IGCSE/GCE-CHEMISTRY Particulate Nature of Matter Section-I 1. Choose the correct answer. 1. In which changes do the particles move further apart? A W and X B W and Z C X and Y D Y and Z D Z to Y 2. Diagrams X, Y and Z represent the three states of matter. Which change occurs during boiling? A X to Y B Y to Z C Z to X 3. Which change of state takes place during evaporation? A gas to liquid B liquid to gas C liquid to solid D solid to gas 4. In which process do particles move closer together but remain in motion? A condensation B diffusion C evaporation D freezing 5. The changes that occur when a substance changes state are shown below Which process, W, X, Y or Z, is occurring in the following four situations? 1 Butter melts on a warm day. 2 Water condenses on a cold surface. 3 The volume of liquid ethanol in an open beaker reduces. 4 Ice forms inside a freezer. Compiled By: Hafiz Zeeshan Khan IGCSE/GCE-CHEMISTRY 6. A sugar cube is dropped into a hot cup of tea. The tea is not stirred. Which statement explains why the tea becomes sweet? A The heated water molecules penetrate the sugar cube. B The hot tea causes the sugar to melt. C The sugar cube dissolves and its molecules diffuse. D The sugar molecules get hot and evaporate. 7. A crystal of purple potassium manganate (VII) was added to each of the beakers shown in the diagram. One beaker contained hot water and the other beaker contained cold water. In both beakers the purple color of the potassium manganate (VII) spreads out. Which result and explanation are correct? 8. Which statement is an example of diffusion? A A kitchen towel soaks up some spilt milk. B Ice cream melts in a warm room. C Pollen from flowers is blown by the wind. D The smell of cooking spreads through a house. Compiled By: Hafiz Zeeshan Khan IGCSE/GCE-CHEMISTRY 9. A few drops of perfume were spilt on the floor. A few minutes later the perfume could be smelt a few meters away. Which two processes had taken place? A distillation and condensation B distillation and diffusion C evaporation and condensation D evaporation and diffusion 10. Some cold water is poured into a conical flask and a bung inserted. The diagram shows the flask after a few minutes. A boiling and condensing B condensing and evaporating C evaporating and freezing D freezing and melting 11. The diagram shows the result of dropping a purple crystal into water Which processes take place in this experiment? Compiled By: Hafiz Zeeshan Khan IGCSE/GCE-CHEMISTRY 12. Two gas jars each contain a different gas. The gas jars are connected and the cover slips are removed. The diagram shows what happens to the particles of the gases. Which process has occurred? A chemical reaction B condensation C diffusion D evaporation 13. A liquid is heated until it boils. Which result shows that the liquid in the test-tube is pure water? A Condensation forms at the top of the test-tube. B Steam is produced. C The thermometer reads 100 °C. D There is nothing left behind in the test-tube. Compiled By: Hafiz Zeeshan Khan IGCSE/GCE-CHEMISTRY 14. An attempt was made to compress a gas and a solid using the apparatus shown. Which substance would be compressed and what is the reason for this? 15. A gas jar of bromine vapor and a gas jar of air are set up as shown in diagram 1. The glass slide is removed. Diagram 2 shows the appearance of the gas jars after one hour. Which statement explains why the bromine and air mix together? A Bromine is denser than air. B Bromine is lighter than air. C Bromine molecules moved upwards and molecules in air moved downwards. D Molecules in bromine and air moved randomly. 16. The diagram shows a cup of tea. Compiled By: Hafiz Zeeshan Khan IGCSE/GCE-CHEMISTRY Which row describes the water particles in the air above the cup compared with the water particles in the cup? 17. ‘Particles moving very slowly from an area of high concentration to an area of low concentration.’ Which process is being described above? A a liquid being frozen B a solid melting C a substance diffusing through a liquid D a substance diffusing through the air 18. Which diagram shows the process of diffusion? 19. In which substance are the particles close together and slowly moving past each other? A air B ice C steam D water Compiled By: Hafiz Zeeshan Khan IGCSE/GCE-CHEMISTRY 20. The diagrams show the arrangement of particles in three different physical states of substance X. Which statement about the physical states of substance X is correct? A Particles in state 1 vibrate about fixed positions. B State 1 changes to state 2 by diffusion. C State 2 changes directly to state 3 by condensation. D The substance in stage 3 has a fixed volume. Compiled By: Hafiz Zeeshan Khan IGCSE/GCE-CHEMISTRY Section-II 1. Kinetic theory explains the properties of matter in terms of the arrangement and movement of particles. a) Nitrogen is a gas at room temperature. Nitrogen molecules, N2, are spread far apart and move in a random manner at high speed. Compare the movement and arrangement of the molecules in solid nitrogen to those in nitrogen gas. ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… ……………………………………………………………………………………………………… …………………………………………………………………………………………………… [3] b) A sealed container contains nitrogen gas. The pressure of the gas is due to the molecules of the gas hitting the walls of the container. Use the kinetic theory to explain why the pressure inside the container increases when the temperature is increased. ………………………………………………………………………………………..………… ……..…………………………………………………………………………………………… [2] c) The following apparatus can be used to measure the rate of diffusion of a gas. The following results were obtained. Explain why nitrogen gas diffuses faster than chlorine gas. …………………………………………………………………………………………………………… …………………………………………………………………………………………………………… [2] Explain why the nitrogen gas diffuses faster at the higher temperature. .………………………………....………………………………………………………………………. Compiled By: Hafiz Zeeshan Khan [1] IGCSE/GCE-CHEMISTRY 2. Concentrated ammonia solution gives off ammonia gas. Concentrated hydrochloric acid gives off hydrogen chloride gas. Ammonia, NH3, and hydrogen chloride, HCl, are both colorless gases. Ammonia reacts with hydrogen chloride to make the white solid ammonium chloride. Apparatus set up is shown. After ten minutes a white solid forms in the tube where the gases meet. (i) Write the chemical equation for the reaction of ammonia with hydrogen chloride. ....................................................................................................................................... [1] (ii) Name the process by which the ammonia and hydrogen chloride gases move in the tube. ....................................................................................................................................... [1] (iii) At which point, A, B, C or D, does the white solid form? Explain why the white solid forms at that point. The solid forms at.............. Explanation................................................................................................................................... ..................................................................................................................................................... [3] (iv) The experiment was repeated at a higher temperature. Predict how the results of the experiment would be different. Explain your answer. ................................................................................................................................................. ................................................................................................................................................. .......................................................................................................................................…….. [3] 3. Compound X is a colorless liquid at room temperature. a) A sample of pure X was slowly heated from –5.0 °C, which is below its melting point, to 90 °C, which is above its boiling point. Its temperature is measured every minute and the results are represented on the graph. Compiled By: Hafiz Zeeshan Khan IGCSE/GCE-CHEMISTRY (i) Complete the equation for the equilibrium present in the region BC. X(s).................... (ii) What is the significance of temperature t °C? .............................................................................................................................................. [1] (iii) What is the physical state of compound X in the region EF? .............................................................................................................................................. [1] (iv) What would be the difference in the region BC if an impure sample of X had been used? ............................................................................................................................................ [1] 4. (a) Different gases diffuse at different speeds. (i) What is meant by the term diffusion? ………................................................................................................................................. ………................................................................................................................................. (ii) [1] What property of a gas molecule affects the speed at which it diffuses? ………………...................................................................................................................... [1] (b) Explain each of the following in terms of the kinetic particle theory. (i) The rate of most reactions increases at higher temperatures. ................................................................................................................................................ ................................................................................................................................................ ................................................................................................................................................ ................................................................................................................................................ [3] (ii) A liquid has a fixed volume but takes up the shape of the container. A gas takes up the shape of the container but it does not have a fixed volume. .................................................................................................................................................. .................................................................................................................................................. .................................................................................................................................................. .................................................................................................................................................. .................................................................................................................................................. Compiled By: Hafiz Zeeshan Khan [3] IGCSE/GCE-CHEMISTRY 5. Element X can undergo the following physical changes. a) (i) Give the scientific name for each of the numbered physical changes. 1........................................................................................................................................... 2........................................................................................................................................... 3........................................................................................................................................... 4........................................................................................................................................... [4] (ii) Explain why the changes shown are physical changes. ...................................................................................................................................... ...................................................................................................................................... [1] (iii) One difference between boiling and evaporation is the rate at which the processes occur. State one other difference between boiling and evaporation. ...................................................................................................................................... ...................................................................................................................................... [1] b) Describe the separation, arrangement and motion of particles of element X in the solid state. separation........................................................................................................................... arrangement........................................................................................................................ motion................................................................................................................................. [3] 6. The graph shows how the temperature of a substance changes as it is cooled over a period of 30 minutes. The substance is a gas at the start. Compiled By: Hafiz Zeeshan Khan IGCSE/GCE-CHEMISTRY Each letter on the graph may be used once, more than once or not at all. (a) Which letter, S, T, V, W, X, Y or Z, shows when (i) the particles in the substance have the most kinetic energy, ……………............................................................................................................................ [1] (ii) the particles in the substance are furthest apart, .............................................................................................................................................. [1] (iii) the substance exists as both a gas and a liquid? ………................................................................................................................................... [1] (b) Use the graph to estimate the freezing point of the substance. ............................ °C [1] (c) Name the change of state directly from a solid to a gas. ………................................................................................................................................... [1] 7. (a) When chlorine gas, Cl2, is put into a gas jar, it spreads out to fill the gas jar. When bromine gas, Br2, is put into a gas jar, it also spreads out to fill the gas jar. The process takes longer for bromine gas than for chlorine gas. (i) What term describes the way that the gas particles spread out? ............................................................................................................................................ [1] (ii) Use data from the Periodic Table to explain why bromine gas takes longer to fill a gas jar than chlorine gas. ............................................................................................................................................. ............................................................................................................................................. ............................................................................................................................................ [2] (iii) Explain why increasing the temperature increases the rate at which the gas particles spread out. …….................................................................................................................................... ........................................................................................................................................... (b) Explain why energy has to be supplied to turn a liquid into a gas. .............................................................................................................................................. Compiled By: Hafiz Zeeshan Khan [1] IGCSE/GCE-CHEMISTRY ............................................................................................................................................. [1] (c) The diagrams represent the same number of particles of a gas in two containers, D and E, which have different volumes. The two containers are at the same temperature. In which container will the pressure be higher? Explain your answer. ................................................................................................................................................... .............................................................................................................................................. [1] Compiled By: Hafiz Zeeshan Khan
