RVHS Prelim H1 Chemistry P1 QP

River Valley High School 8873/01/PRELIMS/25 2025 JC2 Preliminary Examination [Turn over RIVER VALLEY HIGH SCHOOL JC 2 PRELIMINARY EXAMINATION CANDIDATE NAME CLASS 2 4 J CENTRE NUMBER S INDEX NUMBER 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. Do not use staples, paper clips, glue or correction fluid. Write your name, class , centre number and index number 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 12 printed pages.

2 River Valley High School 8873/01/PRELIMS/25 2025 Preliminary Examination 1 Which of the species in their gaseous state shown below will be deflected by the largest angle in an electric field? A 11B3+ B 9Be2+ C 1H2 D 4He2+ 2 What is the electronic configuration of an element with a second ionisation energy higher than that of each of the elements on either side of it in the Periodic Table? A 1s22s22p63s2 B 1s22s22p63s23p1 C 1s22s22p63s23p2 D 1s22s22p63s23p3 3 Use of the Data Booklet is relevant to this question. High concentrations of ozone, O3, in the atmosphere at sea-level are dangerous. An acceptable concentration of O3 is 8.00 × 10−9 g cm−3. How many molecules of ozone would be present in 1 cm 3 of air at this concentration of O3? [L = Avogadro constant] A 98.00 10 48 L−   C 98.00 10 48 L − B 98.00 10 48 L −  D 98.00 10 48 L− 4 When 20 cm 3 of a gaseous organic compound w as completely burnt in 120 cm³ of oxygen, there was a contraction of 50 cm³. On further treatment with aqueous potassium hydroxide, the volume decreased by 60 cm³. Given that all volumes are measured at room temperature and pressure, what is the formula of the organic compound? A C2H2 B C2H4 C C3H6 D C3H8

3 River Valley High School 8873/01/PRELIMS/25 2025 Preliminary Examination [Turn over 5 Which equation shows a reaction in which one or more co -ordinate (dative covalent) bonds are formed? A N2 + 3H2 → 2NH3 B H2 + F2 → 2HF C Al2Cl6 → 2AlCl3 D NH3 + HCl → NH4Cl 6 Use of the Data Booklet is relevant to this question. Why is the boiling point of hydrogen sulfide greater than that of fluorine? A A molecule of hydrogen sulfide has more electrons than a molecule of fluorine. B Molecules of hydrogen sulfide form hydrogen bonds, those of fluorine do not. C Molecules of hydrogen sulfide has stronger permanent and induced dipoles than those of fluorine. D The molecules of fluorine are polar, but those of hydrogen sulfide are non - polar. 7 Some physical properties of four substances that are crystalline in the solid state are given below. Which substance is a simple molecular solid at room temperature? melting point/ C solubility in water at 25 C/ g per 100 g of water solubility in tetrachloromethane at 25 C A 0 very soluble insoluble B 112 0.03 very soluble C 801 36 insoluble D 1085 insoluble soluble

4 River Valley High School 8873/01/PRELIMS/25 2025 Preliminary Examination 8 Use of the Data Booklet is relevant to this question. When 0.860 g of ethanol undergoes complete combustion below a beaker containing 300 g of water, the temperature of the water rises by 18 °C. The theoretical enthalpy change of combustion of ethanol is –1367 kJ mol–1. What is the efficiency of the process? A 2% B 7% C 31% D 88% 9 Which compound has the most negative lattice energy? A Rubidium fluoride B Rubidium oxide C Potassium fluoride D Potassium oxide 10 For which of the following reaction s is the enthalpy change of reaction endothermic? 1 H2SO4(aq) + 2NaOH(aq) → Na2SO4(aq) + 2H2O(l) 2 Cl2(g) → 2Cl(g) 3 Mg(g) → Mg+(g) + e– 4 C(s) + O2(g) → CO2(g) A 2 and 3 only B 1 and 4 only C 3 and 4 only D 2, 3 and 4 11 The half–life of a radioactive isotope P is twice that of another radioactive isotope Q. In a sample of rock, it is found that the number of atoms of Q is 4 times that of P. What will be the ratio of the number of atoms of P to the number of atoms of Q in the rock after two half–lives of P? A B C D 1 16 1 4 1 2 1

5 River Valley High School 8873/01/PRELIMS/25 2025 Preliminary Examination [Turn over 12 The distribution of the number of molecules with energy E is given in the sketch for two temperatures, T1 and a higher temperature T2. The letters P, Q, R refer to the separate and differently shaded areas. The activation energy is marked on the energy axis. Which expression gives the fraction of the molecules present which have at least the activation energy at the higher temperature T2? A B C D 13 Which statements explains why the introduction of a catalyst leads to an increase in the rate of reaction? 1 The catalyst alters the mechanism of the reaction. 2 The proportion of molecules with energies above the activation energy increases. 3 The average kinetic energy of the molecules increases. A 1 and 2 only B 1 and 3 only C 2 and 3 only D 1, 2 and 3 Q P QR P + QR PQ + + QR P Q R + ++ region P region Q region R Legend Number of molecules with energy E T1 T2 energy E activation energy T2 > T1

6 River Valley High School 8873/01/PRELIMS/25 2025 Preliminary Examination 14 Consider the following equilibrium system: X(s) + 2Y(g)  W(g) + 3Z(s) H > 0 Which of the following statements is correct? change made position of equilibrium A add solid Z(s) shifts to the left B reduce the temperature shifts to the left C increase the concentration of W(g) shifts to the right D increase the volume of the reaction vessel shifts to the right 15 Contact process is a method of producing high concentrations of sulfuric acid for industrial applications. It involves reacting sulfur dioxide with excess oxygen to form sulfur trioxide. 2SO2(g) + O2(g)  2SO3(g) H = −196 kJ mol−1 The reaction is carried out at 450 C and 1 atm. Vanadium(V) oxide is also used. Which of the following statements is correct? A A low pressure of 1 atm is used to increase the percentage of SO 3 in the equilibrium mixture. B A high temperature of 450 C is used to increase the rate of the forward reaction to generate a higher yield of SO3. C Vanadium(V) oxide is added to decrease the activation energy of the forward reaction. D Vanadium(V) oxide is added to increase the percentage of SO 3 in the equilibrium mixture.

7 River Valley High School 8873/01/PRELIMS/25 2025 Preliminary Examination [Turn over 17 Which statement about the chlorides of Period 3 elements is incorrect? A The pH of the solutions of chlorides generally increases across the period. B The extent of hydrolysis of the chlorides from MgCl2 to SiCl4 increases. C When limited amount of water is added to the covalent chlorides, they give acidic white fumes. D Adding NaOH(aq) to a solution of AlCl3 produces a white precipitate which is soluble in an excess of NaOH. 18 Which statement explains why HC l has a higher thermal stability than HBr and HI? A HCl has the strongest intermolecular forces of attraction. B The HCl bond h