2023 XMS P2 PRELIM QP

3 6092/Chemistry/Paper 2/2023 Prelim Exam For Examiner’s Use Section A Answer all questions in this section in the spaces provided. The total mark for this section is 50. A1 The diagram shows part of the Periodic Table. Answer the questions using only the elements shown in the diagram. Each element may be used once, more than once or not at all. Write the symbol for an element which: (a) (i) forms an ion of type X2−, ……………………………………………………………………………………. [1] (ii) is a diatomic green gas at room temperature, ……………………………………………………………………………………. [1] (iii) is a gas used for weather balloons, ……………………………………………………………………………………. [1] (iv) is a gas which occupies 78% by volume of dry air, ……………………………………………………………………………………. [1] (v) can have lubricating properties. ……………………………………………………………………………………. [1] (b) Modern chemists have discovered that some noble gases can form compounds. A 1.000 g sample of one such compound is found to contains 0.549 g of xenon, 0.134 g of oxygen and 0.317 g of fluorine. (i) Calculate the empirical formula of this compound. [2]

4 6092/Chemistry/Paper 2/2023 Prelim Exam For Examiner’s Use (ii) What additional information is needed to deduce the molecular formula of this compound? ……………………………………………………………………………………. [1] (c) Draw a ‘dot -and-cross’ diagram to show the bonding in a molecule of oxygen . Show the outer electrons only. [2] (d) Aluminium and sulfur can react with oxygen to form oxides. Suggest one difference in physical property and one difference in chemical property between the oxide of aluminium and the oxide of sulfur. physical property ………………………………………………………………………………………..…. ………………………………………………………………………………………..…. chemical property ………………………………………………………………………………………..…. ………………………………………………………………………………………..…. [1] [1] [Total: 12]

5 6092/Chemistry/Paper 2/2023 Prelim Exam For Examiner’s Use A2 (a) A student investigated the reaction between different metals and hydrochloric acid. He reacted 1.5 g of iron and 1.5 g of zinc separately with excess hydrochloric acid. Fe(s) + 2HCl(aq) → FeCl2(aq) + H2(g) Zn(s) + 2HCl(aq) → ZnCl2(aq) + H2(g) Every 10 seconds, he measured the volume of gas in a gas syringe. The graph shows the results. (i) Explain why 1.5 g of iron produces more hydrogen gas than 1.5 g of zinc. ……………………………………………………………………………………. ……………………………………………………………………………………. ……………………………………………………………………………………. [2] (ii) Explain how you can tell from the graph which is the more reactive metal. ……………………………………………………………………………………. [1]

6 6092/Chemistry/Paper 2/2023 Prelim Exam For Examiner’s Use (iii) When the reaction stops, the student adds aqueous sodium hydroxide drop by