CJC 2026 Prelim P1 QP

1 9476/01 CJC JC2 Preliminary Examination 2026 [Turn over CANDIDATE NAME CLASS 2T CHEMISTRY 9476/01 Paper 1 Multiple Choice 17 September 2026 1 hour You must answer on the multiple choice answer sheet. You will need: Multiple choice answer sheet Data booklet Soft clean eraser Soft pencil (type B or HB is recommended) INSTRUCTIONS • 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 multiple choice answer sheet. • Follow the instructions on the multiple choice answer sheet. • Write your name, class and NRIC number on the multiple choice answer sheet in the spaces provided unless this has been done for you. • Do not use correction fluid or tape. • You may use an approved calculator. INFORMATION • The total mark for this paper is 30 • Each correct answer will score one mark. • Any rough working should be done on this question paper. This document has 12 pages. Any blank pages are indicated. Catholic Junior College JC 2 Preliminary Examinations Higher 2

2 1 Which statement correctly explains the trends in ionisation energies in the Periodic Table? A Oxygen has a lower first ionisation energy than nitrogen because the paired 2p electrons experience repulsion with each other. B Iron and cobalt have first ionisation energies that only differ by 5 kJ moI -1 because they both lose an electron from a 3d orbital. C The first ionisation energies increase from sulfur to argon across Period 3 because each successive element has one more electron in the valence shell. D The second ionisation energy of nitrogen is greater than the first ionisation energy of oxygen because the species involved are isoelectronic but oxygen has the greater nuclear charge. 2 Which of the following statements explains why graphite has a high melting point? 1 The electrons in graphite are delocalised. 2 The intermolecular forces of attractions between graphite molecules are strong. 3 Graphite has an extensive network of strong covalent bonds between carbon atoms. A 1 and 3 B 1 only C 2 and 3 D 3 only 3 Which of the following species is planar? 1 XeF4 2 H2S 3 SO3 4 PCl4+ A 1,2 and 3 only B 1 and 3 only C 1 and 4 only D 3 only 4 The table shows the boiling points of three alkanes. isomers boiling point / C hexane 68.7 2–methylpentane 60.0 2,2–dimethylbutane 49.7 Which is the factor that causes the difference in boiling point? A different relative molecular masses B different number of carbon–carbon bonds C strength of intermolecular hydrogen bonding D extensiveness of intermolecular instantaneous dipole–induced dipole attractions

3 9476/01 CJC JC2 Preliminary Examination 2026 [Turn over 5 The successive ionisation energies, in kJ mol–1, of elements A and B are given below, starting with the first ionisation energy. A 580 1820 2740 11600 14800 18400 23300 B 940 2050 2970 4140 6590 7880 14900 Which statements about elements A and B are true? 1 The first ionisation energy of A is lower than that of the element preceding it in the Periodic Table. 2 A and B form a compound with the formula A3B2. 3 A has a giant metallic structure. A 1 and 3 only B 3 only C 2 and 3 only D 1 and 2 only 6 Use of the Data Booklet is relevant to this question. Which contains the greatest number of molecules? A 3.00 g of methyl ethanoate B 600 cm3 of helium (measured at r.t.p.) C 3.00 g of liquid bromine D 6.00 x 1021 molecules of water 7 Use of the Data Booklet is relevant to this question. When 0.006 mol of Br2(aq) was added to excess KOH(aq), it forms 0.010 mol of KBr. The other products formed in this reaction are KBrOy and H2O. What is the value of y in the formula KBrOy? A 1 B 2 C 3 D 4 No. of moles of Br2 = (30 / 1000) x 0.200 = 0.006 mol No. of moles of KBr = 1.19 / (39.1 + 79.9) = 0.010 mol Mole ratio of Br2 : KBr is 3: 5 3Br2 + ?KOH → 5KBr + KBrOy + ?H2O 3Br2 + (5+1)KOH → 5KBr + KBrOy + 3H2O 6 O 3 O 3 O Ans: C

4 8 The standard enthalpy change of formation of sulfur dioxide and sulfur trioxide are given below. ΔH  f (SO2) = –297 kJ mol–1 ΔH  f (SO3) = –396 kJ mol–1 Which of these statements are correct? 1 Sulfur dioxide is energetically less stable than sulfur trioxide. 2 The standard enthalpy change of combustion of sulfur dioxide is –99 kJ mol–1. 3 ΔH  f (SO3) – ΔH  c (SO2) has the same value as standard enthalpy change of formation of SO2. A 2 only B 1 and 3 only C 2 and 3 only D 1, 2 and 3 only 9 The Boltzmann distributions and activation energies, Ea, for a homogeneous gaseous reaction under different conditions, P and Q, are shown. What changes in conditions would result in the change from P to Q? A a decrease in temperature only B an increase in temperature only C decreasing the temperature and addition of a catalyst D increasing the temperature and addition of a catalyst Number of reactant particles with energy, E P Q Ea (Q) Energy, E Ea (P) 0

5 9476/01 CJC JC2 Preliminary Examination 2026 [Turn over 10 Nitrogen monoxide, NO, reacts with chlorine, Cl2 according to the equation: 2NO + Cl2 ⇌ 2NOCl The mechanism is as shown: Step 1: NO + Cl2 ⇌ NOCl + Cl• slow Step 2: NO + Cl• → NOCl fast Which statement about this mechanism is correct? A NOCl is an intermediate. B The chlorine radical is acting as a catalyst. C The rate equation derived from this mechanism is rate = k[NO]2[Cl]. D Step 1 has a higher activation energy than step 2. 11 The sulfur at hydrothermal vents contain small quantities of the radioactive isotope 35S. The radioactive decay of this isotope is a first order reaction with a half-life of 88 days. How many days will it take for the reactivity to fall to 1/8 of its initial value? A 44 B 88 C 176 D 264 12 Manganate(VII) ions, MnO4−, undergo a redox reaction in acidic solution with ethanedioate ions, C2O42−. 2MnO4− + 5C2O42− + 16H+ ⎯→ 2Mn2+ + 10CO2 + 8H2O The reaction is very slow at room temperature and can be catalysed by Mn2+ ions. Further studies show that in the presence of the Mn2+ catalyst, the reaction follows a first- order kinetics with respect to the MnO4− ions. Which graphs are correct? 1 [MnO4−] time (no Mn2+ added) 2 rate time (no Mn2+ added) 3 rate [MnO4−] (Mn2+ added) A 1 and 2 only B 1 and 3 only C 3 only D 1, 2 and 3 0 0 0

6 13 Haber process is the process for the manufacture of ammonia. N2(g) + 3H2(g) ⇌ 2NH3(g) ∆Ho = –92 kJ mol-1 Which of the following statements is true about the Haber process? A Increasing the partial pressure of nitrogen gas increases the equilibrium yield of ammonia B Increasing the temperature increases the equilibrium yield of ammonia C Adding a catalyst increases the equilibrium yield of ammonia and the rate of production of ammonia is faster. D Adding argon gas at constant pressure increases the equilibrium yield of ammonia 14 Magnesium, aluminium, silicon and phosphorus are consecutive elements in Period 3 of the Periodic Table. Which of the following properties generally decreases from magnesium to phosphorus? 1 Electronegativity 2 Melting point of oxides 3 Electrical conductivity 4 pH of their chloride in water A 2 only B 1 and 3 only C 2 and 4 only D 2 and 3 only 15 The compounds listed are formed from their elements. For the formation of whi