New Topic Fuels and Climate Chemistry. Think what is the connection between a leaf and coal?

Transcription

1 New Topic Fuels and Climate Chemistry Think what is the connection between a leaf and coal?

2 S3 Chemistry Fuels and Climate Chemistry Lesson 1 REVISION By investigating renewable energy sources and taking part in practical activities to harness them, I can discuss their benefits and potential problems SCN 3-04b NEW LEARNING Through investigation, I can explain the formation and use of fossil fuels and contribute to discussions on the responsible use of finite resources SCN 4-04b

3 Starter Questions 1. Name 3 different forms of renewable energy Wind, solar, wave, 2. What are the advantages and disadvantages of using this energy? Advantages it is sustainable. Disadvantages expensive to set up and maintain.

4 Lesson 1 - Fossil Fuels Today we will learn to Name the 3 main types of fossil fuels and explain how they are formed We will do this by Hearing about fossil fuels and watching videos and animations on their formation We will have succeeded if

5 Fossil Fuels Coal Oil Gas

6 Coal formation

7 How was coal formed? is formed over millions of years from the remains of and. They have slowly been. The and from the earth has produced. Formation of Coal Animation

8 How was coal formed? Coal is formed over millions of years from the decaying remains of plants and trees. They have slowly been buried. The heat and pressure from the earth has produced coal. Formation of Coal Animation

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10 Formation of oil & natural gas

11 How are crude oil & natural gas formed? Crude oil and natural gas are formed from decaying bodies of tiny organisms and plants over of years. They have slowly been. The and from the earth has produced oil and gas. Formation of oil and natural gas

12 How are crude oil & natural gas formed? Crude oil and natural gas are formed from decaying bodies of tiny sea organisms and plants over millions of years. They have slowly been buried. The heat and pressure from the earth has produced oil and gas. Formation of oil and natural gas

13 Card Sort Work in pairs. Sort the cards into the correct order. Once you have the cards in the correct order, number the boxes in your booklet - 1 for the first stage to 8 for the last stage for each fuel.

14 Fossil fuels summary

15 Lesson 1 - Fossil Fuels Today we will learn to Name the 3 main types of fossil fuels and explain how they are formed We will do this by Hearing about fossil fuels and watching videos and animations on their formation We will have succeeded if

16 S3 Chemistry Fuels and Climate Chemistry Lesson 2 REVISION By investigating renewable energy sources and taking part in practical activities to harness them, I can discuss their benefits and potential problems SCN 3-04b NEW LEARNING Through investigation, I can explain the formation and use of fossil fuels and contribute to discussions on the responsible use of finite resources SCN 4-04b

17 Starter Questions 1. Name the three types of fossil fuel Coal, oil and gas 2. How are they formed? (Give details!) Coal - formed over millions of years from plants and trees. They have slowly been buried and the heat and pressure from the earth has produced coal. Oil and gas - Crude oil and natural gas formed from decaying bodies of tiny sea organisms and plants over millions of years. They have slowly been buried and the heat and pressure from the earth has produced oil and gas.

18 Fossil Fuel Extraction and Use Today we will learn to Explain how to extract coal and oil from the Ground and what they are used for. We will do this by Hearing about extraction techniques used, and why fossil fuels are finite. We will have succeeded if

19 S3 Chemistry Fuels and Climate Chemistry Lesson 2 REVISION By investigating renewable energy sources and taking part in practical activities to harness them, I can discuss their benefits and potential problems SCN 3-04b NEW LEARNING Through investigation, I can explain the formation and use of fossil fuels and contribute to discussions on the responsible use of finite resources SCN 4-04b

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21 Extracting Coal Coal must be removed from the before it can be used. It is from the ground by. This can be deep mining or open cast mining. There were many coal mines in Lanarkshire. Can you name any?

22 Extracting Coal Coal must be removed from the ground before it can be used. It is extracted from the ground by mining. This can be deep pit mining or open cast mining. There were many coal mines in Lanarkshire. Can you name any?

23 Extracting Coal Local History! The industrial revolution was brought about by coal mining. Lesmahagow had a train station to meet demands of coal mining photos Lesmahagow train station This closed in 1954

24 Extracting Oil and Gas Crude oil and are extracted from the earth s by. This is a difficult process, it is only in recent years that has made this possible.

25 Extracting Oil and Gas Crude oil and gas are extracted from the earth s crust by drilling. This is a difficult process, it is only in recent years that technology has made this possible.

26 Formation of oil & natural gas

27 Extracting Oil and Gas Oil is commonly found under the or ancient sea beds which are now! Huge oil are erected and situated far off shore where they for oil which is then pumped to oil.

28 Extracting Oil and Gas Oil is commonly found under the sea or ancient sea beds which are now land! Huge oil rigs are erected and situated far off shore where they drill for oil which is then pumped to oil refineries.

29 1, 2) conventional fixed platforms; 3) compliant tower; 4, 5) vertically moored tension leg and mini-tension leg platform; 6) spar; 7,8) semi-submersibles; 9) floating production, storage, and offloading facility; 10) sub-sea completion and tie-back to host facility

30 Extracting Oil and Gas North Sea Oil Why do we need oil, gas and coal?

31 Make a Key fact Card! Formation and Extraction of Crude Oil Formation and Extraction of Coal

32 Fossil Fuel Extraction and Use Today we will learn to Explain how to extract coal and oil from the ground and what they are used for. We will do this by Hearing about extraction techniques used, and why fossil fuels are finite. We will have succeeded if We can produce a fact card for others detailing the information.

33 Starter Questions 1. Name 3 fossil fuels. Coal, oil and natural gas. 2. Name other things, not including fuels, that crude oil can be used to produce. Plastics, medicines, cosmetics, road tar, paint. 3. Which elements are present in hydrocarbon compounds? Hydrogen and carbon only.

34 Lesson 3: Burning Fossil Fuels Today we will learn to Describe the products when fossil fuels are burned and the role of oxygen in combustion. We will do this by Doing an experiment to burn a hydrocarbon and testing the products. Building models of the products. We will have succeeded if

35 Burning Fossil Fuels Fossil fuels are mainly hydrocarbons with minor impurities. A hydrocarbon is a compound containing and only. Burning fossil fuels means that molecules are reacting with the molecules of the air.

36 Burning Fossil Fuels Fossil fuels are mainly hydrocarbons with minor impurities. A hydrocarbon is a compound containing carbon and hydrogen only. Burning fossil fuels means that hydrocarbon molecules are reacting with the oxygen molecules of the air.

37 Products of Combustion Experiment 5.1

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39 Burning Fossil Fuels Natural gas, a fossil fuel, is a hydrocarbon with the chemical formula CH 4. Natural gas burns in a Bunsen burner. The products of the reaction are oxides of the elements that make up the hydrocarbon. Energy, mainly heat, is also given out.

40 Lesson 3: Burning Fossil Fuels Today we will learn to Describe the products when fossil fuels are burned and the role of oxygen in combustion. We will do this by Doing an experiment to burn a hydrocarbon and testing the products. Building models of the products. We will have succeeded if

41 EXIT TASK - Complete combustion summary fuels (hydrocarbons) burn to produce dioxide and water. For these products to form, a good supply is needed. This is combustion. e.g. lighter fuel + oxygen carbon dioxide + water

42 Complete combustion Fossil fuels (hydrocarbons) burn to produce carbon dioxide and water. For these products to form, a good air supply is needed. This is complete combustion. e.g. lighter fuel + oxygen carbon dioxide + water

43 Starter Question Carbon compounds can undergo a variety of reactions. Using your knowledge of chemistry, comment on some reactions that involve carbon compounds.

44 Lesson 4: Complete and incomplete combustion Today we will learn Which products are made when fossil fuels are burned with sufficient and insufficient oxygen We will do this by Watching a demonstration of incomplete combustion and learning why there is a difference We will have succeeded if

45 Incomplete combustion If there is not oxygen (from the air), the carbon in the will not all be turned into carbon dioxide. This is combustion. Carbon monoxide and carbon (soot) can be produced.

46 Incomplete combustion If there is not enough oxygen (from the air), the carbon in the hydrocarbon will not all be turned into carbon dioxide. This is incomplete combustion. Carbon monoxide and carbon (soot) can be produced,

47 Incomplete combustion e.g. in car engines where the supply of air is limited. With incomplete combustion, the hydrogen from the hydrocarbon still forms water. e.g. petrol + oxygen carbon monoxide + carbon + water

48 Incomplete combustion Experiment 5.2 Put a white tile over the bunsen burner over the safety flame What happens to the tile?

49 Lesson 4: Complete and incomplete combustion Today we will learn Which products are made when fossil fuels are burned with sufficient and insufficient oxygen We will do this by Watching a demonstration of incomplete combustion and learning why there is a difference We will have succeeded if

50 Starter Question Carbon compounds can undergo a variety of reactions. Using your knowledge of chemistry, comment on some reactions that involve carbon compounds.

51 Lesson 5: Air Pollution Today we will learn What air pollution means and where most of the common pollutants come from We will do this by Learn what the main pollutants are and ways to reduce them We will have succeeded if We can name the pollutants and how they are reduced

52 Starter Task Complete the equations: Complete combustion of methane methane + oxygen + water Incomplete combustion of methane methane + oxygen + water

53 Air Pollution Air pollution is a result of in the air. Most of the pollutants come from hydrocarbon fuels from crude oil, e.g. gas, oil, petrol and diesel. Air pollution is therefore more of a in industrial areas.

54 Air Pollution Air pollution is a result of impurities in the air. Most of the pollutants come from burning hydrocarbon fuels from crude oil, e.g. gas, oil, petrol and diesel. Air pollution is therefore more of a problem in industrial areas.

55 Air Pollution As well as the environment, pollution is a hazard, e.g. pollutant gases can contribute to disease and bronchitis.

56 Air Pollution As well as damaging the environment, pollution is a health hazard, e.g. pollutant gases can contribute to lung disease and bronchitis.

57 Air Pollution When a hydrocarbon fuel burns completely, the carbon atoms in the hydrocarbon molecules react with the air to form carbon dioxide. However, incomplete combustion, e.g. petrol burning in a car engine, forms carbon monoxide, a poisonous gas.

58 Air Pollution Crude oil contains small amounts of. The burning of fuels from crude oil therefore produces sulphur dioxide. This gas dissolves in rain water to form rain.

59 Air Pollution Crude oil contains small amounts of sulfur. The burning of fuels from crude oil therefore produces sulfur dioxide. This gas dissolves in rain water to form acid rain.

60 Car exhaust systems can be fitted with a converter. These systems contain transition metals that act as a catalyst for the reaction of carbon monoxide and nitrogen dioxide to carbon dioxide and nitrogen.

61 Car exhaust systems can be fitted with a catalytic converter. These systems contain transition metals that act as a catalyst for the reaction of harmful carbon monoxide and nitrogen dioxide to less harmful carbon dioxide and nitrogen.

62 Another way of decreasing air pollution is to improve the efficiency of combustion. This can be done by increasing the air to fuel ratio. The higher concentration of oxygen is more likely to lead to complete combustion and a consequent decrease in the formation of carbon and carbon monoxide.

63 Exit Task Mr Wrong Explain why this student statement is wrong Acid rain has increased since catalytic converters have been fitted in cars

64 Lesson 5: Air Pollution Today we will learn What air pollution means and where most of the common pollutants come from We will do this by Learn what the main pollutants are and ways to reduce them We will have succeeded if We can name the pollutants and how they are reduced

65 Lesson 6: The Carbon Cycle Today we will learn How the carbon cycle is present in our everyday lives We will do this by Looking at sources of carbon and working out how they are stored We will have succeeded if We can complete a diagram to show how

66 Experiment 5.3 The carbon cycle Place the items in the tray in the correct part of the carbon cycle. Hint some types of carbon are stored in rocks, the ocean and soil. Others are in the atmosphere.

67 You need 5 different coloured highlighters. 7. CO 5. Animals 2 is & returned to the decomposers also atmosphere return CO 2 to the when fossil fuels atmosphere by are burnt respiration. (combustion). CO 2 in the air & dissolved in water (oceans) 3. The carbon taken in by plants is then eaten by animals. 1. Plants 2. CO absorb CO 2 is returned 2 in photosynthesis the air when the and plant make respires. new carbon compounds. 6. Dead material is turned into fossil fuels. 4. Dead plant & animal material is broken down by decomposers. There are also huge amounts of carbon locked into carbonate rocks, e.g. Limestone.

68 You need 5 different coloured highlighters. 7. CO 2 is returned to the atmosphere when fossil fuels are burnt (combustion) 5. Animals & decomposers also return CO 2 to the atmosphere by respiration. CO 2 in the air & dissolved in water (oceans) 2. CO 2 is returned to the air when the plant respires. 3. The carbon taken in by plants is then eaten by animals. 1. Plants absorb CO 2 in photosynthesis and make new carbon compounds. 6. Dead material is turned into fossil fuels. 4. Dead plant & animal material is broken down by decomposers. There are also huge amounts of carbon locked into carbonate rocks, e.g. Limestone.

69 Lesson 7: The Greenhouse Effect Today we will learn How the greenhouse effect is affecting The planet We will do this by Looking at some explanations and diagrams to explain this. Discussing some ideas based on what you know about the carbon cycle We will have succeeded if

70 Why is carbon dioxide increasing? There are two main reasons why the amount of carbon dioxide in our atmosphere is increasing: 1. More trees are being cut down. This means that there are fewer trees to take in carbon dioxide for photosynthesis so more carbon dioxide stays in the air. 2. We are burning more fossil fuels and this makes carbon dioxide gas.

71 Why is carbon dioxide increasing? There are two main reasons why the amount of carbon dioxide in our atmosphere is : 1. More trees are being cut. This means that there are fewer trees to take in carbon dioxide for photosynthesis so more carbon dioxide in the air. 2. We are more fossil fuels and this makes carbon dioxide.

72 Global Warming Scientists have noticed that the earth is gradually getting warmer. They think that this is because the amounts of oxygen and carbon dioxide are getting out of balance. Carbon dioxide is building up in our atmosphere and causes the greenhouse effect. A layer of carbon dioxide makes the heat bounce back to earth, so the earth gets warmer. They call this global warming.

73 Global Warming Scientists have noticed that the earth is gradually getting warmer. They think that this is because the amounts of oxygen and carbon dioxide are getting out of balance. Carbon dioxide is building up in our atmosphere and causes the greenhouse effect. A layer of carbon dioxide makes the heat back to earth, so the earth gets warmer. They call this warming.

74 The Greenhouse effect

75 layer of extra carbon dioxide sun Normally the heat energy from the sun is radiated back again into space but the layer of carbon dioxide makes it bounce back down.

76 Problems of global warming Global warming can cause the weather to change and can also make icebergs melt so that the sea level rises. This can cause flooding in some places. Some people who live on the coast could lose their homes into the sea.

77 carbon dioxide carbon dioxide

78 The Green House Effect Questions 1. What have scientists noticed about the temperature of the earth? 2. What is the name of the main gas that causes the greenhouse effect? 3. Explain how this gas makes the earth get warmer. 4. When the earth gets warm what is this called? 5. What are the two things that are causing carbon dioxide to build up in our atmosphere? 6. Explain why cutting down trees makes the amount of carbon dioxide in the air increase. 7. What sort of things should we do to help prevent the greenhouse effect from getting worse?

79 Answers 1. The temperature is increasing. 2. Carbon dioxide 3. It stops the suns heat escaping into space. 4. Global warming. 5. Cutting down trees and burning fossil fuels 6. Trees take in carbon dioxide during photosynthesis. 7. Stop burning fossil fuels and plant more trees

80 Carbon dioxide emitters carbon dioxide carbon dioxide The balance of carbon in and out of the atmosphere is called the C Cycle. Use as many of the items as you can to show how carbon can be moved between the e and the atmosphere.

81 Lesson 7: The Greenhouse Effect Today we will learn How the greenhouse effect is affecting The planet We will do this by Looking at some explanations and diagrams to explain this. Discussing some ideas based on what you know about the carbon cycle We will have succeeded if

82 Starter Questions 1. Which gas is building up in our atmosphere and causing the greenhouse effect? Carbon dioxide 2. Suggest two reasons why this gas is building up in our atmosphere. 1 We are cutting more trees down 2 We are burning more fossil fuels 3. Which separation technique can be used to separate two liquids with different boiling points? Distillation

83 Lesson 8: Fractional Distillation Today we will learn How fractional distillation is used to separate the different hydrocarbons found in crude oil. We will do this by Watching a demonstration of fractional distillation of crude oil & playing a card game about this topic. We will have succeeded if We can complete a diagram to show how the properties of fractions change as we move down the fractionating column.

84 Fractional Distillation Crude oil is a mixture of hydrocarbons and can be separated into useful parts or fractions by fractional distillation. Groups of hydrocarbons with similar boiling temperatures or points are separated according to their boiling point ranges and collected for different uses.

85 Fractional Distillation Crude oil is a of hydrocarbons and can be into useful parts or by. Groups of hydrocarbons with similar boiling temperatures or points are separated according to their ranges and collected for different uses.

86 Fractional Distillation

87 Fraction Boiling Range Use of Fraction Refinery Gases Naphtha <20 C C Petrol Kerosene Diesel C C C Lubricating Oil C Residue Doesn t boil in column

88 Experiment 5.4

89 NOTES Complete the following diagram by naming the fractions: The fractions are separated by the difference in their ranges. ACTIVITY 6.2 Fractional Distillation Card Games Your teacher may let you play these card games.

90 NOTES Complete the following diagram by naming the fractions: Refinery gases Naptha Petrol Kerosene Diesel Lubricating oil Residue The fractions are separated by the difference in their ranges. Boiling Point ACTIVITY 6.2 Fractional Distillation Card Games Your teacher may let you play these card games.

91 Properties of the Fractions The hydrocarbons are made up of chains of carbon atoms of different lengths, some with only one or two carbon atoms; others with over 70 carbon atoms. The hydrocarbons making up the fractions coming off the top of the tower are the shortest ones; as we go down the column the chains get longer and longer. The length of the chain affects the physical properties of the fractions.

92 Properties of the Fractions The hydrocarbons are made up of of carbon atoms of different, some with only one or two carbon atoms; others with over 70 carbon atoms. The hydrocarbons making up the fractions coming off the top of the tower are the ones; as we go down the column the chains get longer and longer. The of the chain affects the properties of the fractions.

93 Viscosity & Flammability VISCOSITY means how thick or hard to pour a liquid is. e.g. A viscous liquid (like syrup) is thicker than a liquid with low viscosity (like water). FLAMMABILITY means how easily something catches fire. VOLATILTY means how easily something evaporates

94 Viscosity & Flammability VISCOSITY means how or hard to pour a liquid is. e.g. A liquid (like ) is thicker than a liquid with low viscosity (like water). FLAMMABILITY means how something catches fire. VOLATILTY means how something evaporates.

95 How do the properties relate? As the molecules get longer, what happens to the. Boiling Point increases Viscosity increases Flammability decreases Volatility decreases Fraction Refinery Gases Naphtha Petrol Kerosene Diesel Lubricating Oil

96 Crude Oil Fractions Smallest carbon chain Least viscous Most flammable Crude oil enters and is heated here Longest carbon chain Most viscous Least flammable

97 Fraction Number of Carbon Atoms per Molecule A 1 to 4 B C D E (short molecules) 5 to 6 6 to 11 9 to to 25 F > 25 (long molecules) Explain why fraction F has a higher boiling point than fraction B It contains longer molecules. These are more difficult to separate and turn into a gas. Therefore more energy is required for F to boil. Fractional Distillation Column

98 Quick Quiz Fraction Number of Carbon Atoms per Molecule A 1 to 4 B C D E (short molecules) 5 to 6 6 to 11 9 to to 25 F > 25 (long molecules) True or False? fraction C is more viscous than fraction E FALSE Fraction E has longer molecules and will therefore be more viscous than fraction C Fractional Distillation Column

99 Quick Quiz Fraction Number of Carbon Atoms per Molecule A 1 to 4 (short molecules) True or False? fraction F is less flammable than fraction C B 5 to 6 F > 25 (long molecules) Fractional Distillation Column C D E 6 to 11 9 to to 25 TRUE Fraction C has shorter molecules which catch fire more easily.

100 A Fraction 6 evaporated most easily. B Fraction 4 is more viscous than fraction 3. C Fraction 2 is more flammable than fraction 1. D Fraction 5 has a lower boiling range than fraction 4. E The molecules in fraction 3 are larger than those in fraction 2.

101 Lesson 8: Fractional Distillation Today we will learn How fractional distillation is used to separate the different hydrocarbons found in crude oil. We will do this by Watching a demonstration of fractional distillation of crude oil & playing a card game about this topic. We will have succeeded if We can complete a diagram to show how the properties of fractions change as we move down the fractionating column.

102 Starter Questions 1. What is fractional distillation? Separating different fractions depending on their boiling point. 2. Where does this take place? An oil refinery.

103 Lesson 9: Fractional Distillation - uses Today we will learn to State some uses of refined crude oil We will do this by Researching what useful products are made when crude oil is separated using fractional distillation We will have succeeded if

104 Some unusual oil products Nearly everything in our lives is made from oil or made by machinery and systems dependent on oil, and transported by oil as either petrol or diesel. Here are some items which are made from crude oil Any surprises??

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106 Research

107 Lesson 9: Fractional Distillation - uses Today we will learn to State some uses of refined crude oil We will do this by Researching what useful products are made when crude oil is separated using fractional distillation We will have succeeded if

108 Starter Questions 1. Name one useful product from crude oil and which fraction that product is made from. camping stove gas refinery gases tar for roads (bitumen) residue wax for candles lubricating oils 2. What is viscosity? The thickness of a liquid (how easy/hard it is to pour). 3. Which fraction will be most viscous: one collected at the top of the fractionating column or one collected near the bottom? The fraction collected near the bottom.

109 Lesson 10 - Biodiesel Today we will learn to Learn where biodiesel comes from Make biodiesel and test it We will do this by Hearing about how biodiesel is made We will have succeeded if

110 Biodiesel Biodiesel can be produced from waste vegetable oils. These oils come from plants, which get their energy from the Sun. You can always plant more biofuel crops therefore this fuel is renewable unlike fossil fuels which are finite.

111 Biodiesel Biodiesel can be produced from waste oils. These oils come from, which get their energy from. You can always plant more biofuel crops therefore this fuel is unlike fossil fuels which are.

112 Experiment 5.5 Making Biodiesel Aim: Make biodiesel from vegetable oil Method: Measure 10cm 3 of vegetable oil into a test tube Add 2cm 3 of potassium methoxide Stopper the test tube with a bung and shake for 1 minute Leave to settle overnight

113 Starter Questions 1. What is biodiesel made from? Waste vegetable oils 2. Why is it being used to run your school buses? It is made from plants therefore is a renewable resource (you can always make more of it)

114 Making Biodiesel Day 2 Using a pipette remove the top layer into a second test tube Add 2cm 3 of salt solution and invert ten times. (Do not shake as an emulsion can form) Leave to stand for 5 minutes. Transfer the top layer to a third test tube. You have now made bio-diesel and are ready to test it.

115 Fuels Experiment Testing Biodiesel Method: Pour some oil into the empty test tube so the depth is the same as the biodiesel you have. Tear two small pieces from the end of the ph paper you have. Make sure they are small enough not to get caught in the test tubes. At the same time, add a piece to each test tube and shake them gently to make sure the paper gets wet and starts to sink into the liquids. Watch how fast they sink and if they change colour. Try to match the colour of each piece of ph paper to a number on the chart you have. Aim: To test the ph, viscosity and flammability of biodiesel

116 Table of Results Property ph Viscosity Flammability Result

117 Lesson 10 - Biodiesel Today we will learn to Learn where biodiesel comes from Make biodiesel and test it We will do this by Hearing about how biodiesel is made We will have succeeded if

118 Starter Questions 1. Name 2 properties of biodiesel ph <7, viscous 2. What is a hydrocarbon? A compound that contains carbon and hydrogen only

119 Lesson 11: Alkanes Today we will learn About the formulae and structures of the members of the hydrocarbon family called alkanes. We will do this by Building molecular models of alkanes, and drawing them. We will have succeeded if We can use molecular formulae, full structural formulae and shortened structural formulae when dealing with the first 8 alkanes and their isomers.

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121 Alkanes

122 Alkanes

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126 Lesson 11: Alkanes Today we will learn About the formulae and structures of the members of the hydrocarbon family called alkanes. We will do this by Building molecular models of alkanes, and drawing them. We will have succeeded if We can use molecular formulae, full structural formulae and shortened structural formulae when dealing with the first 8 alkanes and their isomers.

127 Starter Questions 1. What is biodiesel made from? Waste vegetable oils 2. Why is it being used to run your school buses? It is made from plants therefore is a renewable resource (you can always make more of it)

128 Lesson 12: Cracking Today we will learn to How to get the most from oil by catalytic cracking of alkanes We will do this by Carrying out catalytic cracking of paraffin. We will have succeeded if We can describe how to carry out catalytic cracking and explain why it is used.

129 Catalytic Cracking The distillation of crude oil produces a high percentage of longer, less useful molecules giving insufficient fuel fractions to meet market demand. Chemists have developed a process called Catalytic Cracking to solve this problem.

130 Catalytic Cracking Experiment 5.7

131 Catalytic Cracking When the paraffin is heated, it changes into a gas. As the paraffin gas passes over the Aluminium Oxide it reacts on the surface. The Aluminium Oxide acts as a catalyst for the reaction. The main advantage of using a catalyst in industry is that it allows the reaction to take place at lower temperature. In cracking as well as producing shorter more useful alkanes another type of hydrocarbon is produced called alkenes.

132 Lesson 12: Cracking Today we will learn to How to get the most from oil by catalytic cracking of alkanes We will do this by Carrying out catalytic cracking of paraffin. We will have succeeded if We can describe how to carry out catalytic cracking and explain why it is used.

133 Starter Questions 1. What is the alkane with 3 carbons called? Propane 2. Why do oil companies use catalytic cracking? To break longer chain alkanes into smaller, more useful molecules.

134 Lesson 13: Alkenes Today we will learn About the formulae and structures of the members of the hydrocarbon family called alkenes. We will do this by Building molecular models of alkenes, and drawing them. We will have succeeded if We can use molecular formulae and full structural formulae when dealing with the first 8 alkenes and their isomers.

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136 Alkenes

137 Alkenes

138 Saturation and Unsaturation Alkanes have single C-C bonds in their molecules and are said to be SATURATED i.e. no more hydrogen can be added on. Alkenes can undergo addition reactions across the C=C double bond and are said to be UNSATURATED. E.g

139 Testing for Unsaturation Pupil Experiment Bromine Water Aim: To distinguish between a saturated and an unsaturated hydrocarbon. Method: Collect two test tubes and place 2ml of each hydrocarbon in a test tube. Add bromine water and shake vigourously. Record your immediate findings in a table. Leave the test tubes and observe any further colour changes after minutes.

140 Testing for Unsaturation Pupil Experiment Bromine Water Results: Hydrocarbon Saturated or Unsaturated Immediate Observation Observation after 10-15min

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143 Lesson 13: Alkenes Today we will learn About the formulae and structures of the members of the hydrocarbon family called alkenes. We will do this by Building molecular models of alkenes, and drawing them. We will have succeeded if We can use molecular formulae, full structural formulae and shortened structural formulae when dealing with the First 4 alkenes and their isomers.