1. IGCSE CHEMISTRY SECTION 5 LESSON 2

2. Content The iGCSE Chemistry course Section 1 Principles of Chemistry Section 2 Chemistry of the Elements Section 3 Organic Chemistry Section 4 Physical Chemistry Section 5 Chemistry in Society

3. Content Section 5 Chemistry in industry a)Extraction and uses of metals b)Crude oil c)Synthetic polymers d)The industrial manufacture of chemicals

4. Lesson 2 b) Crude oil 5.6 understand that crude oil is a mixture of hydrocarbons 5.7 describe and explain how the industrial process of fractional distillation separates crude oil into fractions 5.8 recall the names and uses of the main fractions obtained from crude oil: refinery gases, gasoline, kerosene, diesel, fuel oil and bitumen 5.9 describe the trend in boiling point and viscosity of the main fractions 5.10 understand that incomplete combustion of fuels may produce carbon monoxide and explain that carbon monoxide is poisonous because it reduces the capacity of the blood to carry oxygen 5.11 understand that, in car engines, the temperature reached is high enough to allow nitrogen and oxygen from air to react, forming nitrogen oxides 5.12 understand that nitrogen oxides and sulfur dioxide are pollutant gases which contribute to acid rain, and describe the problems caused by acid rain 5.13 understand that fractional distillation of crude oil produces more long-chain hydrocarbons than can be used directly and fewer short-chain hydrocarbons than required and explain why this makes cracking necessary 5.14 describe how long-chain alkanes are converted to alkenes and shorter-chain alkanes by catalytic cracking, using silica or alumina as the catalyst and a temperature in the range of 600– 700 o C.

5. Crude Oil

7. Crude oil is a dark, viscous, liquid mixture of many different hydrocarbons

8. Crude Oil Viscous means that it does not flow easily.

9. Crude Oil A hydrocarbon is a compound containing hydrogen and carbon only

10. Crude Oil Crude oil was formed from the decomposition of animals and plants under pressure

11. Crude Oil Massive oil rigs are used to drill underground to extract the crude oil. These oil rigs may be on land, or out at sea as shown here.

12. Crude Oil Massive oil rigs are used to drill underground to extract the crude oil. These oil rigs may be on land, or out at sea as shown here. The crude oil is piped ashore or carried in huge oil tankers to oil refineries where the crude oil is used to make useful products.

13. Crude Oil

14. Oil refineries are huge industrial complexes where crude oil is initially refined by a process known as fractional distillation.

15. Fractional Distillation of Crude Oil Fractional distillation splits crude oil up into its separate parts, or fractions.

16. Fractional Distillation of Crude Oil Fractional distillation splits crude oil up into its separate parts, or fractions. This distillation takes place in a fractionating column.

17. Fractional Distillation of Crude Oil Fractional distillation splits crude oil up into its separate parts, or fractions. This distillation takes place in a fractionating column.

18. Fractional Distillation of Crude Oil Fractional distillation splits crude oil up into its separate parts, or fractions. This distillation takes place in a fractionating column. Crude oil is heated until it becomes gaseous, and it is then piped in to the bottom of the column.

19. Fractional Distillation of Crude Oil As the vapour travels up the fractionating column the different fractions condense into liquids and are constantly tapped off.

20. Fractional Distillation of Crude Oil Crude oil is a mixture of hydrocarbons of different sized molecules.

21. Fractional Distillation of Crude Oil Crude oil is a mixture of hydrocarbons of different sized molecules. Hydrocarbons are basically fuels such as petrol and diesel.

22. Fractional Distillation of Crude Oil Crude oil is a mixture of hydrocarbons of different sized molecules. Hydrocarbons are basically fuels such as petrol and diesel. The shorter the molecules, the lower the temperature at which that fraction condenses – i.e. higher up the fractionating column.

23. Fractional Distillation of Crude Oil Number of carbon atoms in the hydrocarbon chain Crude oil (vapour)

24. Fractional Distillation of Crude Oil Number of carbon atoms in the hydrocarbon chain Crude oil (vapour) ~ 40 Bitumen

25. Fractional Distillation of Crude Oil Number of carbon atoms in the hydrocarbon chain Crude oil (vapour) ~ 40 Bitumen ~ 35 340 o C Oil

26. Fractional Distillation of Crude Oil Number of carbon atoms in the hydrocarbon chain Crude oil (vapour) ~ 40 Bitumen ~ 35 340 o C Oil ~ 20 250 o C Diesel

27. Fractional Distillation of Crude Oil Number of carbon atoms in the hydrocarbon chain Crude oil (vapour) ~ 40 Bitumen ~ 35 340 o C Oil ~ 20250 o C Diesel ~ 10-15 110oC-180 o C Naphtha, Kerosine

28. Fractional Distillation of Crude Oil Number of carbon atoms in the hydrocarbon chain Crude oil (vapour) ~ 40 Bitumen ~ 35 340 o C Oil ~ 20250 o C Diesel ~ 10-15 110 o C-180 o C Naphtha, Kerosine 40 o C Petrol~ 8

29. Fractional Distillation of Crude Oil Number of carbon atoms in the hydrocarbon chain Crude oil (vapour) ~ 40 Bitumen ~ 35 340 o C Oil ~ 20250 o C Diesel ~ 10-15 110 o C-180 o C Naphtha, Kerosine 40 o C Petrol~ 8 Refinery gas (bottled gas) ~ 3

30. Fractional Distillation of Crude Oil Number of carbon atoms in the hydrocarbon chain Crude oil (vapour) ~ 40 Bitumen ~ 35 340 o C Oil ~ 20250 o C Diesel ~ 10-15 110 o C-180 o C Naphtha, Kerosine 40 o C Petrol~ 8 Refinery gas (bottled gas) ~ 3 Crude oil provides the fuel for most modern transport

31. Fractional Distillation of Crude Oil Number of carbon atoms in the hydrocarbon chain Crude oil (vapour) ~ 40 Bitumen ~ 35 340 o C Oil ~ 20250 o C Diesel ~ 10-15 110 o C-180 o C Naphtha, Kerosine 40 o C Petrol~ 8 Refinery gas (bottled gas) ~ 3 Crude oil provides the fuel for most modern transport It also provides the raw material for making various chemicals, including PLASTICS

32. HYDROCARBONS

33. Hydrocarbons are long chain molecules

34. HYDROCARBONS Hydrocarbons are long chain molecules As the size of the hydrocarbon molecule increases

35. HYDROCARBONS Hydrocarbons are long chain molecules As the size of the hydrocarbon molecule increases The BOILING POINT increases

36. HYDROCARBONS Hydrocarbons are long chain molecules As the size of the hydrocarbon molecule increases The BOILING POINT increases It gets LESS FLAMMABLE (doesn’t set fire so easily)

37. HYDROCARBONS Hydrocarbons are long chain molecules As the size of the hydrocarbon molecule increases The BOILING POINT increases It gets LESS FLAMMABLE (doesn’t set fire so easily) It gets MORE VISCOUS (doesn’t flow so easily)

38. Cracking hydrocarbons

39. fractional distillation of crude oil produces more long-chain hydrocarbons than can be used directly and fewer short-chain hydrocarbons than required

40. Cracking hydrocarbons This means that longer molecules such as diesel produced from fractional distribution are cracked into smaller molecules such as petrol and aviation fuel for which there is a greater demand.

41. Cracking hydrocarbons More importantly, cracking produces chemicals such as ethene which are needed for making plastics

42. Cracking hydrocarbons Diesel Petrol Aviation fuel Ethene for plastics HEAT

43. Cracking hydrocarbons Diesel Petrol Aviation fuel Ethene for plastics HEAT THERMAL DECOMPOSITION

44. Industrial Cracking Vaporised kerosine Octane + Ethene Aluminium oxide (alumina) catalyst

45. Industrial Cracking Vaporised kerosine Octane + Ethene Aluminium oxide (alumina) catalyst Vaporised hydrocarbons are passed over a powdered catalyst (Al 2 O 3 ) at between 400-700 o C

46. Industrial Cracking Vaporised kerosine Octane + Ethene Aluminium oxide (alumina) catalyst Vaporised hydrocarbons are passed over a powdered catalyst (Al 2 O 3 ) at between 400-700 o C The longer chain molecules ‘crack’ or split apart on the surface of the bits of catalyst

47. Industrial Cracking HHHH C = C + H HH H Kerosine (ten C atoms) C 10 H 22 Octane (eight C atoms) C 8 H 18 Ethene C 2 H 4 Long chain hydrocarbon molecule Shorter alkane molecule, useful for petrol Useful for making plastics

48. When fuels burn ……

49. 1. Complete combustion of a hydrocarbon in oxygen eg. Methane + Oxygen  Carbon + Water dioxide CH 4 + 2O 2  CO 2 + 2H 2 O

50. When fuels burn …… 1. Complete combustion of a hydrocarbon in oxygen eg. Methane + Oxygen  Carbon + Water dioxide CH 4 + 2O 2  CO 2 + 2H 2 O All products are clean and non-poisonous. Gas room heaters will burn with a clean BLUE flame if the room is well ventilated and there’s plenty of oxygen.

51. When fuels burn …… 2. incomplete combustion of a hydrocarbon in limited oxygen eg. Methane + Oxygen  Carbon + Water + Carbon + Carbon dioxide monoxide 4CH 4 + 6O 2  CO 2 + 8H 2 O + 2CO + C

52. When fuels burn …… 2. incomplete combustion of a hydrocarbon in limited oxygen eg. Methane + Oxygen  Carbon + Water + Carbon + Carbon dioxide monoxide 4CH 4 + 6O 2  CO 2 + 8H 2 O + 2CO + C Incomplete combustion also produces carbon monoxide and carbon. Gas heaters will burn with a smoky YELLOW flame. Carbon monoxide is a colourless, odourless and poisonous gas. If the room is not well ventilated with plenty of oxygen then this deadly gas is produced.

53. Carbon monoxide poisoning

54. Normally, oxygen is carried in the blood by combining with haemoglobin in red blood cells to form oxyhaemoglobin.

55. Carbon monoxide poisoning Normally, oxygen is carried in the blood by combining with haemoglobin in red blood cells to form oxyhaemoglobin. When carbon monoxide is present it combines with haemoglobin to form carboxyhaemoglobin

56. Carbon monoxide poisoning Normally, oxygen is carried in the blood by combining with haemoglobin in red blood cells to form oxyhaemoglobin. When carbon monoxide is present it combines with haemoglobin to form carboxyhaemoglobin This prevents oxygen binding to haemoglobin, reducing the oxygen-carrying capacity of the blood. This leads to hypoxia.

57. Carbon monoxide poisoning Normally, oxygen is carried in the blood by combining with haemoglobin in red blood cells to form oxyhaemoglobin. When carbon monoxide is present it combines with haemoglobin to form carboxyhaemoglobin This prevents oxygen binding to haemoglobin, reducing the oxygen-carrying capacity of the blood. This leads to hypoxia. Hypoxia = condition in which the body is deprived of an adequate oxygen supply. Severe carbon monoxide poisoning and oxygen deprivation can ultimately result in death.

58. Cars and pollution

59. Nitrogen and oxygen in the air

60. Cars and pollution Nitrogen and oxygen in the air High temperatures

61. Cars and pollution Nitrogen and oxygen in the air High temperatures Nitrogen oxides NO, NO 2

62. Cars and pollution Nitrogen and oxygen in the air High temperatures Nitrogen oxides NO, NO 2 React with water in clouds

63. Cars and pollution Nitrogen and oxygen in the air High temperatures Nitrogen oxides NO, NO 2 React with water in clouds Formation of ACID RAIN

64. Air Pollution Sulphur dioxide and nitrogen oxides Gases react with water in the atmosphere to form ….. Nitrogen oxides Industry and power stationsMotor cars ACID RAIN

65. Air Pollution Sulphur dioxide and nitrogen oxides Gases react with water in the atmosphere to form ….. Nitrogen oxides Industry and power stationsMotor cars ACID RAIN CARS AND POWER STATIONS ARE THE MAIN CAUSES OF ACID RAIN

66. Air Pollution Effects of acid rain

67. Air Pollution Effects of acid rain www.sciencedaily.com Acid rain causes lakes to become acidic and many plants and animals die as a result.

68. Air Pollution Effects of acid rain Acid rain damages statues and stone buildings by reacting chemically with the stone, removing details of features and destroying their beauty. www.nachi.org

69. End of Section 5 Lesson 2 In this lesson we have covered: Crude oil Fractional distillation of crude oil Cracking hydrocarbons When fuels burn … Cars and air pollution