1. Chapter 10 Introduction to Organic Chemistry: Alkanes
10.1
Organic Compounds

2. Organic Chemistry An organic compound
is a compound made from carbon atoms
has one or more C atoms
has many H atoms
may also contain O, S, N, and halogens
usually has carbon written first

3. Organic Compounds Typical organic compounds have covalent bonds
have low melting points
have low boiling points
are flammable
are soluble in nonpolar solvents
are not soluble in water
Vegetable oil is an organic compound
and not soluble in water.

4. Organic vs. Inorganic
Propane, C3H8, is an organic compound used as a fuel.
NaCl, salt, is an inorganic compound composed of Na+ and Cl ions.
Why is propane organic,
but NaCl is not?

5. Comparing Organic and Inorganic Compounds

6. Learning Check
Identify each characteristic as most typical of compounds that are inorganic or organic. A. Has a high melting point B. Is not soluble in water C. Has the formula CH3CH2CH3 D. Has the formula MgCl2 E. Burns easily in air F. Has covalent bonds

7. Solution
Identify each characteristic as most typical of compounds that are inorganic or organic. A. Has a high melting point inorganic B. Is not soluble in water organic C. Has the formula CH3CH2CH3 organic D. Has the formula MgCl2 inorganic E. Burns easily in air organic F. Has covalent bonds organic

8. Bonding in Organic Compounds
carbon has 4 valence electrons and hydrogen has 1
carbon achieves an octet by forming four bonds, with each line representing 2 electrons
CH4, methane

9. Tetrahedral Structure of Carbon CH4
VSEPR theory predicts that a carbon atom with four single, covalent bonds has a tetrahedral shape.
Methane is represented using different models: (a) tetrahedron, (b) ball-and- stick model, (c) space-filling model, (d) expanded structural formula.

10. Tetrahedral Structure of Carbon C2H6
In ethane,
each carbon forms covalent bonds to another carbon and three hydrogen atoms
each carbon atom retains its tetrahedral shape
Ethane, CH3─CH3

11. Tetrahedral Structure of Carbon C2H6
In molecules with two or more carbon atoms, each carbon atom with four single bonds has a tetrahedral shape.
Representations of ethane: (a) tetrahedral shape of each carbon, (b) ball-and-stick model, (c) space-filling model, (d) expanded structural formula.

12. Learning Check
In the butane molecule, C4H10, predict the shape around each carbon atom.

13. Solution
In the butane molecule, C4H10, predict the shape around each carbon atom.
Each carbon atom has four single covalent bonds and therefore a tetrahedral shape.

14. Chapter 10 Introduction to Organic Chemistry: Alkanes
10.2
Alkanes

15. Alkanes Alkanes are organic molecules
containing primarily C–C single bonds
commonly used as fuels for heaters and cooktops
whose names end in ane
named by using the number of carbon atoms connected in a continuous chain

16. IUPAC Naming of the First Ten Alkanes

17. Condensed Structural Formulas
In a condensed structural formula,
each carbon atom and its attached hydrogen atoms are written as a group
a subscript indicates the number of hydrogen atoms bonded to each carbon atom
of butane, four carbon atoms are attached in a straight line
CH3CH2CH2CH butane

18. Condensed Structural Formulas
Alkanes are written with structural formulas that are
expanded to show each bond
condensed to show each carbon atom and its attached hydrogen atoms
Expanded Condensed Expanded Condensed

19. Writing Structural Formulas
Carbon atoms in a chain
maintain tetrahedral shape
are connected in a zigzag pattern
are drawn as two-dimensional
can be written in several conformations

20. Expanded, Condensed, and Skeletal Structures
A hexane molecule can
be represented in several ways:
a molecular formula
a ball-and-stick model
an expanded structural formula
a condensed structural formula
a skeletal formula

21. Expanded, Condensed, and Skeletal Structures for C4H10

22. Learning Check
1. Write the expanded structural formula for the following: 2. What is its molecular formula? 3. What is its condensed structural formula? 4. What is its name?

23. Solution
1. Write the expanded structural formula for the following: 2. What is its molecular formula? C5H12 3. What is its condensed structural formula? CH3CH2CH2CH2CH3 4. What is its name? pentane

24. Learning Check
Write the condensed structural formula for A. ethane B. heptane

25. Solution
Write the condensed structural formula for A. ethane CH3CH3 B. heptane CH3CH2CH2CH2CH2CH2CH3

26. Cycloalkanes Cycloalkanes are cyclic alkanes
have two less hydrogen atoms than the open chain
are named by using the prefix cyclo before the name of the alkane chain with the same number of carbon atoms
propane, C3H8 cyclopropane, C3H6

27. Formulas of Cycloalkanes

28. Learning Check
Give the IUPAC name for each of the following compounds: A. B.

29. Solution Give the IUPAC name for each of the following compounds: A.
An alkane with eight continuous carbon atoms is octane.
B A cyclic molecule with five carbons is
cyclopentane.

30. Learning Check
Name the following alkanes: A. CH3CH2CH2CH3 B. C. CH3CH2CH2CH2CH2CH2CH2CH3 D.

31. Solution
Name the following alkanes: A. CH3CH2CH2CH3 butane B. cyclopropane C. CH3CH2CH2CH2CH2CH2CH2CH3 octane D. cyclohexane

32. Chapter 10 Introduction to Organic Chemistry: Alkanes
10.3
Alkanes with Substituents

33. Isomers of Butane Isomers
have the same molecular formula with different atom arrangements
of butane (C4H10) are a straight chain and a branched chain
The isomers of butane have the same number and type of atoms, but the atoms are bonded in a different order.

34. Substituents and Alkyl Groups
Substituents are atoms or groups of atoms attached to the
carbon chain and include alkyl and halo groups.
Alkyl groups are
carbon branches attached to carbon chains
named with a yl ending
Halo substituents are
halogens attached to the carbon chain
named as fluoro, chloro, bromo, or iodo

35. Substituents and Alkyl Groups

36. Guide to Naming Alkanes with Substituents

37. Write IUPAC Names for Alkanes with Substituents
Give the IUPAC name for the following compound: Step 1 Write the alkane name of the longest chain of carbon atoms. The longest chain has five carbons, pentane.

38. Write IUPAC Names for Alkanes with Substituents
Step 2 Number the carbon atoms starting from the end nearer a substituent. Step 3 Give the location and name of each substituent (in alphabetical order) as a prefix to the name of the main chain. 2-chloro-3-methylpentane

39. Learning Check
Give the IUPAC name for the following compound:

40. Solution
Give the IUPAC name for the following compound: Step 1 Write the alkane name of the longest chain of carbon atoms. The longest chain has four carbons, butane.

41. Solution
Step 2 Number the carbon atoms starting from the end nearer a substituent. Step 3 Give the location and name of each substituent (in alphabetical order) as a prefix to the name of the main chain. 1,2-dibromo-3-methylbutane

42. Naming Cycloalkanes with Substituents
Give the IUPAC name for the following cycloalkane. Step 1 Write the alkane name of the longest chain of carbon atoms. The longest chain is a six-member ring, cyclohexane.

43. Solution
Step 2 Number the carbon atoms starting from the end nearer a substituent. Step 3 Give the location and name of each substituent (in alphabetical order) as a prefix to the name of the main chain. For cycloalkanes with just one substituent, there is no need to give the location of the substituent: ethylcyclohexane

44. Drawing Formulas for Alkanes
Draw the structure for 1-chloro-1,2-dimethylheptane
heptane – 7-carbon chain
methyl group on carbon 1 and 2
chlorine on carbon 1

45. Guide to Drawing Formulas for Alkanes

46. Learning Check
Draw the condensed structural formula for 3-bromo-1-chlorobutane.

47. Solution
Draw the condensed structural formula for 3-bromo-1-chlorobutane. Step 1 Draw the main chain of carbon atoms. The longest chain in butane has four carbon atoms. CCCC Step 2 Number chain and place the substituents on the carbons indicated by the numbers bromo: Br goes on carbon 3. CCCC Cl Br 1-chloro: Cl goes on carbon 1.

48. Solution
Draw the condensed structural formula for 3-bromo-1-chlorobutane. Step 3 Add hydrogen to complete four bonds to each carbon. CH2CH2CHCH3   Cl Br 3-bromo-1-chlorobutane

49. Learning Check
Name each of the following cycloalkanes. A. B. C.

50. Solution Name each of the following cycloalkanes.
A. methylcyclopropane
B ethylcyclobutane
C. chlorocyclopentane

51. Chapter 10 Introduction to Organic Chemistry: Alkanes
10.4
Properties of Alkanes

52. Some Uses of Alkanes
Alkanes with one to four carbons are gases at room temperature and are widely used as heating fuels.
methane, ethane, propane, butane
Butane has four carbons:
Alkanes with five to eight carbons are highly volatile liquids at room temperature, making them useful in fuels such as gasoline.
pentane, hexane, heptane, octane
Octane has eight carbons:

53. Some Uses of Alkanes
Alkanes with 9−17 carbons are liquids with higher boiling points and are found in motor oils, mineral oil, kerosene, diesel, and jet fuels.
Decane has 10 carbons:

54. Some Uses of Alkanes Alkanes with 18 or more carbon atoms
have high molar masses
are waxy solids at room temperature
are used in waxy coatings of fruits and vegetables

55. Solubility and Density of Alkanes
Alkanes are
nonpolar
insoluble in water
less dense than water
flammable in air
The crude oil in oil spills floats on top of the water, forming a thin layer on the surface because it is less dense than water.

56. Combustion of Alkanes Alkanes have strong CC bonds
react with oxygen gas to make carbon dioxide and water in combustion reactions
release energy when CC bonds are broken in combustion reactions
CH4(g) + 2O2(g)  CO2(g) + 2H2O(g) + energy

57. Alkane Mixtures in Crude Oil
An oil refinery turns crude oil into usable fuel, producing natural gas, gasoline, kerosene, lubricant oils, and asphalt.

58. Alkane Mixtures in Crude Oil

59. Learning Check
Propane is a fuel often used in barbeques. Write a balanced equation for the complete combustion of propane.

60. Solution
Unbalanced equation: C3H8 + O2 CO2 + H2O Balance C: C3H8 + O2 3CO2 + H2O Balance H: C3H8 + O2 3CO2 + 4H2O Balance O: C3H8 + 5O2 3CO2 + 4H2O (balanced)

61. Chapter 10 Introduction to Organic Chemistry: Alkanes
10.5
Functional Groups

62. Elements in Organic Compounds
In organic molecules, carbon atoms bond
with four bonds
mostly with H and other C atoms
sometimes to O, N, S
sometimes to halogens F, Cl, and Br

63. Elements in Organic Compounds

64. Functional Groups Functional groups are
a characteristic feature of organic molecules that behave in a predictable way
composed of an atom or group of atoms
groups that replace a hydrogen atom in the corresponding alkane
a way to classify families of organic compounds

65. Alkenes, Alkynes, and Aromatic Compounds
Alkenes contain a double bond between adjacent carbon atoms.
Alkynes contain a triple bond.
Aromatic compounds contain a ring of six carbon atoms called benzene.

66. Comparing Alkenes, Alkynes, and Aromatic Compounds

67. Learning Check
Identify the following compounds as an alkene, alkyne, or aromatic compound. A. B. C.

68. Solution
Identify the following compounds as an alkene, alkyne or aromatic compound.
A. aromatic
B. alkene
C. alkyne

69. Alcohols, Thiols, and Ethers
An alcohol contains the hydroxyl (−OH) functional group. A thiol contains the thiol (−SH) functional group. An ether contains an oxygen atom bonded to two carbon atoms (COC) functional group.

70. Aldehydes and Ketones
An aldehyde contains a carbonyl group (C=O), which is a carbon atom with a double bond to an oxygen atom. The carbonyl carbon is attached to a hydrogen. In a ketone, the carbon of the carbonyl group (C=O) is attached to two carbon atoms.

71. Carboxylic Acids and Esters
Carboxylic acids contain the carboxyl group, which is a carbonyl group attached to a hydroxyl group. COOH An ester contains the carboxyl group between carbon atoms. COOCH3

72. Amines Amines have a functional group that contains a nitrogen atom
are derivatives of ammonia, NH3, in which one, two, or three hydrogen atoms are replaced with carbons

73. Amides
Amides
have an amine group instead of an OH group on the carbonyl carbon
are an important biological functional group, the
simplest amide
being urea

74. Classification of Organic Compounds

75. Learning Check
Classify each of the following as an alcohol, ether, aldehyde, ketone, carboxylic acid, ester, amine, or amide. A. B. C. D. E.

76. Solution
Classify each of the following as an alcohol, ether, aldehyde, ketone, carboxylic acid, ester, amine, or amide. A. B. C. D. E.
alcohol
ether
amine
carboxylic acid
ester

77. Concept Map – Organic Compounds