Unit c1 chemistry in our world

8,806 views
8,702 views

Published on

0 Comments
12 Likes
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total views
8,806
On SlideShare
0
From Embeds
0
Number of Embeds
1,522
Actions
Shares
0
Downloads
0
Comments
0
Likes
12
Embeds 0
No embeds

No notes for slide
  • Unsaturated ( contains at least 1 double bond) Plastics ( manufactured polymers)
  • AT pg 183 first icon. Get pupils to write on whiteboards the name of the monomer and the polymer it makes
  • Review using AT and pupils add to their notes key properties
  • Polyethene- it is the only artifical polymer. The others are natural
  • The vase is a wine bottle, the chair a wheelbarrow, the table a washing drum, the desk a kitchen worktop, the other chair a shopping trolley,
  • Orange Assessment – pupils to start this in the lesson – write a plan. And finish for homework
  • Unit c1 chemistry in our world

    1. 1. 06/11/12 Chemistry Unit C1 –Chemistry in our World EdExcel
    2. 2. 06/11/12 ElementsIf a solid, liquid or gas is made up of only one type ofatom we say it is an element. For example, consider atripod made up of iron: These atoms are ALL iron – there’s nothing else in here
    3. 3. 06/11/12 CompoundsCompounds aredifferent toelements. Theycontain differentatoms. Here aresome examples: Methane Sodium chloride (salt) Glucose
    4. 4. 06/11/12 Some simple compounds… CarbonMethane, CH4 Water, H2O dioxide, CO2 Key Hydrogen OxygenEthyne, C2H2 Sulphuric Carbon acid, H2SO4 Sulphur
    5. 5. Balancing equations 06/11/12Consider the following reaction: Sodium + water sodium hydroxide + hydrogen Na Na + O + H H H H H O This equation doesn’t balance – there are 2 hydrogen atoms on the left hand side (the “reactants” and 3 on the right hand side (the “products”)
    6. 6. Balancing equations 06/11/12We need to balance the equation: Sodium + water sodium hydroxide + hydrogen Na O H Na H H O + + O Na H H H H H Na O Now the equation is balanced, and we can write it as: 2Na(s) + 2H2O(l) 2NaOH(aq) + H2(g)
    7. 7. Some examples 06/11/12 2 Mg + O2 2 MgO Zn + 2 HCl ZnCl2 + H2 2 Fe + 3 Cl2 2 FeCl3 NaOH + HCl NaCl + H 2O CH4 + 2 O2 CO2 + 2H2O Ca + 2 H2O Ca(OH)2 + H22 2 NaOH + H2SO4 Na2SO4 + H 2O 2 3 2 4CH3OH + O2 CO2 + H 2O
    8. 8. Hazard signs to learn… 06/11/12 Acid Corrosive Toxic h iHarmful Irritant Oxidising
    9. 9. 06/11/12Topic 1 – The Earth’s Sea and Atmosphere
    10. 10. 06/11/12 The Earth’s AtmosphereFor the last 200 million years the atmosphere has remained roughly thesame – it contains 78% nitrogen, 21% oxygen, 1% noble gases and about0.03% CO2 Carbon dioxide, water vapour Oxygen Nitrogen Noble gases
    11. 11. 06/11/12 Evolution of the Earth’s Atmosphere Carbon Methane Ammonia Oxygen Nitrogen Others dioxide Present day atmosphere contains 78% nitrogen, 21% oxygen, 1% noble gases and about 0.03% CO24 Billion years 3 Billion years 2 Billion years 1 Billion years Present day
    12. 12. 06/11/12 Evolution of the Earth’s AtmosphereVolcanic activity Some of the oxygen isreleases CO2, methane, converted into ozone.ammonia and water The ozone layer blocksvapour into the out harmful ultra-violetatmosphere. The water rays which allows for thevapour condenses to development of new life.form oceans.4 Billion years 3 Billion years 2 Billion years 1 Billion years Present day Green plants evolve which take in CO2 and give out oxygen by photosynthesis, increasing the amount of oxygen in the atmosphere. Carbon from CO2 becomes locked up in sedimentary rocks as carbonates and fossil fuels and is dissolved into the sea. Methane and ammonia react with the oxygen and nitrogen is released.
    13. 13. 06/11/12 Carbon dioxide in the atmosphereThe amount of CO2 in the atmosphere is affected by 3 things: 1) Geological activity moves carbonate rocks deep into the Earth and they release ______ _______ into the atmosphere during volcanic activity. 2) Human activity - When fossil fuels are burned the carbon contained in them reacts with _____ to form CO2. Furthermore, deforestation means that less _____ are around to take in CO2. 3) Increased CO2 in the atmosphere causes a reaction between it and _______. These reactions do not remove ALL of the new CO2 so the greenhouse effect is still getting _______! Words – oxygen, seawater, carbon dioxide, worse, trees
    14. 14. 06/11/12Topic 2 – Materials from the Earth
    15. 15. What are rocks? 06/11/12Rocks are made from a combination of minerals and can behard or soft depending on how the minerals are arranged. Rocks can be found here… …and here… …and here… …and here
    16. 16. Sedimentary rocks 06/11/12Sandstone Limestone Chalk Conglomerate
    17. 17. Sedimentary rocks 06/11/12 How sedimentary rocks are formed: 1) Weathering 2) Transportation 3) Deposition 4) Burial
    18. 18. Metamorphic rocks 06/11/12 Quartzite Slate Marble (made from chalk or limestone)
    19. 19. Metamorphic rocks 06/11/12Metamorphic rocks are formed by the combined effect ofheat and pressure on other rocks: Pressure from rocks above… …and heat from magma nearby
    20. 20. Igneous rocks 06/11/12 ObsidianGranite Pumice
    21. 21. Igneous Rock 06/11/12 Granite – a slow cooling rock with big crystals and rich in silica Rhyolite – a fast cooling rock with small crystals and rich in silica Gabbro – a slow cooling rock withBasalt – a fast cooling rock with big crystals and rich in ironsmall crystals and rich in iron
    22. 22. Igneous rocks 06/11/12Igneous rocksare formedwhen lava ormagma coolsdown andsolidifies If the lava or magma cools QUICKLY it has SMALL crystals If the lava or magma cools SLOWLY it has BIG crystals
    23. 23. Summary 06/11/12Sedimentary, igneous or How they were formed Appearance metamorphic? Sedimentary Small pieces of sediment Usually soft, can contain were ______ together by ________, easily eroded salt and pressure from rocks(e.g. sandstone, _______, above chalk) Liquid rock (______ or lava) Contain ______, very hard, Igneous cooled down and turned back never contain fossils into a ______ (e.g. basalt, _______) Other rocks were acted on by Sometimes have tiny crystals, Metamorphic heat and _______ over a long no fossils, always hard and time sometimes arranged in (e.g. ______, slate) _______ Words to use – layers, stuck, granite, marble, fossils, limestone, crystals, pressure, magma, solid
    24. 24. 06/11/12 Conservation of mass in reactions In any reaction the total mass of products is the same as the total mass of the reactantsExample 1 – Magnesium oxide and hydrochloric acid H Cl Mg O Cl H Mg Cl O H H Cl1 x magnesium, 1 x oxygen, 2 x Also 1 x magnesium, 1 x oxygen, 2hydrogen and 2 x chlorine atoms x hydrogen and 2 x chlorine atomsExample 2 – Burning methane H H O O O O H H C C H O H O O H O H
    25. 25. Calcium Carbonate 06/11/12Calcium carbonate is a common chemical in the Earth and we’vealready come across it in a number of forms: Limestone Chalk Marble (made from chalk or limestone)
    26. 26. Limestone 06/11/12View video of limestone being quarried
    27. 27. Limestone 06/11/12Limestone is a __________ rock made up ofmainly calcium carbonate. It’s cheap and easy toobtain. Some uses:1) Building materials – limestone can be quarriedand cut into blocks to be used in _______.However, it is badly affected by ____ ____.2) Glass making – glass is made by mixing limestonewith _____ and soda: Limestone + sand + soda glass3) Cement making – limestone can be “roasted” in a rotary kilnto produce dry cement. It’s then mixed with sand and gravelto make _______. Words – sand, building, sedimentary, concrete, acid rain
    28. 28. 06/11/12Pros and Cons of quarrying limestoneReasons why quarrying limestone Reasons why quarrying limestone is a good idea is a bad idea
    29. 29. Limestone 06/11/12Limestone has a number of uses when it undergoes chemicalreactions. There are two reactions to know:1) Firstly, a THERMAL _________________ reaction is usedto break the calcium carbonate down into calcium ______ and_______ __________: HEAT Calcium carbonate calcium oxide + carbon dioxide2) _____ is then added to produce calcium __________: WATER Calcium oxide calcium hydroxide Words – hydroxide, decomposition, carbon dioxide, water, oxide
    30. 30. The “Limestone Cycle” 06/11/12 Calcium Carbonate CO2 (limestone) Step 4: add CO2 Step 1: heatCalcium Hydroxide solution Calcium Oxide Step 3: add Step 2: more water add a little and filter water Calcium Hydroxide
    31. 31. 06/11/12 Uses of these Calcium compoundsCalcium carbonate (limestone), calcium oxide and calciumhydroxide have a number of uses:1) Neutralising acidic soil – calcium carbonate,calcium hydroxide and calcium oxide are _______and can be used to ________ soil acidity to help______ growth.2) Removing pollutants – calciumcarbonate can be used as a “_______”to remove acidic gases from a coal-fired power station’s waste products,helping prevent ____ _____. Words – acid rain, alkaline, plant, scrubber, neutralise
    32. 32. 06/11/12 Thermal decomposition of carbonatesLimestone undergoes thermal decomposition when heated.The same happens to other carbonates. For example, considercopper carbonate: Copper carbonate (green) turns into copper oxide (black) Limewater Limewater goes cloudy due to carbon dioxide being made Copper carbonate copper oxide + carbon dioxide
    33. 33. Topic 3 – Acids 06/11/12 IndigestionLearning Objective: Be able to explain why stomachacid is produced and how antacids are used toneutralise the excess acid that causes indigestion.Starter: Write down as many facts you know aboutacids, alkalis and neutralisation.
    34. 34. Learning Outcomes
    35. 35. Neutralisation reactions 06/11/12When acids and alkalis react together they will NEUTRALISEeach other: Sodium hydroxide Hydrochloric acid Na OH H Cl The sodium replaces the hydrogen from HCl Na Cl H 2O Sodium chloride Water
    36. 36. Neutralisation experiment 06/11/12In this experiment we mixed sodium hydroxide (an _____) andhydrochloric acid together and they ________ each other.The equation for this reaction is… Sodium hydroxide + hydrochloric acid sodium chloride + waterA ____ was formed during the reaction, and we could haveseparated this by __________ the solution. The salt that weformed depended on the acid: • Hydrochloric acid will make a CHLORIDE • Nitric acid will make a _________ • Sulphuric acid will make a _________ Words – nitrate, neutralised, alkali, sulphate, salt, evaporating
    37. 37. Stomach Acid 06/11/12Hydrochloric acid is used in the stomach tohelp _______ and to kill ______. If we eattoo many “rich” foods our stomachs createtoo much ____ – this is called ______. Thisacid needs to be neutralised by takingindigestion tablets. Indigestion tabletscontain substances such as _______ thatneutralise excess stomach acid. Words – digestion, indigestion, acid, alkalis, bacteria
    38. 38. Topic 3 – Acids 06/11/12 NeutralisationLearning Objective: Be able to explain how acids areneutralisedStarter: Complete the following word equations:Hydrochloric Acid + Sodium HydroxideHydrochloric Acid + Calcium CarbonateSulphuric Acid + Aluminium Hydroxide
    39. 39. Learning Outcomes
    40. 40. Neutralisation reactions 06/11/12A neutralisation reaction occurs when an acid reacts with an alkali. Analkali is a metal oxide or metal hydroxide dissolved in water. ACID + ALKALI SALT + WATER O Cl H Na H Cl Na O H HCopy and complete the following reactions:1) Sodium hydroxide + hydrochloric acid2) Calcium hydroxide + hydrochloric acid3) Sodium hydroxide + sulphuric acid4) Magnesium hydroxide + sulphuric acid
    41. 41. Making salts 06/11/12Whenever an acid and alkali neutralise each other we are leftwith a salt, like a chloride or a sulphate. Complete thefollowing table: Hydrochloric Sulphuric acid Nitric acid acidSodium Sodiumhydroxide chloride + waterPotassium Potassiumhydroxide sulphate + waterCalcium Calciumhydroxide nitrate +
    42. 42. Using different bases 06/11/12A metal oxide base: Acid + metal oxide natural salt solution + water heatSuphuric acid + copper oxide copper sulphate + water H2SO4(aq) + CuO(s) heat CuSO4(s) + H2O(l)A metal carbonate base: Acid + metal carbonate natural salt sol n + water + CO2 heatSulphuric acid + calcium carbonate calcium sulphate + water + CO 2 H2SO4(aq) + CaCO3(s) heat CaSO4(aq) + + H20(l) + CO2(g)
    43. 43. 06/11/12 Reactions of metals carbonates with acidA metal carbonate is a compound containing a metal, carbonand oxygen. METAL CARBONATE + ACID SALT + CARBON DIOXIDE + WATER Mg O H Cl O Cl Mg O C C H H O O H Cl Cl OCopy and complete the following reactions:1) Magnesium carbonate + hydrochloric acid2) Calcium carbonate + hydrochloric acid3) Sodium carbonate + sulphuric acid
    44. 44. 06/11/12Reactions of metal oxides with acidA metal oxide is a compound containing a metal and oxide. They aresometimes called BASES. For example: O O Al O Na O Mg Na Al O Magnesium oxide Sodium oxide Aluminium oxide METAL OXIDE + ACID SALT + WATER H Cl Mg O Cl H Mg Cl O H H ClCopy and complete the following reactions:1) Magnesium oxide + hydrochloric acid2) Calcium oxide + hydrochloric acid3) Sodium oxide + sulphuric acid
    45. 45. Electrolysis of Hydrochloric Acid 06/11/12 Positiveelectrode + H+ - Negative electrode + - + Cl- -Hydrochloric + H+ - Cl- acid H+ Cl-
    46. 46. Testing for Hydrogen 06/11/12 “POP”
    47. 47. Testing for Chlorine 06/11/12Chlorine “bleaches” damp indicator paper. It is also a toxic gasso don’t breathe it! This leads to problems when it comes tolarge-scale manufacture of chlorine gas.
    48. 48. Topic 3 – Acids 06/11/12 The Importance of ChlorineLearning Objective: Be able to produce a mind map toshow how chlorine is produced, what chlorine is usedfor and the potential problems with chlorine.importance and the show what the usesStarter: Complete the true and false statementsabout chlorine.
    49. 49. Learning Outcomes
    50. 50. Electrolysis of seawater 06/11/12 Seawater is a mixture of water and salt (sodium chloride) and we can electrolyse it to produce chlorine and other useful products: Chlorine gas (Cl2) Hydrogen gas (H2)Sodiumchloridesolution(seawater)NaCl(aq) Sodium hydroxide (NaOH(aq)) Positive Negative electrode electrode
    51. 51. Uses of chlorine 06/11/12Polyvinylchloride (PVC) is made up of lots of monomers of vinylchloride (chloroethene): H Cl H Cl H H H H C C C C C C C C H H H H H H H H Chloroethene Lots more Polyvinylchloride (PVC) monomer Chloroethene monomersChlorine is also used in the manufacture of bleach.Sodium hydroxide is reacted with chlorine to formsodium hypochlorite (bleach): Cl2 + 2 NaOH → NaCl + NaClO + H2O
    52. 52. Topic 3 – Acids 06/11/12 Electrolysis of WaterLearning Objective: Be able to explain what are theproducts from the electrolysis of water and how totest for these gases.Starter: How would you test for Hydrogen, Chlorine,Carbon Dioxide and oxygen gas?? Write it down
    53. 53. Learning Outcomes
    54. 54. Electrolysis of Water 06/11/12Water is two atoms of hydrogen and one atom ofoxygen. It can be electrolysed to break it down: H O H Oxygen gas (O2) Hydrogen gas (H2) Water H 2O Positive Negative electrode electrode
    55. 55. Testing for Oxygen 06/11/12Oxygen will relight a glowing splint
    56. 56. 06/11/12Topic 4 – Obtaining and Using Metals OresLearning Objective: Be able to explain how metals areextracted using the reactivity seriesStarter: What is the reactivity series??
    57. 57. Learning Outcomes
    58. 58. Reactivity series demonstration • All metal elements have a different reactivity. • Some such as sodium are very reactive even in air. • Others such as gold are extremely unreactive. • Watch the demonstration and think about which elements are more reactive.
    59. 59. Finding an order?• Can you place these elements a list of reactivity with most reactive a the top and least at the bottom? Sodium Sodium Copper Copper Zinc Zinc Magnesiu Magnesiu m m Gold Gold Iron Iron
    60. 60. Extracting Metals 06/11/12Some definitions:A METAL ORE is a mineral or mixture ofminerals from which it is “economicallyviable” to extract some metal.Most ores contain METAL OXIDES (e.g. rust = iron oxide).To “extract” a metal from a metal oxide we need to REDUCEthe oxygen. This is called a REDUCTION reaction. To put itsimply: Iron “Reduce” the oxygen Iron Oxide ore to make iron
    61. 61. How do we do it? 06/11/12Potassium Metals ABOVE CARBON, because Sodium of their high reactivity, are extracted by ELECTROLYSIS, Calcium which is very expensive!Magnesium Metals BELOW CARBON areAluminium extracted by heating them with Carbon carbon in a BLAST FURNACE. This is a “displacement reaction” Zinc Iron Tin Carbon Iron Oxide Lead Copper These LOW REACTIVITY metals won’t Silver need to be extracted because they are Gold SO unreactive you’ll find them on their own, not in a metal oxide Platinum
    62. 62. Extracting metals• A metal can be extracted from a compound by reacting with an element higher up in the reactivity series.• So for example copper is more reactive than silver.• If we add copper metal to silver nitrate compound we make silver metal.• Draw a picture of this in your book.
    63. 63. Extracting iron• Iron ore (haematite) is iron oxide.• To make iron we need to remove the oxygen.• This process is called REDUCTIONCopy down this equationIron oxide + carbon  Iron + CarbonIron oxide + carbon  Iron + Carbon dioxide dioxide
    64. 64. Extracting Iron from its ore• Carbon can also be put into the reactivity series and is higher (more reactive) than iron.• This means iron can be extracted from its ore using carbon.
    65. 65. Notes to copy and completeMetals that are ______ reactive than carbon in the reactivity series can be ___________ from their oxides by _________ with ________.Iron oxide is reduced in the _________ ________ to make iron.[extracted, reduction, carbon, less, blast furnace]
    66. 66. What are Ores?Most metals are too …………… to exist on their own in the ground.Instead they exist combined with other elements (typically o………..or sulphur) as ……………….. called ………….A few metals are so ……………….. that they exist uncombined, as……….metals e.g. gold, ……………….. Metal Name of ore Compound in ore Words: Aluminium Bauxite Aluminium oxide (Al2O3) ores silver reactive oxygen compounds unreactive pure
    67. 67. Displacement Reactions1. Iron + Copper Sulphate  Iron Sulphate + Copper2. Copper + Silver Nitrate  Copper Nitrate + Silver3. Sodium + Zinc Carbonate  Sodium Carbonate + Zinc4. Potassium + Iron Oxide  Potassium Oxide + Iron5. Gold + Copper Carbonate  Gold + Copper Carbonate No reaction! Can you figure out why?
    68. 68. How do we extract metals from ores?Watch this video clip:http://jchemed.chem.wisc.edu/JCESoft/CCA/samples/cca7thermIt is called the thermite reaction.The symbol equation is: Fe2O3 + Al  Al2O3 + Fe1. Copy out the symbol equation and write the word equation underneath.2. Why does this reaction happen?3. Do you think that it’s a commercially viable way of extracting iron from its ore? Explain your answer.
    69. 69. So how is it done?PotassiumSodiumMagnesium The reactivity series of metals…AluminiumZinc Carbon can be used to extract some metals fromIron their ores e.g.Copper Copper oxide + Carbon  Copper + Carbon dioxideSilver The copper oxide has lost oxygen. This is called aGold reduction reaction.
    70. 70. Potassium Extracted from their ores bySodium electrolysis (using electricity)AluminiumCarbonZinc Extracted from their ores byIron reduction by carbonCopperSilver No extraction necessary – foundGold pure in the ground.
    71. 71. Extracting metals 06/11/121) What is an ore?2) In what form are metals usually found in the Earth?3) How do you get a metal out of a metal oxide?4) What is this type of reaction called? Type of metal Extraction process Examples High reactivity (i.e anything above carbon) Middle reactivity (i.e. anything below carbon) Low reactivity
    72. 72. 06/11/12 Extracting AluminiumAluminium has to be extracted from its ore by electrolysis. This isbecause aluminium is very ___________ and so it cannot be extractedusing ______. The amount of energy and _____ required to extractaluminium and other metals is very high and so ________ is a muchbetter option. Words – reactive, recycling, money, carbon
    73. 73. Copper, Aluminium and Titanium 06/11/12 Metal Uses and why Extraction Problems method Copper Electrical wires – Electrolysis Limited supply good conductor Gold Jewellery – None needed – Limited supply attractive and its unreactive so and very resistant to you find it in the expensive corrosion Earth as goldAluminium and Planes – light and Complicated and Expensive and titanium corrosion expensive difficult to resistant extract
    74. 74. 06/11/12Topic 4 – Obtaining and Using Metals Oxidation and ReductionLearning Objective: Be able to explain the termsoxidation and reduction and relate it to equationsStarter: If reduction means removingthe oxygen what do you think oxidationmeans??
    75. 75. 06/11/12
    76. 76. Learning Outcomes
    77. 77. Rusting 06/11/12Rust is a hydrated form ofiron oxide. It is formedwhen iron and/or steelcombines with oxygen andwater in an oxidationreaction: Iron + oxygen + water hydrated iron (III) oxide
    78. 78. Rusting 06/11/12Task: To investigate what causes rusting Tube 1 – Tube 2 – Tube 3 – Tube 4 – drying boiled water + air water + air agent water + salt
    79. 79. Rusting 06/11/12Task: To investigate what causes rusting No rust No rust Rust Lots of rust Iron + oxygen + water hydrated iron oxide
    80. 80. Reducation and Oxidation 06/11/12Some examples of reduction: heat Aluminium + iron oxide aluminium oxide + iron 2Al(s) + Fe2O3(s) heat Al2O3(s) + 2Fe(s) heat Lead oxide + carbon lead + carbon dioxide 2PbO(s) + C(s) heat 2Pb(s) + CO2(s)An example of oxidation: heat Magnesium + oxygen magnesium oxide Mg(s) + O2(s) heat 2MgO(s)
    81. 81. More on Redox Reactions 06/11/12Basically, during a redox reaction electrons are either lost orgained: The Golden Rule: OILRIG Oxidation Is Loss (of electrons) Reduction Is Gain (of electrons)For example:Fe Fe2+ These reactions both involve the loss of2Cl- Cl2 electrons – they are Oxidation reactionsFe2+ Fe These reactions both involve the gain of electrons – they are Reduction reactionsCl2 2Cl-
    82. 82. C1.18 Reactions .Is the substance in red being oxidised orreduced in the following reaction?magnesium + oxygen → magnesium oxideOxidised
    83. 83. C1.18 Reactions .Is the substance in red being oxidised orreduced in the following reaction?lead oxide + carbon → lead + carbon dioxideReduced
    84. 84. C1.18 ReactionsIs the substance in red being oxidised orreduced in the following reaction?magnesium + hydrogen → magnesium + water oxideReduced
    85. 85. C1.18 ReactionsIs the substance in red being oxidised orreduced in the following reaction?nickel + oxygen → nickel oxideOxidised
    86. 86. C1.18 ReactionsIs the substance in red being oxidised orreduced in the following reaction?4 Na + O2 → 2 Na2OOxidised
    87. 87. C1.18 ReactionsIs the substance in red being oxidised orreduced in the following reaction?Cr2O3 + 2 Al → 2 Cr + Al2O3Reduced
    88. 88. 06/11/12Topic 4 – Obtaining and Using Metals Recycling MetalsLearning Objective: Be able to explain the importanceof recyclingStarter: Explain how recycled is carried out inNewham
    89. 89. Learning Outcomes
    90. 90. Recycling 06/11/12 Why recycle metals?1) Less space will be needed for landfill sites2) Recycled metals only need about 1/10th of the energy to produce compared to producing new metals3) Recycling saves on raw materials4) Less excavation and mining costs
    91. 91. 06/11/12 Topic 4 – Obtaining and using metals Properties of metals and AlloysLearning Objective: Explain why certain metals areused in relation to their properties.Describe ways metal properties can be improved.Starter: Sort out he properties of the metals on theworksheet.
    92. 92. Learning Outcomes
    93. 93. C1.20 Why use that metal? Why are electrical cables made from copper?© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is notcopyright free. This document may have been altered from the original.
    94. 94. C1.20 Why use that metal? Why are aeroplanes made with a lot of aluminium?© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is notcopyright free. This document may have been altered from the original.
    95. 95. C1.20 Why use that metal? Why is jewellery made from gold?© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is notcopyright free. This document may have been altered from the original.
    96. 96. C1.20 Why use that metal? Why are cars made from steel?© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is notcopyright free. This document may have been altered from the original.
    97. 97. C1.20 Why use that metal? Why are cooking pans made from aluminium?© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is notcopyright free. This document may have been altered from the original.
    98. 98. C1.20 Why use that metal? Why is gold used on audio cables?© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is notcopyright free. This document may have been altered from the original.
    99. 99. C1.20 Why use that metal? Why are hot water pipes made from copper?© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is notcopyright free. This document may have been altered from the original.
    100. 100. C1.20 Why use that metal? Why are bridges made from steel?© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is notcopyright free. This document may have been altered from the original.
    101. 101. C1.20 Why use that metal? Why is aluminium used in heat sinks for microprocessors?© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is notcopyright free. This document may have been altered from the original.
    102. 102. © Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is notcopyright free. This document may have been altered from the original.
    103. 103. 06/11/12Using impurities to strengthen IronIn pure iron allimpurities areremoved. Thismakes the iron soft:Adding 1% impuritiesmakes the iron muchstronger:
    104. 104. Alloys 06/11/12Steel is an “alloy” – i.e. a mixture of metals. Here are otheralloys:Gold mixed with Aluminium mixed Aluminiun mixedcopper with magnesium with chromium and copper
    105. 105. 06/11/12 Making steel Strong Strength Hardness Amount of Weak carbon 0.5% 1% 1.5% added (%)Steel with a low Steel with a high Steel with chromiumcarbon content is carbon content is and nickel is calledeasily shaped strong but brittle stainless steel
    106. 106. Smart Alloys 06/11/12A “smart alloy” is one that can “remember” its original stateafter being bent or stretched.These glasses are made from a “smart” material – if they arebent they will return to their original shape. They could bemade from an alloy called “nitinol” (an alloy of nickel andtitanium) which can be bent but then returned to its originalshape simply by heating to its “transformation temperature”.
    107. 107. Gold alloys 06/11/12Gold can be mixed with other metals to make alloys withdifferent properties. For example: 24-Carat gold 9-Carat gold“Pure gold” – 99.99% of the atoms “9 carat gold” – around 9/24thsin this bar are gold atoms (fineness of the atoms in these earringsoff 999.9). Pure and malleable but are gold atoms. Harder thansoft. pure gold but less malleable.
    108. 108. Materials in a Car 06/11/12 Copper wires Glass Nylon windscreen seatbeltsPlastic trim Steel body Alloy wheels
    109. 109. Iron or aluminium? 06/11/12Aluminium:Does not corrodeLess dense so it’s lighterIron:Cheaper than aluminiumMagnetic so easily recycled Most cars are made from steel (an alloy of carbon)From 2015 95% of a car will have to be made from recycledmaterial. What are the advantages of this?
    110. 110. 06/11/12 Topic 5 – Fuels Crude OilLearning Objective: Explain how crude oil is formedand its uses.Starter: What elements are contained inHydrocarbons
    111. 111. Learning Outcomes
    112. 112. Fuels 06/11/12Fuels are substances that can be used to release usefulamounts of energy when they burn, e.g. Wood Oil Gas Coal These fuels are called “fossil fuels” and are described as being “non-renewable”.
    113. 113. Crude Oil 06/11/12
    114. 114. 06/11/12 Topic 5 – Fuels Crude Oil fractions Learning Objective:Explain how hydrocarbon fractions are separated.Starter: Write down three facts you remember formlast lesson
    115. 115. Learning Outcomes
    116. 116. 06/11/12 Hydrocarbons and crude oil Crude oil is a mixture of HYDROCARBONS (compounds made up of carbon and hydrogen). Some examples: H H Longer chains mean… Increasing length H C C H H H 1. Less ability to flow Ethane 2. Less flammable H H H HH C C C C H 3. Less volatile H H H H 4. Higher boiling point Butane
    117. 117. Distillation revision 06/11/12 This apparatus can be used to separate water and ink because they have different _____ ______. The ______ will evaporate first, turn back into a _______ in the condenser and collect in the _______. The ink remains in the round flask, as long as the _______ does not exceed ink’s boiling point. This method can be used to separate crude oil.Words – temperature, boiling points, water, beaker, liquid
    118. 118. . 06/11/12Sort them into benefits and drawbacks of using oil1 Accidents with oil wells or oil tankers can pollute the sea andkill wildlife.2 Cars that run on petrol are much more convenient thanbattery-powered cars.3 Burning fossil fuels produces carbon dioxide and otherpolluting gases.4 We can make lots of different chemicals out of thesubstances in crude oil.5 Crude oil will run out one day.6 Bitumen is very useful for making roads.7 We need oil to lubricate engines and other moving machines.8 Petrol can cause explosions if it is not transported and stored correctly.
    119. 119. Fractional distillation 06/11/12Crude oil can be separated by fractional distillation. The oil is evaporatedand the hydrocarbon chains of different lengths condense at differenttemperatures:Fractions withlow boilingpoints condenseat the topFractions withhigh boilingpoints condenseat the bottom
    120. 120. 9Hb How fractional distillation works C1.23 Fractional distillation How fractional distillation works© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not copyright free.
    121. 121. 9Hb How fractional distillation works C1.23 Fractional distillation Crude oil is a mixture of different hydrocarbon molecules. The molecules have different numbers of carbon and hydrogen atoms in them. Some of the different molecules in crude oil.© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not copyright free.
    122. 122. 9Hb How fractional distillation works C1.23 Fractional distillation Molecules of different sizes have to be separated before oil can be used. This is done in an oil refinery. The process of separating crude oil is called fractional distillation. The different mixtures produced An oil refinery. The tall towers are are called fractions. fractionating columns.© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not copyright free.
    123. 123. 9Hb How fractional distillation works C1.23 Fractional distillation Fractional distillation works because the different molecules in crude oil have different boiling points. There are tiny forces of attraction between all molecules. The longer the molecule, the bigger this force. So long molecules tend to stick together more than small ones. The bigger the force, the more energy is needed to allow the molecules to break away from the liquid and form a gas. So longer molecules have higher boiling points.© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not copyright free.
    124. 124. 9Hb How fractional distillation works C1.23 Fractional distillation gases The diagram shows a fractionating column. It is hotter at the petrol bottom than at the column top. getting cooler kerosene diesel oil Click on a number to find out more. fuel oil bitumen© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not copyright free.
    125. 125. 9Hb How fractional distillation works C1.23 Fractional distillation gases 1 Crude oil is heated petrol until it boils. The gas column is fed into the bottom getting cooler of the fractionating kerosene column. diesel oil fuel oil bitumen Back to fractionating column© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not copyright free.
    126. 126. 9Hb How fractional distillation works C1.23 Fractional distillation gases 2 The hot crude oil vapour goes petrol into the fractionating column. column getting It starts to cool down. Fuel oil, cooler kerosene waxes and bitumen condense and run out of the pipe at the diesel oil bottom. These fractions have the fuel oil longest molecules and the highest boiling points. bitumen Back to fractionating column© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not copyright free.
    127. 127. 9Hb How fractional distillation works C1.23 Fractional distillation gases 3 The rest of the crude oil petrol gas rises up the column. column It cools as it rises. getting cooler kerosene The largest molecules left in the gas condense next. diesel oil They fall onto the tray. fuel oil bitumen Back to fractionating column© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not copyright free.
    128. 128. 9Hb How fractional distillation works C1.23 Fractional distillation gases 4 The next longest molecules petrol condense here. column Each set of trays collects getting cooler kerosene condensed molecules with carbon numbers in a diesel oil particular range. fuel oil bitumen Back to fractionating column© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not copyright free.
    129. 129. 9Hb How fractional distillation works C1.23 Fractional distillation gases 5 The condensed liquids petrol are removed through pipes. Some of them go column getting to further fractionating cooler kerosene columns to separate them further. diesel oil fuel oil bitumen Back to fractionating column© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not copyright free.
    130. 130. 9Hb How fractional distillation works C1.23 Fractional distillation gases 6 The smallest molecules petrol in crude oil are gases at normal temperatures. column getting cooler kerosene These gases are removed from the top of diesel oil the column. fuel oil bitumen Back to fractionating column© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not copyright free.
    131. 131. 06/11/12 Match up the names and usesFractions Gases Fuel oil Kerosene Petrol Bitumen Diesel oilUses Fuel for some cars Fuel for some cars Making roads Cooking in homes Fuel for large ships Fuel for aircraft Heating homes Fuel for some trains Fuel for some powerMaking roofs waterproof stations
    132. 132. 06/11/12
    133. 133. 06/11/12 Topic 5 – Fuels Combustion Learning Objective:•Able to explain what is produced when hydrocarbonsburn.Starter: Draw a brainstorm to show everything youremember about crude oil.
    134. 134. Learning Outcomes
    135. 135. Burning Hydrocarbons 06/11/12Burning hydrocarbons will produce water, carbon dioxide andenergy: H H O O O O H H C C H O H O O H O H Methane + Oxygen Carbon + Water dioxideIn this reaction the hydrocarbon is oxidised.
    136. 136. Testing for Carbon Dioxide 06/11/12 Gas Limewater Limewater turns milky/cloudy
    137. 137. Burning Hydrocarbons 06/11/12 H H O O O HLots of C O C Hoxygen: H O H O O H O H Methane + Oxygen Carbon + Water dioxide H O H H O H O O C O H C H HSome H O Ooxygen: H H C O H O H C O O O H H H H Methane + Oxygen Carbon + Water monoxide H O H H HLittle C O C O Ooxygen: H H H H Methane + Oxygen Carbon + Water
    138. 138. C1.24 Balancing equations We can represent what happens in chemical reactions using symbol equations. We use a symbol (of one or two letters) to represent atoms of different elements. We also use symbols to show how many atoms of different kinds are joined together to make a compound.© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not copyright free.
    139. 139. C1.24 Balancing equations For example: Hydrogen chloride molecules are made from one atom of hydrogen joined to one atom of chlorine. HCl H Cl Water molecules are made from one atom of oxygen joined to two atoms of hydrogen. The little 2 shows there are two hydrogen atoms. H2O H O H© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not copyright free.
    140. 140. C1.24 Balancing equations Hydrogen gas reacts with chlorine gas to form hydrogen chloride. Hydrogen and chlorine gases both exist as pairs of atoms. H Cl H + H Cl Cl H2(g) + Cl2(g) HCl(g)© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not copyright free.
    141. 141. C1.24 Balancing equations But this isnt quite right yet – the reactants have two atoms of hydrogen and two of chlorine. Atoms are not created or destroyed in a reaction, so we must have two hydrogen atoms and two chlorine atoms in the products. H Cl H Cl H + Cl H Cl H2(g) + Cl2(g) 2HCl(g)© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not copyright free.
    142. 142. C1.24 Balancing equations The 2 in front of the HCl in the symbol equation shows that there are two complete molecules of hydrogen chloride. H Cl H Cl H + Cl H Cl H2(g) + Cl2(g) 2HCl(g)© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not copyright free.
    143. 143. C1.24 Balancing equations Hydrogen and oxygen react to form water. H O O H + H H O H2(g) + O2(g) H2O(g)© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not copyright free.
    144. 144. C1.24 Balancing equations There are more oxygen atoms in the reactants than the products, so we must have made more than one molecule of water. H O H O O H + H H H O H2(g) + O2(g) 2H2O(g)© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not copyright free.
    145. 145. C1.24 Balancing equations But now there are more hydrogen atoms in the products than in the reactants. We must have started with more than one hydrogen molecule. H O H H O H O H + H H H O 2H2(g) + O2(g) 2H2O(g)© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not copyright free.
    146. 146. C1.24 Balancing equations This is now a balanced symbol equation to show the reaction of hydrogen and oxygen to form water. H O H H O H O H + H H H O 2H2(g) + O2(g) 2H2O(g)© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not copyright free.
    147. 147. C1.24 Balancing equations Try these examples. Click on an example to see how to work out the balanced symbol equation. Methane (CH4) reacts with oxygen to form carbon dioxide and water. Magnesium reacts with oxygen to form magnesium oxide (MgO).© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not copyright free.
    148. 148. C1.24 Balancing equations Methane (CH4) reacts with oxygen to form carbon dioxide and water. O H O C H O H C H + + O H H O CH4(g) + O2(g) CO2 + H2O(g)© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not copyright free.
    149. 149. C1.24 Balancing equations There are more oxygen atoms in the products than the reactants, so we must have started with more oxygen. O O H O C H O H C H + + O H H O O CH4(g) + 2O2(g) CO2 + H2O(g)© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not copyright free.
    150. 150. C1.24 Balancing equations Now there are more oxygen atoms in the reactants than the products. The reaction must produce more water molecules. O O H O H O C H H C H + + O H O H O O H CH4(g) + 2O2(g) CO2 + 2H2O(g)© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not copyright free.
    151. 151. C1.24 Balancing equations The equation is balanced. You can check this by counting up the numbers of atoms on each side of the equation. O O H O H O C H H C H + + O H O H O O H CH4(g) + 2O2(g) CO2 + 2H2O(g)© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not copyright free.
    152. 152. C1.24 Balancing equations Magnesium reacts with oxygen to form magnesium oxide (MgO). Mg O Mg + O O Mg(s) + O2(g) MgO(s)© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not copyright free.
    153. 153. C1.24 Balancing equations There are more oxygen atoms in the reactants than the products, so the reaction must produce more magnesium oxide. Mg O Mg O + O Mg O Mg(s) + O2(g) 2MgO(s)© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not copyright free.
    154. 154. C1.24 Balancing equations And we must have started with more than one magnesium atom… Mg O Mg O Mg + O Mg O 2Mg(s) + O2(g) 2MgO(s)© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not copyright free.
    155. 155. C1.24 Balancing equations Now the symbol equation is balanced. Mg O Mg O Mg + O Mg O 2Mg(s) + O2(g) 2MgO(s)© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not copyright free.
    156. 156. C1.24 Questions and answers1 Give an example of a hydrocarbon fuel.A: Any named hydrocarbon that can be used as a fuel – petrol, diesel, kerosene etc.2 Why is combustion an example of an oxidation reaction?A: The reaction combines a fuel with oxygen.© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not 156copyright free. This document may have been altered from the original.
    157. 157. C1.24 Questions and answers 3 Look at Figure B. What is the source of oxygen that allows the candle to burn? A: Air© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not 157copyright free. This document may have been altered from the original.
    158. 158. C1.24 Questions and answers 4 In Figure B, which part of the apparatus shows that: a carbon dioxide is produced A: Limewater b oxygen is produced? A: Copper sulfate© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not 158copyright free. This document may have been altered from the original.
    159. 159. C1.24 Questions and answers 5 Butane is a hydrocarbon compound found in crude oil. Write a word equation for the combustion of butane. A: Butane + oxygen → carbon dioxide + water© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not 159copyright free. This document may have been altered from the original.
    160. 160. C1.24 Questions and answers 6 Limewater is calcium hydroxide solution, Ca(OH)2. It forms calcium carbonate,CaCO3, and water when it reacts with carbon dioxide. a Write a word equation for this reaction. A: Calcium hydroxide solution + carbon dioxide → calcium carbonate + water© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not 160copyright free. This document may have been altered from the original.
    161. 161. C1.24 Questions and answers b Why does limewater go milky when carbon dioxide is bubbled through it? A: The calcium carbonate formed is a solid; the cloudiness is due to tiny particles of solid calcium carbonate (a precipitate) in the water. c Write a balanced equation for the reaction. A: Ca(OH)2(aq) + CO2(g) → CaCO3(s) + H2O(l)© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not 161copyright free. This document may have been altered from the original.
    162. 162. C1.24 Questions and answers 7 Jose says, ’Burning petrol produces nitrogen oxides and water’. Explain how you can tell he is wrong just by using the fact that petrol is a mixture of hydrocarbon molecules. A: Answers may include: Petrol compounds are hydrocarbons so they only contain carbon and hydrogen atoms; burning uses only oxygen from the air; neither of the reactants contain nitrogen, so a compound contains nitrogen cannot be one of the products of the reaction.© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not 162copyright free. This document may have been altered from the original.
    163. 163. 06/11/12 Topic 5 – Fuels Incomplete combustion and Acid Rain Learning Objective: Explain what happens if there is not enough oxygen for burning. Explain the consequences of Acid RainStarter: Write a balanced equation to showcombustion.
    164. 164. Learning Outcomes
    165. 165. Incomplete Combustion 06/11/12As well as producing carbon monoxide, incomplete combustioncan also produce soot: H O H H HLittle C O C O Ooxygen: H H H H Methane + Oxygen Carbon + Water “Soot”
    166. 166. 06/11/12Why Carbon Monoxide is DangerousBasically, carbon monoxide “sticks” to red blood cells insteadof oxygen, causing anybody inhaling it to essentially suffocate: CO 1) Carbon Monoxide is breathed in 2) The molecule “sticks” to red blood cells instead of oxygen 3) The red blood cells transport the “carboxyhaemoglobin” molecule to the rest of the body and the body’s cells are starved of the oxygen needed for respiration. Carbon monoxide is odourless, colourless and non-irritating so it’s very difficult to detect!
    167. 167. Burning Fossil Fuels 06/11/12 Burning fossil fuels like oil and coal causes pollution.Oil contains carbon: H H O O O O H H C C H O H O O H O H Carbon dioxide is a “greenhouse gas” – it helps cause global warmingCoal contains carbon, sulfur and other particles: sulfur + oxygen sulfur dioxide Sulfur dioxide causes acid rain. Other particles can cause “global dimming” – sunlight is absorbed by the particles in the atmosphere.
    168. 168. 06/11/12
    169. 169. C1.26 Questions and answers1 Why is rain normally slightly acidic?A: Contains dissolved carbon dioxide from the air.© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not 169copyright free. This document may have been altered from the original.
    170. 170. C1.26 Questions and answers 2 A What is ‘acid rain’? A: Rain that is more acidic than normal. b What causes acid rain? A: Acidic gases such as sulfur dioxide and nitrogen oxides dissolved in rainwater.© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not 170copyright free. This document may have been altered from the original.
    171. 171. C1.26 Questions and answers3 What effect does acid rain have on: a the water in rivers and lakesA: Makes it more acidic (lowers pH). b organisms that live in rivers and lakesA: Can harm or kill them. c treesA: Damages them and can kill them. d stone buildings and statues?A: Weathers the stone by chemical reactions, so it breaks up and erodes faster.© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not 171copyright free. This document may have been altered from the original.
    172. 172. C1.26 Questions and answers 4 Limestone (calcium carbonate) can be used to neutralise the sulfuric acid that makes lakes acidic. Write a word equation for this neutralisation reaction. A: Calcium carbonate + sulfuric acid → calcium sulfate + water + carbon dioxide© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not 172copyright free. This document may have been altered from the original.
    173. 173. C1.26 Questions and answers 5 Describe how acid rain forms and describe two ways in which acid rain in Europe has been reduced. A: Answers may include: Sulfur compounds in burning fossil fuels form sulfur dioxide, which dissolves in rain to form an acidic solution; sulfur impurities can be removed from fuels before they are sold and burnt; for fuels used in power stations, an alternative is to remove the sulfur dioxide from the waste gases in the chimney, after the fuel is burnt – this is done by neutralising the acidic sulfur dioxide gas with calcium carbonate.© Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not 173copyright free. This document may have been altered from the original.
    174. 174. 06/11/12 Topic 5 – Fuels Climate change Learning Objective:Explain how human activity affects the earths temperature.
    175. 175. Learning Outcomes
    176. 176. Global Warming 06/11/12 Facts: 1) The 10 warmest years of the last century have all occurred within the last 15 years 2) Sea level has risen by between 12 and 24cm in the last 100 years 3) Rainfall has risen by 1%
    177. 177. The Greenhouse Effect 06/11/12We get heat A lot of this heat isfrom the sun: _______ back into space. However, most of it is kept inside the Earth by a layer of gases that prevent the heat escaping by _______ and then re-radiating it back again.This is called the _________ Effect. It has always been around, but is currently being made worse due to:1) Burning (releasing CO2)2) __________ (removing trees that remove CO2)3) Increased micro organism activity (from rotting ______)4) Cattle and rice fields (they both produce _______)These changes will cause GLOBAL WARMING and RISING SEA LEVELS Words – methane, radiated, absorbing, deforestation, waste, greenhouse
    178. 178. 06/11/12Carbon Dioxide and Global Warming Global levels of Carbon Dioxide in PPM Is there a link?
    179. 179. 06/11/12Reducing the amount of Carbon DioxideScientists are trying to reduce the amount of carbondioxide in the atmosphere through a number ofpossibilities:1) “Iron seeding” – this is the process where iron isintentionally put in seawater to help produce morephytoplankton which then increases photosyntheticactivity, therefore reducing the amount of CO2 in theatmosphere. Aerial view of phytoplankton near Argentina 2) Converting CO2 into hydrocarbons – carbon dioxide can be converted into hydrocarbons and then stored in the Earth by putting it in such places as old oil fields or coal beds.
    180. 180. Reducing Pollution from vehicles 06/11/12A number of suggestions:1) Buy a new, smaller, cleaner car2) Buy a “hybrid” car3) Convert your car to run on biodiesel4) Make sure your car has a catalytic converter: Carbon monoxide + oxygen carbon dioxide Nitrogen monoxide + carbon monoxide nitrogen + carbon monoxide5) Use the train or a bus!
    181. 181. 06/11/12 Topic 5 – Fuels Biofuels and choosing fuels Learning Objective: •Explain the advantages and disadvantages of using biofuels •Explain how to choose the best fuel.Starter: What do you know about biofuels
    182. 182. Learning Outcomes
    183. 183. Ethanol as a biofuel 06/11/12Ethanol is an important chemical. Manycountries are increasing the amount ofethanol put into their petrol supplies: Ford Escape E85 – runs on 85% ethanolEthanol is a “clean burning” energy source and produces littleor no greenhouse gases. How is it made? The “renewable” way Sugar is produced from standard crops likeSugar ethanol + carbon dioxide sugar cane and cornWhat’s the point?When ethanol burns it only produces small amounts of carbondioxide. Making more cars run on ethanol means having lesscars that need petrol.
    184. 184. C1.28 Photosynthesis and biofuelsA fuel is carbon neutral when the amount of carbon dioxideabsorbed in making the fuel equals the amount of carbon dioxideproduced when it is burned.Are biofuels carbon neutral? © Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not copyright free. This document may have been altered from the original.
    185. 185. C1.28 Photosynthesis and biofuelsPlants use carbon dioxide from the air in photosynthesis. Thematerial in a plant stores carbon atoms that have been taken outof the atmosphere. carbon dioxide © Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not copyright free. This document may have been altered from the original.
    186. 186. C1.28 Photosynthesis and biofuelsPlants can be harvested to be turned into fuel. © Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not copyright free. This document may have been altered from the original.
    187. 187. C1.28 Photosynthesis and biofuelsPlants must be converted to biofuels such as biodiesel beforethey can be used as fuel for vehicles. This is done in a refinery. © Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not copyright free. This document may have been altered from the original.
    188. 188. C1.28 Photosynthesis and biofuelsThe biofuel contains carbon that was originally taken out of theatmosphere by the plants used to make the fuel. © Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not copyright free. This document may have been altered from the original.
    189. 189. C1.28 Photosynthesis and biofuelsWhen the biofuel is burned in engines, carbon dioxide is put intothe atmosphere. carbon dioxide © Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not copyright free. This document may have been altered from the original.
    190. 190. C1.28 Photosynthesis and biofuelsBut this carbon dioxide has only recently been taken out of theatmosphere by the plants used to make the fuel. Overall, nocarbon dioxide has been added to the atmosphere.Or has it? © Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not copyright free. This document may have been altered from the original.
    191. 191. C1.28 Photosynthesis and biofuelsThe machinery used to plant the crops and harvest themneeded fuel.Fuel was needed to make fertilisers to help the crops to grow.The refinery used energy to convert the plants to biofuel.Unless all theseprocesses alsoused biofuels, thenthe biofuel is notreally carbonneutral. © Pearson Education Ltd 2011. Copying permitted for purchasing institution only. This material is not copyright free. This document may have been altered from the original.
    192. 192. Choosing a biofuel 06/11/12Does it create How much energy pollution? does it release? Biofuels Is it toxic?How much does it cost? How much land is Does it take more CO2 needed? to tranport it than it takes in from the How easy is it to atmosphere while grow/make? growing?
    193. 193. Choosing a fuel 06/11/12How easily does How much energy it burn? does it release? Which fuel should Is it toxic? you use?How much smokedoes it produce? Is it easy to use, store and transport?
    194. 194. Hydrogen Fuel Cells 06/11/12Basically, a hydrogen fuel cell combines hydrogen and oxygento form water and release energy:
    195. 195. Hydrogen Fuel Cells 06/11/12Advantages of fuel cells Advantages of petrol Hydrogen fuel cells vs Petrol
    196. 196. Energy from fuels 06/11/12 Coppercalorimeter Water Spirit burner Fuel

    ×