2025 ASRJC Prelim H1Chem P1 QP

ASRJC JC2 Prelim 2025 8873/H1 [Turn over ANDERSON SERANGOON JUNIOR COLLEGE 2025 JC 2 PRELIMINARY EXAMINATION NAME:______________________________ ( ) CLASS: 25 / ___ CHEMISTRY 8873/01 Paper 1 Multiple Choice 2 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 class on the Answer Sheet in the spaces provided. 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. 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 14 printed pages and 2 blank pages. Multiple Choice Answer Sheet Write your name, class and NRIC / FIN number, including the reference letter. Shade the NRIC / FIN number. Exam Title: JC2 Preliminary Exam Exam Details: H1 Chemistry / Paper 1 Date: 02/09/2025

2 ASRJC JC2 Prelim 2025 8873/H1 1 Use of the Data Booklet is relevant to this question. L is the Avogadro constant. Which statement is correct? A 71.0 g of chlorine gas contains 2 L molecules. B 1.00 mol of sodium sulfate contains 3 L ions. C 6.9 g of lithium ion, Li+, contains 3 L electrons. D 48 dm3 of hydrogen gas, measured at r.t.p, contains 2 L atoms. 2 Use of the Data Booklet is relevant to this question. Iodine-131 is radioactive and is used in thyroid cancer treatment. Which statements about this element are correct? 1 There are p electrons present in 5 quantum shells. 2 There are 78 neutrons, 53 protons and 54 electrons in the negative ion of 131 53I . 3 All electrons in the negative ion of 131 53I are paired. A 1, 2 and 3 B 2 and 3 only C 1 and 3 only D 2 only

3 ASRJC JC2 Prelim 2025 8873/H1 [Turn Over 3 The first seven ionisation energies of an element Y are shown in the sketch graph. What could be the identity of element Y? A Bromine B Carbon C Phosphorus D Silicon

4 ASRJC JC2 Prelim 2025 8873/H1 4 A beam of particles contains He4 2+ and 𝑒−0 ions. All particles approach an electric field at the same speed. Which diagram indicates the deflection of these particles as they pass through the electric field? A B C D He4 2+ e−0 e−0 e−0 e−0 He4 2+ He4 2+ He4 2+

5 ASRJC JC2 Prelim 2025 8873/H1 [Turn Over 5 Use of the Data Booklet is relevant to this question. Under acidic conditions, potassium manganate(VII) reacts with potassium iodide. The iodine that was liberated can be determined by titrating with sodium thiosulfate solution. The relevant equations are shown but not balanced. Reaction I: 2 MnO4–(aq) +16 H+(aq) + a I–(aq) … Mn2+(aq) + … H2O(l) + … I2(aq) Reaction II: b I2(aq) + 2 S2O32−(aq) … I−(aq) + …S4O62−(aq) What are the values of a and b in the correctly balanced equations? a b A 10 1 B 10 2 C 5 1 D 5 2 6 Use of the Data Booklet is relevant to this question. The complete combustion of 0.0050 mol of hydrocarbon W requires 0.540 dm3 of oxygen measured at r.t.p. 0.27 g of water is produced. What is the molecular formula of W? A C2H6 B C3H6 C C3H8 D C4H8 7 Which equation shows a reaction in which co-ordinate (dative covalent) bonds are formed? A NO2 + NO2 N2O4 B 2NO + 2H2 N2 + 2H2O C H2O + H+ H3O+ D Cl2 + CH4 CH3Cl + HCl

6 ASRJC JC2 Prelim 2025 8873/H1 8 Sulfur dioxide is a very important compound in winemaking. Sulfur dioxide can be represented as O S O . Which statements about sulfur dioxide is true about its polarity and its bond angle. A Sulfur dioxide is polar and has a bond angle of 90o exactly. B Sulfur dioxide is non-polar and has a bond angle of 104o approximately. C Sulfur dioxide is polar and has a bond angle of 118o approximately. D Sulfur dioxide is non-polar and has a bond angle of 180o exactly 9 Cervonic acid is an omega-3 fatty acid. cervonic acid Which type of intermolecular force will operate between the hydrocarbon chains of cervonic acid? A covalent bonding B hydrogen bonding C instantaneous dipole-induced dipole D permanent dipole-permanent dipole 10 Which compound has the most negative lattice energy? A Rubidium fluoride B Rubidium oxide C Potassium fluoride D Potassium oxide

7 ASRJC JC2 Prelim 2025 8873/H1 [Turn Over 11 Which equation describes the reaction whose ΔH is the standard enthalpy of formation of water at 298 K? A H2(g) + ½ O2(g) H2O(l) B H2(g) + ½ O2(g) H2O(g) C 2H(g) + O2(g) H2O(l) D H+(aq) + OH─(g) H2O(l) 12 Which pairs of enthalpy changes will always have the same sign, both negative or both positive? 1 Enthalpy change of combustion and enthalpy change of neutralisation 2 Enthalpy change of formation and lattice energy 3 Bond energy and enthalpy change of combustion A 1, 2 and 3 B 1 and 3 C 2 and 3 D 1 only 13 Using bond energy values from the Data Booklet, what is the standard enthalpy change of formation of hydrazine, N2H4(g)? N N H H H H hydrazine A +96 kJ mol–1 B –96 kJ mol–1 C +250 kJ mol–1 D –250 kJ mol–1

8 ASRJC JC2 Prelim 2025 8873/H1 14 Compound K decomposes by a first order kinetics. At the start of the reaction, the concentration of K was 0.960 mol dm −3. This concentration decreased to 0.240 mol dm−3 after 100 minutes. How many minutes will it take for the concentration of K to decrease from 0.80 mol dm−3 to 0.10 mol dm−3? A 48 min B 50 min C 100 min D 150 min 15 The graph shows how the initial rate of reaction varies for an enzyme catalysed reaction as the substrate concentration changes. Which statement correctly describe the situation when [substrate] = x? A The initial rate is dependent on [substrate]. B There are no more enzyme active sites available. C The enzyme lost its catalytic function. D The order of reaction with respect to substrate is 1. [substrate] initial rate x 0

9 ASRJC JC2 Prelim 2025 8873/H1 [Turn Over 16 Four successive elements, W, X, Y and Z, from the third period of the Periodic Table, were separately heated in dry oxygen. The table shows the observations made during these reactions. element observation W X Y Z Very vigorous reaction forming oxide Vigorous reaction first forming oxide, oxide layer prevents further reaction Slow reaction forming oxide Vigorous reaction forming mixture of oxides Which elements are respectively W, X, Y and Z? A Al, Si, P, S B Na, Mg, Al, Si C Mg, Al, Si, P D Si, P, S, Cl 17 Molecule G contains two elements, one fro