JPJC 2024 H2 Chemistry WA1

© Jurong Pioneer Junior College [Turn Over JURONG PIONEER JUNIOR COLLEGE 2024 JC1 H2 WA1 (9476) REVISION PAPER 1 Instructions: You are advised to complete this practice in one sitting under examination conditions (i.e. timed conditions, quiet and undisturbed, with no reference to materials). Upon completion, mark your work against the solutions to gauge your level of competency. You will need writing materials (including 2B pencil), calculator and a Data Booklet. Name : __________________________________ Lack 3sf in final ans Class : 26S n Missing/wrong units in final ans Date : __________________ Final score 30 Duration: 55 minutes INSTRUCTIONS TO CANDIDATES Answer ALL questions in the space provided. All numerical answers should be given to 3 significant figures, where appropriate. A Data Booklet is provided. SECTION A (25 marks) 1 (a) Copper is a d-block element. Write the electronic configuration of a Cu+ ion. ………………………………………..……………………………………………………. [1] (b) Copper and ice are crystalline solids. (i) Copper has a melting point of 1028 C. Explain this property of copper by referring to its structure and bonding. ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… [1] (ii) Draw a labelled diagram to show the significant force of attraction between two water molecules. Include the name of the attraction in your diagram. [2] [Total: 4]

2 © Jurong Pioneer Junior College 9476/J1 WA1 Revision Paper 1/2026 2 (a) Explain the increase in atomic radius down the group. ……………………………………………………………………………………………… ……………………………………………………………………………………………… ……………………………………………………………………………………………… ……………………………………………………………………………………………… ……………………………………………………………………………………………… [2] (b) The second to fifth ionisation energies of three consecutive elements in the third period of the Periodic Table are given in Table 2.1. The symbols used for reference are not the actual symbols of the elements. Table 2.1 element ionisation energies / kJ mol1 second third fourth fifth W 1450 7740 10 500 13 600 X 1820 2740 11600 14 800 Y 1580 3230 4360 16 100 (i) Write an equation to represent the second ionisation energy of element W. ……………………………………………………………………………………… [1] (ii) State and explain the group number of element X. group number ………….. explanation ……………………………………………………………………….. ....................................................................................................................... ……………………………………………………………………………………… [2] (iii) Explain why the second ionisation energy of element Y is less than that of element X. ……………………………………………………………………………………… ……………………………………………………………………………………… ……………………………………………………………………………………… [1] [Total: 6]

3 © Jurong Pioneer Junior College 9476/J1 WA Revision Paper 1/2026 [Turn Over 3 40 cm 3 of gaseous hydrocarbon, C xHy, was exploded with excess oxygen. A contraction in volume of 100 cm 3 occurred. On treating the products with aqueous sodium hydroxide, a further contraction in volume of 120 cm3 occurred. Given that all gas volumes were measured at room temperature and pressure, deduce the molecular formula of the hydrocarbon. [2] [Total: 2]

4 © Jurong Pioneer Junior College 9476/J1 WA1 Revision Paper 1/2026 4 Hydroxylamine, NH 2OH, is commonly used in photography developing solution. Prolonged exposure to NH 2OH by photography developers might cause irritation to their respiratory tract. A scientist performed the following experiment to determine the concentration of NH2OH found in a sample of developing solution. 200 cm3 of NH 2OH solution was added to 50.0 cm 3 of 0.120 mol dm –3 acidified iodine solution, which is in excess. The reaction occurs according to the equation given below. 2NH2OH + 2I2  N2O + H2O + 4I– + 4H+ (a) Write a half-equation for the conversion of NH2OH to N2O. ……………………………………………………………………………………………… [1] (b) A 25.0 cm 3 sample of the resulting reaction mixture was titrated against 0.0150 mol dm–3 Na2S2O3. I2(aq) + 2S2O32–(aq)  2I(aq) + S4O62–(aq) The end-point is reached when 22.50 cm3 of Na2S2O3(aq) has been added. (i) Calculate the amount of iodine remaining in the 25.0 cm 3 sample of the resulting reaction mixture. [1] (ii) Calculate the amount of iodine reacted with NH2OH. Hence, determine the concentration of NH 2OH in 200 cm 3 sample of the photography developing solution. [3] [Total: 5]

5 © Jurong Pioneer Junior College 9476/J1 WA Revision Paper 1/2026 [Turn Over 5 The elements sodium to chlorine, in Period 3, all form oxides. (a) Draw a diagram to show the shape of the molecule of each of the oxides, SO 3 and Cl2O. Name the shape of each molecule. SO3 Cl2O shape: …………………………………… shape: ………………………………… [3] (b) In terms of structure and bonding, explain why (i) the melting point of MgO is higher than that of Na2O. ……………………………………………………………………………………….. ……………………………………………………………………………………….. ……………………………………………………………………………………….. ……………………………………………………………………………………….. ……………………………………………………………………………………….. [2] (ii) the boiling point of SO3 is higher than that of SO2. ……………………………………………………………………………………….. ……………………………………………………………………………………….. ……………………………………………………………………………………….. ……………………………………………………………………………………….. ……………………………………………………………………………………….. [2] (c) Nitrogen, an element in Period 2, can form dinitrogen trioxide, N2O3. N2O3 contains a NN bond. Draw the ‘dot-and-cross’ diagram for N2O3. Use  for electrons from nitrogen. Use  for electrons from oxygen. [1] [Total: 8]

6 © Jurong Pioneer Junior College 9476/J1 WA1 Revision Paper 1/2026 Section B (5 marks) 6 Beams of charged particles are deflected by an electric field. In an experiment, protons are deflected by an angle of +15°. In another experiment under identical conditions, particle Y is deflected by an angle of –5°. What could be the composition of particle Y? number of protons number of neutrons number of electrons 1 1 2 2 2 3 3 5 3 4 5 1 A 1 only B 1 and 2 C 1 and 3 D 2 and 3 ( ) 7 An element Q forms a diatomic molecule, Q 2, which has a relative molecular mass, x. The Avogadro constant is L. How many atoms are present in 1.0 g of Q2? A Lx B 2Lx C 2Lx D 2Lx ( ) 8 Use of the Data Booklet is relevant to this question. When aqueous hydrogen peroxide, H 2O2, is mixed with acidified potassium dichromate( VI), K2Cr2O7, there is a colour change from orange to green. When aqueous hydrogen peroxide is added to acidified potassium iodide solution, there is a colour change from colourless to brown. The oxidation number of oxygen in H2O2 is 1. What are the oxidation numbers of oxygen after the reactions with potassium dichromate( VI) and potassium iodide? after reaction with potassium dichromate(VI) after reaction with potassium iodide A 2 2 B 2 0 C 0 2 D 0 0 ( )

7 © Jurong Pioneer Junior College 9476/J1 WA Revision Paper 1/2026 [Turn Over 9 Glycine is an -amino acid which is crucial in the synthesis of human proteins. It has the following structure. What are the values of the bond angles x, y and z in a molecule of glycine? x y z A 90 90 180 B 107 120 180 C 90 90 105 D 107 120 105 ( ) 10 Silicon carbide, SiC, has the same structure as silicon( IV) oxide, SiO2. Hence, SiC is used as a major industrial abrasive, and a refractory material which is resistant to decomposition by heat. Which type of structure explains these properties? A A simple molecular structure with covalent bonds between silicon and car