TMJC 2025 H1 Chem P1 QP

___________________________________________________________________ H1 CHEMISTRY 8873/01 Paper 1 Multiple Choice 25 September 2025 1 hour Additional materials: Multiple Choice Answer Sheet Data Booklet _________________________________________________________________________ READ THESE INSTRUCTIONS FIRST Write in soft pencil. There are thirty questions in this section. Answer all questions. For each question, there are four possible answers labelled A, B, C and D. Choose the one you consider correct and record your choice in soft pencil on the separate Answer Sheet. Read very carefully the instructions on the use of Answer Sheet. You are advised to fill in the Answer Sheet as you go along; no additional time will be given for the transfer of answers once the examination has ended. 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 12 printed pages. Use of Answer Sheet Ensure you have written your name, class, date and subject on the Answer Sheet. Shade the last four digits of your centre/index number on the Multiple Choice Answer Sheet. (e.g. if your centre/index number is 30541234, shade 1234). Use a 2B pencil to shade your answers on the Answer Sheet; erase any mistakes cleanly. Multiple shaded answers to a question will not be accepted. TAMPINES MERIDIAN JUNIOR COLLEGE JC2 PRELIMINARY EXAMINATION

2 Tampines Meridian Junior College 2025 JC2 Preliminary Examination H1 Chemistry [Turn over 2 Atoms of elements from hydrogen to zinc have specific electronic arrangements. Which statement is correct? A The shell with principal quantum number 3 can hold a maximum of 8 electrons. B The electrons always occupy the highest energy orbitals available. C The order of filling the orbitals is 1s, 2s, 2p, 3s, 3p, 3d, 4s. D In some atoms, electrons occupy the fourth shell even though the third shell is not full. 4 Which combination correctly represents the shape around the central atom in each of the species? SH2 BF3 NCl3 A linear trigonal pyramidal trigonal planar B linear trigonal planar trigonal pyramidal C bent trigonal pyramidal trigonal planar D bent trigonal planar trigonal pyramidal 1 The relative atomic mass of antimony, which consist of the isotopes 121Sb and 123Sb, is 121.8. Calculate the percentage of 123Sb in the isotopic mixture. A 40% B 45% C 50% D 60% 3 Elements E and F have the following successive ionisation energies in kJ mol−1. 1st 2nd 3rd 4th 5th 6th 7th E 580 1800 2700 11600 14800 18400 23300 F 1310 3400 5300 7500 11000 13300 20300 What could be the formula of the compound formed by these two elements? A EF3 B E2F3 C E3F2 D E4F3

3 Tampines Meridian Junior College 2025 JC2 Preliminary Examination H1 Chemistry [Turn over 5 Gases can be liquefied under certain conditions. Which statements about liquefaction of a non-polar gas are correct? 1 Some gases can be liquefied at room temperature by applying pressure. 2 The strength of the intermolecular forces is negligible at high pressure. 3 The strength of the intermolecular forces becomes more significant at low temperature. A 1 and 2 only B 1 and 3 only C 2 and 3 only D 1, 2 and 3 6 Ammonium lauryl sulfate (ALS) is an anionic surfactant found primarily in shampoos and body–wash as a foaming agent. ALS is soluble in both water and oil. The structure of ALS is as follows. Which statement is incorrect about ALS? A It is soluble in oil, due to the presence of compatible intermolecular instantaneous dipole–induced dipole interactions with oil molecules. B It is soluble in water, due to the presence of ion –dipole interactions with water molecules. C It has a high melting and boiling point due to the hydrogen bonding between the particles. D The pi bond in S=O is due to the side-on overlap of the orbitals. 7 Consecutive elements L, M and N are in Period 3 of the Periodic Table. Element M has the lowest melting point and the highest first ionisation energy of these three elements. What are the identities of L, M and N? A sodium, magnesium, aluminium B magnesium, aluminium, silicon C aluminium, silicon, phosphorus D silicon, phosphorus, sulfur

4 Tampines Meridian Junior College 2025 JC2 Preliminary Examination H1 Chemistry [Turn over 8 Which statement about Period 3 elements is true across the period? A The pH of the oxides in water decreases. B The solubility of the oxides in water increases. C The melting points of the elements decreases. D The electrical conductivity of the elements decreases. 9 How do the following properties for Group 1 elements change down the group? reducing power ionic radius ionisation energy A increases increases decreases B increases decreases increases C decreases decreases increases D decreases increases decreases 10 Which statements are correct for all three halogens, chlorine, bromine and iodine? 1 The volatility decreases down the group. 2 The electronegativity increases down the group. 3 Their reactivity as oxidising agents decreases down the group. 4 They form hydrides that are strong acids in aqueous solutions. A 1 and 2 only B 1 and 3 only C 3 and 4 only D 1, 3 and 4 only 11 Oxygen-17, 17O, isotope is commonly used in Nuclear Magnetic Resonance Spectroscopy to study the chemical environment of oxygen atoms in molecules. How many neutrons are present in 0.17 g of 17O? [L = Avogadro constant] A 0.01L B 0.08L C 0.09L D 0.17L

5 Tampines Meridian Junior College 2025 JC2 Preliminary Examination H1 Chemistry [Turn over 12 Use of the Data Booklet is relevant to this question. Titanite is a mineral known to be a relatively soft gemstone. A particular sample of titanite has the following composition by mass: Ca: 20.5% Ti: 24.4% Si: 14.3% O: 40.8% The empirical formula of titanite is CawTixSiyOz. What is the value of z? A 2 B 3 C 5 D 7 13 25.0 cm 3 of an aqueous solution of 0 .200 mol dm −3 T2+ required 20.00 cm 3 of 0.100 mol dm−3 of acidified KMnO4(aq) for a complete reaction. What is the final oxidation state of T? A 0 B +3 C +4 D +5 14 Under acidic conditions, bromate(V) ions and bromide ions react as shown. BrO3 – + 5Br – + 6H+ → 3Br2 + 3H2O The reaction is found to be first order with respect to both BrO3 – and Br – and second order with respect to H+. The initial concentration of BrO3 – and Br – is increased by a factor of 4 while concentration of H+ decreased by half. By which factor will the initial rate increase? A 2 B 4 C 8 D 16 15 Caffeine is a drug that increases the activity of the brain and nervous system. Its elimination from the body follows a first-order kinetics with a half-life of 5.0 h. How long will it take for someone who took 52 mg of caffeine, to have 6.5 mg of caffeine left in his system? A 6.5 h B 15.0 h C 20.0 h D 40.0 h

6 Tampines Meridian Junior College 2025 JC2 Preliminary Examination H1 Chemistry [Turn over 16 The Michaelis-Menten graph shows how the initial rate of reaction varies for an enzyme catalysed reaction as the concentration of the substrate changes. Which statement explains the shape of the graph? A The enzyme is acting as a limiting reagent and is being used up in the reaction. B Substrate molecules inhibit the enzyme at high concentrations which resulted in a constant rate. C At high substrate concentration, the order of reaction with respect to substrate is 1. D The reaction will reach a constan