KS3 Science Homework Pack 2 Homework 7 Classifying materials – 7: Separation methods 1 Read the sentences below: When copper sulphate is dissolved in water in a beaker, a bright blue liquid or solution is formed. If copper sulphate is added until no more will dissolve, a saturated solution is formed. Some blue crystals will remain at the bottom of the beaker. a b Choose words from the sentences above to answer the following questions. i What was the solvent used?...................................................................... (1) ii What was the solute used? ...................................................................... (1) iii What has happened to the copper sulphate? ............................................ (1) i What would you call the bright blue liquid? ............................................... (1) ii What would you call the liquid at the end of the experiment? ............................................................................................................................ (1) 2 Below are drawings of apparatus you could use to separate some mixtures. Put in the table the letter of the apparatus you would choose to do each job. A B D E Job C F , , ,, ,, Apparatus Separating vegetable oil and water Separating the colours in a blot of ink Separating some iron nails from sand Getting salt from a solution of salty water Getting water from a solution of ink Getting sand from a mixture of sand and water Pearson Publishing, Chesterton Mill, French’s Road, Cambridge CB4 3NP (6) 14 KS3 Science Homework Pack 2 3 4 Homework 7 (continued) Four methods of separating substances are shown below. By using a ruled line show which substances they can be used to separate: (4) Distillation • • Sand and salt water and collect both Filtration • • Sugar and water and collect sugar only Chromatography • • Soluble ink and water and collect both Evaporation • • Soluble coloured inks A student used chromatography to find out which colourings were used in her favourite sweets. The diagrams show some of her results: Yellow sweet Red sweet Purple sweet Green sweet Orange sweet a Give the colour of a sweet which contains only one colouring. .......................... (1) b Name two sweets which contain one of the same colouring. ............................ (1) c Fill in the results you would expect for the orange sweet. d Which liquid would be used to separate these colourings? ............................... (1) 5 The apparatus in the diagram is used to obtain pure water from impure water. a What temperature would the thermometer show? .................................................... (1) b (2) Thermometer A Impure water What is the function of the piece of apparatus labelled A? Cold water from tap Liquid C ................................................................................................................................. ............................................................................................................................ (1) c What is the name of the apparatus labelled A? .................................................. (1) d What is liquid C? ................................................................................................. (1) e Give the name of the process which purifies water in this way. ............................................................................................................................ (1) Total marks = 25 Pearson Publishing, Chesterton Mill, French’s Road, Cambridge CB4 3NP 15 KS3 Science Homework Pack 2 Homework 8 Classifying materials – 8: Metals and non-metals 1 Fill in the table below by ticking to show which properties are typical of metals and which of non-metals: Property Metal Non-metal Shiny Conducts heat well Conducts electricity well Feels cold Feels warm Brittle Dents when hit Dense Less dense Oxide is acidic Oxide is basic Oxide is solid Oxide is gas or liquid (13) 2 Here are some uses of materials. For each one, say if a named metal must be used, or a named non-metal or if either would be suitable. Explain your answer in each case. a tent pole ................................................................................................................................. ................................................................................................................................. b electrical power line ................................................................................................................................. ................................................................................................................................. c electrical cable insulation ................................................................................................................................. ................................................................................................................................. d bike frame ................................................................................................................................. ............................................................................................................................ (8) Pearson Publishing, Chesterton Mill, French’s Road, Cambridge CB4 3NP 16 KS3 Science Homework Pack 2 3 a Homework 8 (continued) Different elements have different properties, some of which are shown below: • Electrical insulator • Good thermal conductor • Poor thermal conductor • Melting point above room temperature • Good electrical conductor • Magnetic • Boiling point -153°C • Melting point 3422°C Magnesium is a metal. Give two properties of magnesium from the list above. (2) 1 ............................................................................................................................... 2 ............................................................................................................................... b Krypton is a gas used inside a light bulb. Give two properties of krypton from the list above which make it a good material to use. (2) 1 ............................................................................................................................... 2 ............................................................................................................................... c Tungsten is used to make the filament inside a light bulb. Give two properties from the list above which make it a good material to use. (2) 1 ............................................................................................................................... 2 ............................................................................................................................... 4 The table below shows some of the properties of three different substances – A, B and C. Complete the last column on the table by stating whether the substance is a metal, a non-metal or a compound: (3) Substance 5 Melting point °C Electrical conductivity Solubility in water Effect of heating in air A 113 Very poor Insoluble Burns to form one product – an acidic gas B 962 Very good Insoluble Loses its shiny surface C -182 Very poor Almost insoluble Burns to form two new substances Metal, non-metal or compound Rule a line to link the elements to show whether they are metals or non-metals and another line to show one of their properties: (5) Element Carbon Mercury Nickel Sulphur Copper • • • • • • • • • • Metal or non-metal Metal • Metal • Non-metal • Metal • Non-metal • • • • • • Property Magnetic Very good conductor of heat Brittle Shiny liquid Conductor of electricity Total marks = 35 Pearson Publishing, Chesterton Mill, French’s Road, Cambridge CB4 3NP 17