1. Chapter 9 Carbon Chemistry

2. 9.1 Carbon CompoundsCarbon Chemistry 9.1 Carbon Compounds Until 1828, chemists divided compounds into compounds that chemist could produce and compounds that only organisms could produce. Until 1828, chemists divided compounds into compounds that chemist could produce and compounds that only organisms could produce. The compounds produced by organisms were called organic compounds. The compounds produced by organisms were called organic compounds.

3. 9.1 Carbon CompoundsCarbon Chemistry An organic compound contains carbon and hydrogen, often combined with other elements. An organic compound contains carbon and hydrogen, often combined with other elements. Organic compounds make up more than 90 % of all known compounds. Organic compounds make up more than 90 % of all known compounds.

4. 9.1 Carbon CompoundsCarbon Chemistry Carbon has four valence electrons and can form Carbon has four valence electrons and can form –four single covalent bonds –a double bond and two single bonds –a triple bond and a single bond

5. 9.1 Carbon CompoundsCarbon Chemistry Forms of Carbon Carbon exists in several different forms with different properties. Carbon exists in several different forms with different properties. Forms include diamond, graphite, and fullerenes each with a different arrangement of bonded carbon atoms. Forms include diamond, graphite, and fullerenes each with a different arrangement of bonded carbon atoms.

6. 9.1 Carbon CompoundsCarbon Chemistry Forms of Elemental Carbon Forms of Elemental Carbon

7. 9.1 Carbon CompoundsCarbon Chemistry Forms of Elemental Carbon Forms of Elemental Carbon

8. 9.1 Carbon CompoundsCarbon Chemistry Forms of Elemental Carbon Forms of Elemental Carbon

9. 9.1 Carbon CompoundsCarbon ChemistryDiamond Diamond is an example of a network solid. Diamond is an example of a network solid. In a network solid, all the atoms are linked by covalent bonds. In a network solid, all the atoms are linked by covalent bonds. A network solid is sometimes described as a single molecule. A network solid is sometimes described as a single molecule.

10. 9.1 Carbon CompoundsCarbon Chemistry Covalent bonds connect each carbon atom in diamond to four other carbon atoms. Covalent bonds connect each carbon atom in diamond to four other carbon atoms. Diamond is harder than all other natural substances. Diamond is harder than all other natural substances.

11. 9.1 Carbon CompoundsCarbon ChemistryGraphite Graphite is extremely soft and slippery because the carbon atoms are arranged in widely spaced layers. Graphite is extremely soft and slippery because the carbon atoms are arranged in widely spaced layers. The bonds between graphite layers are weak, which allows them to slide easily past one another. The bonds between graphite layers are weak, which allows them to slide easily past one another. Pencil “lead” is a mixture of graphite and clay. Pencil “lead” is a mixture of graphite and clay.

12. 9.1 Carbon CompoundsCarbon ChemistryFullerenes Fullerenes are large hollow spheres or cages of carbon. Fullerenes are large hollow spheres or cages of carbon. On the surface of the cage, the atoms form alternating hexagons and pentagons. On the surface of the cage, the atoms form alternating hexagons and pentagons.

13. 9.1 Carbon CompoundsCarbon Chemistry Saturated Hydrocarbons A hydrocarbon is an organic compound that contains only hydrogen and carbon. A hydrocarbon is an organic compound that contains only hydrogen and carbon. In a saturated hydrocarbon, all the bonds are single bonds. In a saturated hydrocarbon, all the bonds are single bonds.

14. 9.1 Carbon CompoundsCarbon Chemistry A saturated hydrocarbon contains the maximum possible number of hydrogen atoms for each carbon atom. A saturated hydrocarbon contains the maximum possible number of hydrogen atoms for each carbon atom. Saturated hydrocarbons are also called alkanes. Saturated hydrocarbons are also called alkanes.

15. 9.1 Carbon CompoundsCarbon Chemistry Factors that determine the properties of a hydrocarbon are the number of carbon atoms and how those atoms are arranged. Factors that determine the properties of a hydrocarbon are the number of carbon atoms and how those atoms are arranged. Arrangements include straight chain, branched chain, and ring. Arrangements include straight chain, branched chain, and ring.

16. 9.1 Carbon CompoundsCarbon Chemistry Types of Alkanes

17. 9.1 Carbon CompoundsCarbon Chemistry Straight Chains A molecular formula shows the type and number of atoms in a molecule of the compound. A molecular formula shows the type and number of atoms in a molecule of the compound. A structural formula shows how those atoms are arranged. A structural formula shows how those atoms are arranged.

18. 9.1 Carbon CompoundsCarbon Chemistry

19. 9.1 Carbon CompoundsCarbon Chemistry The number of carbon atoms in a straight-chain alkane affects the state of the alkane at room temperature. The number of carbon atoms in a straight-chain alkane affects the state of the alkane at room temperature. –Methane and propane are gases –Pentane and octane are liquids. The more carbon atoms, the higher the boiling point is. The more carbon atoms, the higher the boiling point is.

20. 9.1 Carbon CompoundsCarbon Chemistry Branched Chains Compounds with the same molecular formula but different structural formulas are isomers. Compounds with the same molecular formula but different structural formulas are isomers. Differences in structure affect some properties of isomers. Differences in structure affect some properties of isomers. Butane boils at –0.5 o C, but isobutane boils at –11.7 o C. Butane boils at –0.5 o C, but isobutane boils at –11.7 o C.

21. 9.1 Carbon CompoundsCarbon Chemistry

22. 9.1 Carbon CompoundsCarbon ChemistryRings The carbon atoms in cyclobutane are linked in a four-carbon ring. The carbon atoms in cyclobutane are linked in a four-carbon ring.

23. 9.1 Carbon CompoundsCarbon Chemistry Unsaturated Hydrocarbons A hydrocarbon that contains one or more double or triple bonds is an unsaturated hydrocarbon. A hydrocarbon that contains one or more double or triple bonds is an unsaturated hydrocarbon. They are classified by bond type and the arrangement of their carbon atoms. They are classified by bond type and the arrangement of their carbon atoms.

24. 9.1 Carbon CompoundsCarbon Chemistry There are three types of unsaturated hydrocarbons There are three types of unsaturated hydrocarbons –alkenes –alkynes –aromatic hydrocarbons

25. 9.1 Carbon CompoundsCarbon Chemistry

26. 9.1 Carbon CompoundsCarbon ChemistryAlkenes There is a double bond between the two carbon atoms in ethene. There is a double bond between the two carbon atoms in ethene. Hydrocarbons that have one or more carbon-carbon double bonds are alkenes. Hydrocarbons that have one or more carbon-carbon double bonds are alkenes.

27. 9.1 Carbon CompoundsCarbon Chemistry

28. 9.1 Carbon CompoundsCarbon ChemistryAlkynes Ethyne(C 2 H 2 ), also known as acetylene, is an alkyne. Ethyne(C 2 H 2 ), also known as acetylene, is an alkyne. Alkynes are straight- or branched- chain hydrocarbons that have one or more triple bonds. Alkynes are straight- or branched- chain hydrocarbons that have one or more triple bonds. Alkynes are the most reactive hydrocarbon compounds. Alkynes are the most reactive hydrocarbon compounds.

29. 9.1 Carbon CompoundsCarbon Chemistry Aromatic Hydrocarbons Benzene (C 6 H 6 ) is an unsaturated hydrocarbon with a ring structure. Benzene (C 6 H 6 ) is an unsaturated hydrocarbon with a ring structure. Six of the valence electrons are shared by all six carbon atoms. Six of the valence electrons are shared by all six carbon atoms. Hydrocarbons that contain similar ring structures are known as aromatic hydrocarbons because many of these compounds have strong aromas. Hydrocarbons that contain similar ring structures are known as aromatic hydrocarbons because many of these compounds have strong aromas.

30. 9.1 Carbon CompoundsCarbon Chemistry

31. 9.1 Carbon CompoundsCarbon Chemistry The terms saturated and unsaturated are also used to describe fats. The terms saturated and unsaturated are also used to describe fats. The term fat is used to refer to the fats and oils obtained from plants and animals. The term fat is used to refer to the fats and oils obtained from plants and animals.

32. 9.1 Carbon CompoundsCarbon Chemistry If the hydrocarbon chains contain only single bonds, the fat is classified as a saturated. If the hydrocarbon chains contain only single bonds, the fat is classified as a saturated. If there are one or more double or triple bonds, then it is classified as an unsaturated fat. If there are one or more double or triple bonds, then it is classified as an unsaturated fat.

33. 9.1 Carbon CompoundsCarbon Chemistry Unsaturated fats are generally liquids at room temperature. Unsaturated fats are generally liquids at room temperature. Saturated fats tend to be solids at room temperature. Saturated fats tend to be solids at room temperature. A diet high in saturated fats has been linked to heart disease. A diet high in saturated fats has been linked to heart disease.

34. 9.1 Carbon CompoundsCarbon Chemistry Fossil Fuels Fossils fuels are mixtures of hydrocarbons that formed from remains of plants or animals. Fossils fuels are mixtures of hydrocarbons that formed from remains of plants or animals. Three types of fossil fuels are Three types of fossil fuels are –coal –natural gas –petroleum

35. 9.1 Carbon CompoundsCarbon ChemistryCoal Coal is a solid fossil fuel that began to form millions of years ago as plants in ancient swamps. Coal is a solid fossil fuel that began to form millions of years ago as plants in ancient swamps. Most of the hydrocarbons in coal are aromatic hydrocarbons with high molar masses. Most of the hydrocarbons in coal are aromatic hydrocarbons with high molar masses. These compounds have a high ratio of carbon to hydrogen. These compounds have a high ratio of carbon to hydrogen.

36. 9.1 Carbon CompoundsCarbon Chemistry Burning coal produces more soot than burning other fossil fuels. Burning coal produces more soot than burning other fossil fuels. Coal forms in four stages: Coal forms in four stages: –Peat –Lignite –Bituminous coal –Anthracite (metamorphic rock)

37. 9.1 Carbon CompoundsCarbon Chemistry

38. 9.1 Carbon CompoundsCarbon Chemistry Natural Gas The second main fossil fuel, natural gas, formed from the remains of marine organisms. The second main fossil fuel, natural gas, formed from the remains of marine organisms. The main component of natural gas is methane. The main component of natural gas is methane. It also contains ethane, propane, and isomers of butane. It also contains ethane, propane, and isomers of butane.

39. 9.1 Carbon CompoundsCarbon ChemistryPetroleum The third main fossil fuel, petroleum, often known as crude oil, is a complex liquid mixture of hydrocarbons formed from remains of marine organisms. The third main fossil fuel, petroleum, often known as crude oil, is a complex liquid mixture of hydrocarbons formed from remains of marine organisms. Petroleum is separated through fractional distillation. Petroleum is separated through fractional distillation.

40. 9.1 Carbon CompoundsCarbon Chemistry When petroleum is heated in a distillation tower, most of the hydrocarbons vaporize. When petroleum is heated in a distillation tower, most of the hydrocarbons vaporize. The vapors rise through the tower and condense as the temperature decreases. The vapors rise through the tower and condense as the temperature decreases. See figure 8 on page 268. See figure 8 on page 268.

41. 9.1 Carbon CompoundsCarbon Chemistry

42. 9.1 Carbon CompoundsCarbon Chemistry

43. 9.1 Carbon CompoundsCarbon Chemistry

44. 9.1 Carbon CompoundsCarbon Chemistry Combustion of Fossil Fuels The primary products of complete combustion of fossils fuels are carbon dioxide and water. The primary products of complete combustion of fossils fuels are carbon dioxide and water. Some sulfur and nitrogen are in fossil fuels, and air contains 78% nitrogen. Some sulfur and nitrogen are in fossil fuels, and air contains 78% nitrogen. The combustion of fossil fuels produces nitrogen oxides and sulfur dioxide. The combustion of fossil fuels produces nitrogen oxides and sulfur dioxide.

45. 9.1 Carbon CompoundsCarbon Chemistry Acid Rain The combustion of fossil fuels causes the acidity of rain to increase. The combustion of fossil fuels causes the acidity of rain to increase. Rain is slightly acidic, with a pH of about 5.6, because carbon dioxide dissolves in water and forms carbonic acid, H 2 CO 3. Rain is slightly acidic, with a pH of about 5.6, because carbon dioxide dissolves in water and forms carbonic acid, H 2 CO 3.

46. 9.1 Carbon CompoundsCarbon Chemistry Sulfur dioxide and nitrogen oxides released into the atmosphere also dissolve in water, forming sulfuric acid H 2 SO 4, and nitric acid, HNO 3. Sulfur dioxide and nitrogen oxides released into the atmosphere also dissolve in water, forming sulfuric acid H 2 SO 4, and nitric acid, HNO 3. The pH of rain containing sulfuric acid and nitric acid can be as low as 2.7. The pH of rain containing sulfuric acid and nitric acid can be as low as 2.7.

47. 9.2 Substituted HydrocarbonsCarbon Chemistry 9.2 Substituted Hydrocarbons Organic compounds containing chlorine or other halogens are halocarbons. Organic compounds containing chlorine or other halogens are halocarbons. Researchers have established that halocarbons containing chlorine and fluorine deplete Earth’s protective ozone layer. Researchers have established that halocarbons containing chlorine and fluorine deplete Earth’s protective ozone layer.

48. 9.2 Substituted HydrocarbonsCarbon Chemistry The manufacture of chlorofluorocarbons (CFC’s) has been restricted since 1990. The manufacture of chlorofluorocarbons (CFC’s) has been restricted since 1990. A hydrocarbon in which one or more hydrogen atoms have been replaced by an atom or group of atoms is a substituted hydrocarbon. A hydrocarbon in which one or more hydrogen atoms have been replaced by an atom or group of atoms is a substituted hydrocarbon.

49. 9.2 Substituted HydrocarbonsCarbon ChemistryAlcohols The name of an alcohol ends in –ol. The name of an alcohol ends in –ol. The functional group in an alcohol is a hydroxyl group, –OH. The functional group in an alcohol is a hydroxyl group, –OH. When a halocarbon reacts with a base, the products are an alcohol and salt. When a halocarbon reacts with a base, the products are an alcohol and salt. CH 3 Cl + NaOH → CH 3 OH + NaCl

50. 9.2 Substituted HydrocarbonsCarbon Chemistry Organic Acids and Bases The sour taste of a lemon comes from citric acid, an organic acid, C 3 H 4 (COOH) 3. The sour taste of a lemon comes from citric acid, an organic acid, C 3 H 4 (COOH) 3. The functional group in organic acids is a carboxyl group, –COOH. The functional group in organic acids is a carboxyl group, –COOH.

51. 9.2 Substituted HydrocarbonsCarbon Chemistry The simplest organic acid is methanoic acid, HCOOH, known as formic acid. The simplest organic acid is methanoic acid, HCOOH, known as formic acid. Vinegar is a solution of water and organic acid ethanoic acid, CH 3 COOH referred to as acetic acid. Vinegar is a solution of water and organic acid ethanoic acid, CH 3 COOH referred to as acetic acid.

52. 9.2 Substituted HydrocarbonsCarbon Chemistry Amines are organic bases. Amines are organic bases. The functional group in an amine is an amino group –NH 2. The functional group in an amine is an amino group –NH 2.

53. 9.2 Substituted HydrocarbonsCarbon ChemistryEsters Esters form when organic acids react with alcohol. Esters form when organic acids react with alcohol. Esters account for the flavors of many foods and pleasant odor of many flowers. Esters account for the flavors of many foods and pleasant odor of many flowers.

54. 9.3 PolymersCarbon Chemistry 9.3 Polymers A polymer is a large molecule that forms when many smaller molecules are linked together by covalent bonds. A polymer is a large molecule that forms when many smaller molecules are linked together by covalent bonds. The smaller molecules are called monomers. The smaller molecules are called monomers. Polymers can be classified as natural polymers or synthetic polymers. Polymers can be classified as natural polymers or synthetic polymers.

55. 9.3 PolymersCarbon Chemistry Synthetic Polymers The properties of a polymer depend on the type and number of monomers in the polymer. The properties of a polymer depend on the type and number of monomers in the polymer. Rubber, nylon, and polyethylene are three examples of compounds that can be synthesized. Rubber, nylon, and polyethylene are three examples of compounds that can be synthesized. The sap collected from rubber trees in the tropics contains rubber. The sap collected from rubber trees in the tropics contains rubber.

56. 9.3 PolymersCarbon Chemistry Natural rubber collected from trees is soft and sticky. Natural rubber collected from trees is soft and sticky. In 1839, Charles Goodyear found that when sulfur is added to rubber and the mixture is heated, the rubber is no longer sticky. In 1839, Charles Goodyear found that when sulfur is added to rubber and the mixture is heated, the rubber is no longer sticky. The process is called vulcanization. The process is called vulcanization.

57. 9.3 PolymersCarbon Chemistry Natural Polymers Almost all of the large molecules produced by organisms are polymers. Almost all of the large molecules produced by organisms are polymers. Four types of polymers produced in plant and animal cells are starches, cellulose, nucleic acids, and proteins. Four types of polymers produced in plant and animal cells are starches, cellulose, nucleic acids, and proteins.

58. 9.3 PolymersCarbon ChemistryStarches Simple sugars, like glucose, have the formula C 6 H 12 O 6. Simple sugars, like glucose, have the formula C 6 H 12 O 6. Glucose monomers join to form starches. Glucose monomers join to form starches. Simple sugars, slightly more complex sugars, and polymers built from sugar monomers are classified as carbohydrates. Simple sugars, slightly more complex sugars, and polymers built from sugar monomers are classified as carbohydrates.

59. 9.3 PolymersCarbon ChemistryCellulose The carbohydrate cellulose is the main component of cotton and wood. The carbohydrate cellulose is the main component of cotton and wood. It is the most abundant of all organic compounds found in nature. It is the most abundant of all organic compounds found in nature. Most animals cannot digest cellulose. Most animals cannot digest cellulose.

60. 9.3 PolymersCarbon Chemistry Nucleic Acids Nucleic acids are large nitrogen- containing polymers found mainly in the nuclei of cells. Nucleic acids are large nitrogen- containing polymers found mainly in the nuclei of cells. There are two types of nucleic acid, deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). There are two types of nucleic acid, deoxyribonucleic acid (DNA) and ribonucleic acid (RNA).

61. 9.3 PolymersCarbon Chemistry Monomers in a nucleic acid are nucleotides. Monomers in a nucleic acid are nucleotides. The three parts of a DNA nucleotide are a phosphate group, a deoxyribose sugar, and an organic base. The three parts of a DNA nucleotide are a phosphate group, a deoxyribose sugar, and an organic base.

62. 9.3 PolymersCarbon Chemistry The bases in DNA are The bases in DNA are –adenine –thymine –cytosine –guanine

63. 9.3 PolymersCarbon Chemistry The adenine base always pairs up with a thymine base and a cytosine base always pairs up with a guanine base. The adenine base always pairs up with a thymine base and a cytosine base always pairs up with a guanine base. They are arranged like the rungs of a ladder and the strands twist around each other in a structure called a double helix. They are arranged like the rungs of a ladder and the strands twist around each other in a structure called a double helix.

64. 9.3 PolymersCarbon Chemistry

65. 9.3 PolymersCarbon ChemistryProteins Organic acids contain a –COOH group and organic bases, or amines, contain an –NH 2 group. Organic acids contain a –COOH group and organic bases, or amines, contain an –NH 2 group. An amino acid is a compound that contains both carboxyl and amino functional groups in the same molecule. An amino acid is a compound that contains both carboxyl and amino functional groups in the same molecule.

66. 9.3 PolymersCarbon Chemistry Your cells use amino acids as the monomers for constructing protein polymers. Your cells use amino acids as the monomers for constructing protein polymers. A protein is a polymer in which at least 100 amino acid monomers are linked through bonds between an amino group and a carboxyl group. A protein is a polymer in which at least 100 amino acid monomers are linked through bonds between an amino group and a carboxyl group.

67. 9.4 Reactions in CellsCarbon Chemistry 9.4 Reactions in Cells

68. Carbon ChemistryPhotosynthesis During photosynthesis, plants chemically combine carbon dioxide and water into carbohydrates. During photosynthesis, plants chemically combine carbon dioxide and water into carbohydrates. The process requires light and chlorophyll, a green pigment in plants. The process requires light and chlorophyll, a green pigment in plants.

69. 9.4 Reactions in CellsCarbon Chemistry During photosynthesis, energy from sunlight is converted into chemical energy. During photosynthesis, energy from sunlight is converted into chemical energy. 6H 2 O + 6CO 2 + light → C 6 H 12 O 6 + 6O 2

70. 9.4 Reactions in CellsCarbon Chemistry Cellular Respiration During cellular respiration, the energy stored in the product of photosynthesis is released. During cellular respiration, the energy stored in the product of photosynthesis is released. Cellular respiration is a complex series of reaction summarized by the equation Cellular respiration is a complex series of reaction summarized by the equation C 6 H 12 O 6 + 6O 2 → 6H 2 O + 6CO 2 + heat C 6 H 12 O 6 + 6O 2 → 6H 2 O + 6CO 2 + heat

71. 9.4 Reactions in CellsCarbon Chemistry Each process produces the reactants for the other process. Each process produces the reactants for the other process. Carbon dioxide and water are reactants in photosynthesis and the products of respiration. Carbon dioxide and water are reactants in photosynthesis and the products of respiration. Carbohydrates and oxygen are reactants in cellular respiration and products of photosynthesis. Carbohydrates and oxygen are reactants in cellular respiration and products of photosynthesis.

72. 9.4 Reactions in CellsCarbon Chemistry Photosynthesis and Cellular Respiration

73. 9.4 Reactions in CellsCarbon Chemistry Enzymes and Vitamins Enzymes and vitamins are compounds that help cells function efficiently at normal body temperatures. Enzymes and vitamins are compounds that help cells function efficiently at normal body temperatures. Enzymes are proteins that act as catalysts for reactions in cells. Enzymes are proteins that act as catalysts for reactions in cells.

74. 9.4 Reactions in CellsCarbon Chemistry Enzymes allow reactions to proceed faster at much lower temperatures than would normally happen. Enzymes allow reactions to proceed faster at much lower temperatures than would normally happen. Vitamins are organic compounds that organisms need in small amounts but cannot produce. Vitamins are organic compounds that organisms need in small amounts but cannot produce.