2024 ACJC Prelim H1 Chem Paper 1 QP

This document consists of 12 printed pages. Anglo-Chinese Junior College JC2 Preliminary Examination Higher 1 CHEMISTRY Paper 1 Multiple Choice Additional Materials: Multiple Choice Answer Sheet Data Booklet 8873/01 9 September 2024 1 hour READ THESE INSTRUCTIONS FIRST Write in soft pencil. Do not use staples, paper clips, glue or correction fluid. Write your name, Centre number and index number on the Answer Sheet in the spaces provided unless this has been done for you. 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.

2 © ACJC 2024 8873/Preliminary Examination/2024 [Turn over 1 Carbon sulfide, CS2, is a volatile flammable liquid used in the manufacture of cellophane. On combustion, CS2 is oxidised as follows. CS2(g) + 3O2(g) CO2(g) + 2SO2(g) A 20 cm3 sample of carbon disulfide vapour is ignited with 100 cm 3 of oxygen. The final volume of gas after burning is treated with an excess of aqueous alkali. What percentage of this final volume dissolves in the alkali? [All volumes are measured at the same temperature and pressure.] A 20% B 40% C 60% D 80% 2 2 mol of n itric acid, HNO 3, a powerful oxidising agent , reacts with 3 mol of hydrogen sulfide, H2S, to form three products, one of which is water. In this reaction, the oxidation number of nitrogen decreases by 3. What are the other two products of this reaction? A N2O2 and H2SO4 C NO and SO2 B NO and S D N2O2 and H2SO3 3 Consider the following half-equations. MnO4– + 8H+ + 5e– Mn2+ + 4H2O Fe2+ Fe3+ + e– C2O42– 2CO2 + 2e– What volume of 0.01 mol dm–3 KMnO4 is required to oxidise 15 cm3 of an acidified solution of 0.01 mol dm–3 FeC2O4? A 3 cm3 B 6 cm3 C 9 cm3 D 15 cm3

3 © ACJC 2024 8873/Preliminary Examination/2024 [Turn over 4 Use of the Data Booklet is relevant to this question. The table shows statements made by three students about the s, p and d electrons in the atoms of the element with atomic number 30. student statement X There are s electrons in 4 different quantum shells. Y There are p electrons in 2 different quantum shells. Z The d electrons have the same principal quantum number as the outermost s electrons. Which students are correct? A X, Y and Z B X and Y C Y and Z D X and Z 5 Alpha particles, He 2+, are commonly emitted by larger radioactive nuclei. The path of a mixture of an unknown ion, A, O2+ and alpha particles after passing through an electric field is as shown below. What could ion A be? A H+ B Be2+ C C+ D Al3+ 6 Which molecular structure has the smallest overall dipole? A C B D source alpha particle O2+ A

4 © ACJC 2024 8873/Preliminary Examination/2024 [Turn over 7 Some car paints contain small flakes of silica, SiO2. In the structure of solid SiO2 • each silicon atom is bonded to x oxygen atoms, • each oxygen atom is bonded to y silicon atoms, • each bond is a z type bond. What is the correct combination of x, y and z in these statements? x y z A 2 1 covalent B 2 1 ionic C 4 2 covalent D 4 2 ionic 8 What is the order of increasing volatility at room temperature? 1 2,3-dimethylbut-2-ene 2 cis-hex-3-ene 3 trans-hex-3-ene A 2, 3, 1 C 3, 2, 1 B 1, 2, 3 D 1, 3, 2 9 Which statement can be explained in terms of hydrogen bonding? 1 The apparent relative molecular mass of ethanoic acid in benzene is 120. 2 HF2‒ is formed when HF is dissolved in molten NaF. 3 The boiling point of propanoic acid is higher than ethanoic acid. 4 Ice is less dense than water. A 1, 2 and 3 C 2, 3 and 4 B 1, 3 and 4 D 1, 2 and 4 10 Elements A and B are both in Period 3. Element A has the smallest atomic radius in Period 3. There are only two elements in Period 3 which have a higher melting point than element B. Elements A and B react together to form compound C. Which compound could be C? A Al2S3 B MgCl2 C Na2S D PCl5

5 © ACJC 2024 8873/Preliminary Examination/2024 [Turn over 11 Use of the Data Booklet is relevant to this question. The properties of chlorine, bromine (denoted as X2 in their elemental state) and their compounds are compared. Which property is smaller for bromine than for chlorine? 1 pressure to liquefy X2(g) at the same temperature 2 oxidising power of X2 3 first ionisation energy of X(g) A 1 and 2 C 2 and 3 B 1 and 3 D 1, 2 and 3 12 An element in the Period 2 of the Periodic Table often shows similar properties to the element a group higher in the Period 3. This is known as a diagonal relationship between the elements and their compounds. An example of a diagonal relationship is between beryllium and aluminium. Which statement about BeO and BeCl2 is incorrect? A BeO is amphoteric in nature but BeCl2 is acidic in nature. B BeO is predominantly covalent but BeCl2 is predominantly ionic. C BeO is insoluble in water but BeCl2 partially hydrolyses in water. D BeO has a giant lattice structure but BeCl2 has a simple lattice structure. 13 Nitromethane can be used as a fuel additive for motor racing and rockets. 4CH3NO2(g) + 3O2(g) 4CO2(g) + 6H2O(l) + 2N2(g) Values of standard enthalpy changes of formation are in the table. compound ΔHf / kJ mol–1 CH3NO2(g) –113 CO2(g) –394 H2O(l) –286 What is the enthalpy change of this reaction? A –3744 kJ mol–1 C –2840 kJ mol–1 B +3744 kJ mol–1 D +2840 kJ mol–1

6 © ACJC 2024 8873/Preliminary Examination/2024 [Turn over 14 Use of the Data Booklet is relevant to this question. Butane is used as a fuel for cooking. When 0.025 mol of butane was burnt under a vessel containing 250 g of water, it was found that the temperature of the water rose by 50 °C. Which value for the enthalpy change of combustion of butane is given by these results? A –2090 kJ mol–1 C –13 500 kJ mol–1 B –2100 kJ mol–1 D –13 580 kJ mol–1 15 The lattice energies of the caesium chloride, caesium fluoride, sodium chloride and sodium fluoride are given below in the options, not necessarily in this order. Which value corresponds to the lattice energy of caesium chloride? A –661 kJ mol–1 C –780 kJ mol–1 B –740 kJ mol–1 D –918 kJ mol–1 16 For a reaction 2U(aq) + 3V(aq) 2W(aq), the rate equation is rate = k[U]2[V]. reaction temperature / °C initial [U] / mol dm–3 initial [V] / mol dm–3 initial rate / mol dm–3 s–1 1 25 1.0 1.0 r 2 55 0.5 0.5 q It is also given that the rate doubles for every 10 °C rise in temperature. What is the initial rate of reaction 2, q? A 0.5r B r C 2r D 4r 17 A radioactive element has two isotopes, X and Y, with half –lives of 2 min and 6 min respectively. An experiment starts with z times as many atoms of X than Y. Af