2022 Cedar girls secondary school Prelim Chemistry Paper 1

CEDAR GIRLS’ SECONDARY SCHOOL Preliminary Examination 2022 Secondary Four [Turn over CHEMISTRY 6092/01 Paper 1 15 September 2022 1 hour Additional Materials: OMR Form INSTRUCTIONS TO CANDIDATES Do not open this booklet until you are told to do so. Write your name, class and index number on the answer sheet in the spaces provided unless this has already been done for you. There are forty questions in 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 very carefully the instructions on the answer sheet. INFORMATION FOR CANDIDATES 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. A copy of the Periodic Table is provided on page 19. The use of an approved scientific calculator is expected, where appropriate. This document consists of 19 printed pages and 1 blank page.

2 1 At room temperature and pressure, which gas diffuses faster than nitrogen gas? A argon B fluorine C methane D oxygen 2 The diagram shows the fractional distillation of two liquids, R and S. R has a boiling point of 80 oC and S has a boiling point of 110 oC. Which statement is correct when the thermometer shows 80 oC? 1 The liquid left in the flask contains more S than R. 2 The vapour at point Y only contains R. 3 The temperature at X is higher than the temperature at Y. A 1, 2 and 3 B 1 and 2 only C 1 only D 2 and 3 only thermometer

[Turn over 3 3 The diagram shows the chromatogram obtained by the analysis of a dye mixture. The distances travelled by three spots are shown in the diagram. What is the Rf of the most soluble dye? A 0.20 B 0.80 C 1.00 D 1.25 4 The equation shows the reaction between calcium hydroxide and dilute nitric acid. Ca(OH)2 + 2HNO3 → Ca(NO3)2 + 2H2O An experiment is conducted to determine the solubility of calcium hydroxide in water at room temperature. 25.0 cm3 of a saturated solution of freshly prepared calcium hydroxide is titrated against dilute nitric acid. Besides the conical flask, what other apparatus is needed for the titration? A beaker and pipette B burette and measuring cylinder C burette and pipette D burette and stirrer 10 cm 8 cm 6 cm 2 cm solvent front start line

4 5 The apparatus below is used to obtain a small sample of dry nitrogen gas from a sample of gas contaminated with hydrogen chloride. Which row correctly describes the reagents in flask P and in flask Q? flask P flask Q A ethanoic acid concentrated sulfuric acid B water aqueous sodium hydroxide C aqueous sodium hydroxide concentrated sulfuric acid D concentrated sulfuric acid aqueous sodium hydroxide 6 Propane and butane are usually stored as liquids. They are produced by compressing the gases in separate vessels with the same volume . Assuming that the same mole equivalent of propane and butane is used, which of the following statements is true? 1 Energy will be released to the surroundings during compression. 2 Liquid propane will be heavier after all the gaseous propane have been compressed. 3 Liquid butane has a higher density than liquid propane. 4 The molecules in liquid propane and butane are randomly arranged in the vessel. A 1, 2 and 3 only B 1, 2 and 4 only C 1, 3 and 4 only D 2, 3 and 4 only dry nitrogen nitrogen gas contaminated with hydrogen chloride flask P flask Q

[Turn over 5 7 The following graphs are obtained by cooling four liquids, A, B, C and D. Which of the graphs shows the cooling curve of a pure liquid? 8 An element consists of four isotopes. The graph shows the relative abundances of the four isotopes. The relative abundance is a measure of the percentage by mass of the isotope of a particular relative atomic mass. What is the relative atomic mass of the element? A 22.8 B 23.0 C 91.3 D 92.0 temperature time B temperature time C temperature time D temperature time A percentage relative abundance relative atomic mass

6 9 The following molecules all contain covalent bonds. 1 ammonia 2 carbon dioxide 3 oxygen Which of the molecules contains only single covalent bonds? A 1, 2 and 3 B 1 and 2 only C 1 only D 2 and 3 only 10 The diagrams show three separate experiments involving ammonium compounds. In which experiment is ammonia gas produced? A 1, 2 and 3 B 1 only C 2 only D 3 only 11 Copper is a metal. The structure of copper is described as a lattice of positive ions in a sea of electrons. Which statement about copper is correct? 1 Copper conducts electricity because the electrons are free to move. 2 Copper conducts heat because the positive ions are free to move. 3 Copper has a high melting point due to strong covalent bonds. 4 Copper ions are held together because of their attraction for each other. A 1, 2 and 3 only B 1 only C 2, 3 and 4 only D 2 and 3 only

[Turn over 7 12 36S2– and 37Cl– are ions of sulfur and chlorine isotopes. What do the ions have in common? A Both ions contain the same number of nucleons in their nuclei. B Both ions have electronic configuration 2, 8, 6. C Both ions have more electrons than neutrons. D Both ions have 20 neutrons in their nuclei. 13 Which statement best explains why 1 mole of hydrogen atoms has approximately the same mass as 1 mole of protons? A A hydrogen atom is made up of one proton only. B An electron has zero mass. C One mole of any substance has the same mass. D The mass of a proton is much greater than the mass of an electron. 14 Bromobutane, C4H9Br, can be made from butanol using the reaction shown. C4H9OH + HBr → C4H9Br + H2O In an experiment, 10 g of butanol produced 12 g of bromobutane. What is the percentage yield of bromobutane? [Mr: C4H9OH, 74; C4H9Br, 137] A 45% B 54% C 65% D 83% 15 The combustion reaction between hydrogen gas and oxygen gas is shown. 2H2 (g) + O2 (g) → 2H2O (g) A mixture of 24 dm3 of hydrogen gas and 100 dm3 of oxygen gas was ignited. The reaction mixture was cooled to room temperature and pressure. What would be the total volume of gases remaining at the end of the reaction? A 24 dm3 B 66 dm3 C 88 dm3 D 124 dm3

8 16 The compound SO2Cl2 reacts with water according to the following equation. SO2Cl2 + 2H2O → H2SO4 + 2HCl How many moles of lithium hydroxide will neutralize the solution produced by 0.25 mol of SO2Cl2 and 1.0 mol of water? A 0.75 mol B 1.00 mol C 1.50 mol D 2.00 mol 17 Which of the following processes does not cause the surrounding temperature to rise? A dissolving ammonium chloride in water B mixing potassium hydroxide with nitric acid C reacting hydrogen with nitrogen to form ammonia D rusting of iron 18 The decreasing order of reactivity of four metals is as follows: T is most reactive, followed by W, V and U. These four metals are extracted from their ores in three different ways: