VJC JC2 H1 Prelim P1 QP with Ans

1 © VJC 2025 8873/01/PRELIM/25 [Turn over VICTORIA JUNIOR COLLEGE JC 2 PRELIMINARY EXAMINATION Higher 1 CHEMISTRY ANSWER 8873/01 Paper 1 Multiple Choice 19 September 2025 1 hour Additional Materials: Multiple Choice Answer Sheet Data Booklet READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, glue or correction fluid. Write your name and CT group on the Answer Sheet. There are thirty questions on this paper. Answer all questions. For each question there are four possible answers A, B, C and D. Choose the one you consider correct and record your choice in soft pencil on the separate Answer Sheet. A Data Booklet is provided. Read the instructions on the Answer Sheet very carefully. Each correct answer will score one mark. A mark will not be deducted for a wrong answer. Any rough working should be done in this booklet. The use of an approved scientific calculator is expected, where appropriate. This document consists of 10 printed pages.

2 © VJC 2025 8873/01/PRELIM/25 For each question there are four possible answers, A, B, C, and D. Choose the one you consider to be correct. 1 9Be is used in the production of ‘fast neutrons’. How many neutrons are present in 0.09 g of 9Be? [L = Avogadro constant] A 0.04 L B 0.05 L C 0.09 L D 0.45 L Answer: B Amount of 9Be = 0.09 / 9 = 0.01 mol No. of 9Be atoms = 0.01 x L = 0.01 L Mole ratio of 9Be : neutrons 1 : (9–4) = 5 No. of neutrons = 0.01 L x 5 = 0.05 L 2 The table below shows the fifth, sixth, seventh, eighth and ninth ionisation energies of elements L and M in kJ mol–1. Elements L and M are found in period 3. 5th 6th 7th 8th 9th L 6270 21300 25400 29900 35900 M 6540 9360 11000 33600 38600 Given that all the atoms have at least an octet configuration, what could not be the formula of the compound formed by these two elements? A LM5 B LM4+ C LM3 D LM2 Answer: D For element L, there is a large increase from the 5th to the 6th ionisation energy, indicating that the 6th electron is removed from the next inner quantum shell. This means that the element has 5 valence electrons and is in group 15. The element is Phosphorous. For element M, there is a large increase from the 7th to the 8th ionisation energy, indicating that the 8th electron is removed from the next inner quantum shell. This means that the element has 7 valence electrons and is in group 17. The element is Chlorine. Since elements L and M are in the same period and element L has less valence electrons, element L is less electronegative than element M as electronegativity increases across the period. Hence, element L should be the central atom in th