2023 XMS P1 PRELIM QP

3 6092/Chemistry/Paper 1/2023 Preliminary Exam 1 The diagram shows how to obtain pure water from salt solution. Where do water molecules lose energy? 2 A student sets up the following apparatus to collect a gas. What is the possible identity of the gas and drying agent? gas drying agent A hydrogen chloride calcium oxide B hydrogen chloride concentrated sulfuric acid C ammonia concentrated sulfuric acid D ammonia calcium oxide

4 6092/Chemistry/Paper 1/2023 Preliminary Exam 3 Strontium is used in fireworks to produce crimson flames. The graph below shows the relative masses of three naturally occurring isotopes of strontium and their percentages in a sample of strontium. What is the relative atomic mass of naturally occurring strontium? A 86.5 B 87.4 C 87.7 D 88.0 4 The Rf values for the colours, E, F, G and H, in four different solvents are shown in the table. solvent water ethanol propanone hexane E 0.3 0.5 0.6 0.5 F 0.3 0.7 0.9 0.2 G 0.7 0.8 0.3 0.1 H 0.1 0.6 0.6 0.2 Which solvent could be used to separate a mixture of all four colours E, F, G and H? A water B ethanol C propanone D hexane relative isotopic mass percentage of isotope in sample 85 86 87 88

5 6092/Chemistry/Paper 1/2023 Preliminary Exam 5 Hydrogen sulfide, H2S, is a colourless and poisonous gas. The melting point of hydrogen sulfide is −82 C and the boiling point is −60 C. Which statement correctly describes the particles of hydrogen sulfide at −75 C? A closely packed, moving freely B closely packed, vibrating slightly C far apart, moving freely D far apart, vibrating slightly 6 An ion contains 8 protons, 8 neutrons and 10 electrons. What is its nucleon number? A 8 B 16 C 18 D 26 7 The diagram shows the structure of a covalent compound containing the element hydrogen, H, and the unknown elements X, Y and Z. How many outer electrons do each of the three elements, X, Y and Z possess? X Y Z A 3 6 5 B 4 2 6 C 4 6 5 D 4 6 3

6 6092/Chemistry/Paper 1/2023 Preliminary Exam 8 Whisky is a beverage composed of mainly water and ethanol. Ethanol boils at 78 °C. A sample of Scotch Whisky that is made up of 40% of ethanol by volume is distilled using fractional distillation. Which graph shows the change in concentration of ethanol in the sample as the distillation proceeds? A B C D 9 Q is an element in the Periodic Table. Which of the following represents an isotope of Q35 81 ? A Q37 81 B Q33 81 C Q35 79 D Q33 79 10 Which method is most suitable for preparing calcium nitrate crystals? A Add excess calcium carbonate to nitric acid. Filter and crystallise the filtrate. B Add equal volumes of aqueous calcium chloride and aqueous sodium nitrate together and filter. C Add excess nitric acid to calcium oxide. Crystallise the mixture. D Titrat