H1 GROUP 1 / 2 CHEMISTRY Paper 2 Structured and Free Response Questions Candidates answer on the Question Paper. Additional Materials: Data Booklet 8873/02 XX September 2025 2 hours READ THESE INSTRUCTIONS FIRST This document consists of 16 printed pages and 1 blank page. For Examiner’s Use Section A 1 / 11 2 / 9 3 / 11 4 / 12 5 / 5 6 / 12 Section B 7 or 8 / 20 Penalty units significant figures Total / 80 Write your name and class in the spaces 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. Section B Answer one question. The use of an approved scientific calculator is expected, where appropriate. The number of marks is given in brackets [ ] at the end of each question or part question.

©YIJC [Turn over 2 Section A Answer all the questions in this section in the spaces provided. 1 (a) Elements A, B and C are three consecutive elements from Period 3 of the Periodic Table. Element B has the successive ionisation energies as shown in Table 1.1. Table 1.1 ionisation energies / kJ mol–1 1st 2nd 3rd 4th 5th 6th 7th 8th 577 1820 2740 11600 14800 18400 23300 27400 (i) Explain how the data shows that element B belongs to Group 13. ………………………………………………………………………………………………………. ………………………………………………………………………………………………………. …………………………………………………………………………………………………….[1] Largest jump in ionization energy from removing 3rd electron to removing 4th electron. 4th electron is located in an inner principal quantum shell. There are 3 valence electrons. (ii) Hence, write the full electronic configuration of B. 1s2………………………………………………………………………………………………...[1] 2s2 2p6 3s2 3p1 (iii) Explain why the first ionisation energy of element B is lower than the first ionisation energy of elements A and C. ………………………………………………………………………………………………………. ………………………………………………………………………………………………………. ………………………………………………………………………………………………………. ………………………………………………………………………………………………………. ………………………………………………………………………………………………………. ………………………………………………………………………………………………………. ………………………………………………………………………………………………………. …………………………………………………………………………………………………….[3]

©YIJC [Turn over 3 Element B (Group 13) and A (Group 2): The outermost electron in A is in t