Carbon

1
Chapter 22

• Carbon Hydrocarbons

2
Chapter 22 Vocabulary

• Diamond
• Graphite
• Fullerenes
• Delocalized electrons
• Organic compounds
• Catenation
• Hydrocarbons
• Isomers
• Structural formula
• Structural isomers
• Geometric isomers

• Saturated hydrocarbon
• Alkanes
• Cycloalkanes
• Alkyl groups
• Natural gas
• Petroleum
• Unsaturated hydrocarbons
• Alkynes
• Aromatic hydrocarbons
• benzene

3
Chapter 22 Vocabulary

• Diamond is a colorless, crystalline, solid form
  of carbon
• Graphite is a soft, black, crystalline form of
  carbon that is a fair conductor of electricity
• Fullerenes are dark colored solids made of
  spherically networked carbon atom cages.
• Delocalized electrons are electrons shared by
  more than two atoms
• Organic compounds covalently bonded compounds
  containing carbon, excluding carbonates and
  oxides.
• Catenation the covalent bonding of an element to
  itself to form chains or rings.
• Hydrocarbons are composed of only carbon and
  hydrogen they are the simplest organic
  compounds.
• Compounds that have the same molecular formula
  but different structures are called isomers.
• Structural formula indicates the number and types
  of atoms present in a molecule and also shows the
  bonding arrangement of the atoms.

4
Chapter 22 Vocabulary

• Structural isomers are isomers in which the atoms
  are bonded together in different orders.
• Geometric isomers are isomers in which the order
  of atom bonding is the same but the arrangement
  of atoms in space is different.
• Saturated hydrocarbons are hydrocarbons in which
  each carbon atom in the molecule forms four
  single covalent bonds with other atoms.
• Hydrocarbons that contain only single bonds are
  alkanes.
• Cycloalkanes are alkanes in which the carbon
  atoms are arranged in a ring, or cyclic,
  structure.
• Alkyl groups are groups of atoms that are formed
  when one hydrogen atom is removed from an alkane
  molecule
• Natural gas is a fossil fuel composed primarily
  of alkanes containing one to four carbon atoms
• Petroleum is a complex mixture of different
  hydrocarbons that varies greatly in composition.
• Unsaturated hydrocarbons are hydrocarbons in
  which not all carbon atoms have four single
  covalent bonds.

5
Chapter 22 Vocabulary

• Structural isomers are isomers in which the atoms
  are bonded together in different orders.
• Geometric isomers are isomers in which the order
  of atom bonding is the same but the arrangement
  of atoms in space is different.
• Alkenes are hydrocarbons that contain double
  covalent bonds.
• Hydrocarbons with triple covalent bonds are
  alkynes.
• Aromatic hydrocarbons are hydrocarbons with six
  membered carbon rings and delocalized electrons
• Benzene is the primary aromatic hydrocarbon

6
Alkanes and Aromatic Hydrocarbons

• Organic Compounds
• Bonding in Hydrocarbons
• Naming Alkanes
• Properties of Alkanes

7
Organic Chemistry and Hydrocarbons

• _________ originally meant chemicals that came
  from ______________.
• 1828 German chemist Friedrich Wohler synthesized
  urea in a lab
• Today, organic chemistry is the chemistry of
  virtually all compounds containing the element
  ___________.

8
Friedrich Wohler 1800 1882 Used inorganic
substances to synthesize urea, a carbon compound
found in urine. This re-defined organic chemistry.
9
Organic Chemistry and Hydrocarbons

• Over a million organic compounds, with numerous
  properties
• Why so many? Carbons unique bonding ability!
• Lets start with the simplest of the organic
  compounds Hydrocarbons

10
Organic Compounds

• Contain _________________
• Have ______________ bonds
• Have low _____________ points
• Have low _______________ points
• Burn in air (oxygen)
• Are soluble in _____________ solvents
• Form large ________________

11
Alkanes

• Contain ______ and _________ only
• Contain ____________ bonds C-C
• Have _____ bonds to every carbon (C) atom
• Are ________________

12
Alkanes
Structural Formulas

• Show the bonds between each of the atoms
• H H
• ? ?
• H ? C ? H H C H
• ? ?
• H H
• CH4 - methane

13
Alkanes
Structural Formulas

• H H Condensed Structural
  Formulas
• H C C H CH3 CH3
• H H Ethane
• H H H
• H C C C H CH3 CH2 CH3
• H H H Propane

14
Alkanes
Structural Formulas

• H H H
• H C C C H
• H H H
• CH3 CH2 CH3
• CH3CH2CH3

Structural Formula
Condensed Structural Formula
Condensed Formula
15
Alkanes
Structural Formulas
Examples
Condensed__________________
_____________ formula
16
Alkanes
17
Organic Naming Prefixes
18
Naming Alkanes

• Name carbons Structural Formula
• ____ane 1 CH4
• ____ane 2 CH3CH3
• ____ane 3 CH3CH2CH3
• ____ane 4 CH3CH2CH2CH3
• ____ane 5 CH3CH2CH2CH2CH3

19
Naming Alkanes

• Name carbons Structural Formula
• ___ane 6
  CH3CH2CH2CH2CH2CH3
• ____ane 7 CH3CH2CH2CH2CH2CH2C
  H3
• ___ane 8 CH3CH2CH2CH2CH2CH2CH2CH3
  
• ___ane 9 CH3 CH2 CH2CH2CH2CH2CH2CH2CH3
• ___ane 10 CH3CH2CH2CH2CH2CH2CH2CH2CH2CH3

20
Practice Problems

• A. What is the condensed formula for
• H H H H
• H C C C C H
• H H H H
• B. What is its molecular formula?
• C. What is its name?

21
Reactions of Alkanes

• Combustion
• alkane O2 CO2 H2O heat

Combustion In the Cell

• Metabolic oxidation is combustion
• C6H12 O6 6O2 6CO2 6H2O heat
• glucose

22
Combustion Example

• Complete the combustion reaction for
• C3H8 O2
• Balance your equation

23
Practice Problem

• Complete and balance the reaction for the
  complete combustion of C7H16

24
Alkanes and Aromatic Hydrocarbons

• Branched Alkanes
• Structural Formulas

25
Alkyl Groups

• Branches on carbon chains
• H
• H C CH3 _________
• H
• H H
• H C C CH3CH2 _________
• H H

26
Alkyl Groups
27
Branched Alkanes

• CH3
• CH3CHCH3
• methyl groups
• CH3 CH3
• CH3CHCH2CHCH3

28
Naming Branched Alkanes

• CH3 methyl branch
• CH3CH2CH2CHCH2CH3
• 6 5 4 3 2 1 Count

29
Naming Branched Alkanes

• CH3 methyl branch
• CH3CH2CH2CHCH2CH3
• 6 5 4 3 2 1 Count
• 3-Methylhexane
• on third C CH3 six carbon chain
• group

30
Naming Alkanes
31
Naming Alkanes Example
32
Naming Practice Problems

• A. CH3 CH3
• CH3CHCH2CHCH3
• B. CH3 CH3
• CH3CH2CHCH2CCH2CH3
• CH3

33
Practice Problems

• Write a condensed structure for
• A. 3,4-dimethylheptane
• B. 2,2-dimethyloctane

34
Isomers

• Same _____________ formula
• Same ________ and ______ of atoms
• Different ________________ of atoms
• Also have different properties, such as b.p.,
  m.p., and reactivity

35
Structural Isomers
___________________ are isomers in which the
atoms are bonded together in different orders.
36
Geometric Isomers

• ____________________ are isomers in which the
  order of atom bonding is the same but the
  arrangement of atoms in space is different.

37
Examples of Isomers

• The formula C4H10 has two different structures
• CH3
• CH3CH2CH2CH3 CH3CHCH3
• Butane 2-methylpropane
• When a CH3 is is used to form a branch, it makes
  a new isomer of C4H10.

38
Practice Problem

• Write 3 isomers of C5H12 and name each.

39
Practice Problems

• Write the structural formulas of 3 isomers that
  have the formula C5H12. Name each.

40
Alkanes and Aromatic Hydrocarbons

• Cycloalkanes
• Aromatic Hydrocarbons

41
Cycloalkanes

• _____________ CH2
• CH2 CH2
• _____________ CH2 CH2
• CH2 CH2

42
More Cycloalkanes

• ____________ CH2
• CH2 CH2
• CH2 CH2
• ____________
• CH2
• CH2 CH2
• CH2 CH2
• CH2

43
Naming Cycloalkanes with Side Groups

• Number of Naming
• side groups
• One Side group name goes in front of the
  cycloalkane name.
• Two or more Number the ring in the direction
  that gives the lowest numbers to the side
  groups.

44
Cycloalkanes with Side Groups
45
Practice Problems
46
Aromatic Compounds and Benzene

• ___________________ contain __________.
• Benzene, C6H6 , is represented as a ______
  carbon ring with _____ double bonds.
• Two possible can be drawn to show benzene in
  this form.

47
Benzene Structure

• The structures for ______________ can also be
  written as a single structure where the
  alternating double bonds are written as a circle
  within the ring.
• Benzene
• structure

48
Aromatic Compounds in Nature and Health

• Many aromatic compounds are common in
  _____________ and in _____________.

49
Naming Aromatic Compounds

• Aromatic compounds are named with benzene as the
  parent chain. One side group is named in front of
  the name benzene.
• methylbenzene chlorobenzene
• (toluene)

50
Naming Aromatic Compounds

• When two groups are attached to benzene, the
  ring is numbered to give the lower numbers to the
  side groups. The prefixes ortho (1,2), meta
  (1,3-) and para (1,4-) are also used.

51
Some Common Names

• Some substituted benzene rings also use a common
  name. Then naming with additional more side
  groups uses the ortho-, meta-, para- system.

52
Practice Problems

• Write the structural formulas for each of the
  following
• A. 1,3-dichlorobenzene
• B. Ortho-chlorotoluene

53
Practice Problems

• Select the names for each structure
• 1. Chlorocyclohexane
• 2. Chlorobenzene
• 3. 1-chlorobenzene
• 1. Meta-methyltoluene
• 2. Meta-dimethylbenzene
• 3. 1,3-dimethylbenzene

54
Haloalkanes, Alkenes, and Alkynes

• Alkenes and Alkynes

55
Saturated and Unsaturated Compounds

• Saturated compounds (alkanes) have the maximum
  number of hydrogen atoms attached to each carbon
  atom
• Unsaturated compounds have fewer hydrogen atoms
  attached to the carbon chain than alkanes
• Unsaturated compounds contain double or triple
  bonds alkenes alkynes

56
Alkenes

• Carbon-carbon _____________ bonds
• Names end in -___________
• H2CCH2 ethene (ethylene)
• H2CCH-CH3 propene (propylene)
• cyclohexene

57
Alkenes
58
Alkynes

• Carbon-carbon __________ bonds
• Names end in -_________
• HC?CH ethyne(acetylene)
• HC?C-CH3 propyne

59
Naming Alkenes and Alkynes

• When the carbon chain has 4 or more C atoms,
  number the chain to give the lowest number to
  the double or triple bond.
• 1 2 3 4
• CH2CHCH2CH3 1-butene
• CH3CHCHCH3 2-butene
• CH3CH?CHCH3 2-butyne

60
Naming Alkenes
Slide 35
61
Naming Alkenes
62
Naming Alkynes
Slide 35
63
Practice Problem

• Write the names for each of the following
  unsaturated compounds
• A. CH3CH2C?CCH3
• CH3
• B. CH3CCHCH3 C.

64
Hydrogenation

• Adds a hydrogen atom to each carbon atom of a
  double bond
• H H H H
• Ni
• HCCH H2 HCCH
• H H
• ethene ethane

65
Products of Hydrogenation

• Adding H2 to vegetable oils produces compounds
  with higher melting points
• Margarines
• Soft margarines
• Shortenings (solid)

66
Trans Fats

• In the US, it is estimated that 2-4 of our total
  Calories is in the form of trans fatty acid.
• trans fatty acids behave like saturated fatty
  acids in the body.
• Several studies reported that trans fatty acids
  raise LDL-cholesterol. Some studies also report
  that trans fatty acid lower HDL-cholesterol
• The trans fatty acids controversy will continue
  to be debated.

67
Unsaturated Fatty Acids

• Fatty acids in vegetable oils are omega-6 acids
  (the first double bond occurs at carbon 6
  counting from the methyl group)
• A common omega-6 acid is linoleic acid
• CH3CH2CH2CH2CH2CHCHCH2CHCH(CH2)7COOH
• 6
• linoleic acid, a fatty acid

68
Trans Fats

• In vegetable oils, the unsaturated fats usually
  contain cis double bonds.
• During hydrogenation, some cis double bonds are
  converted to trans double bonds (more stable)
  causing a change in the fatty acid structure
• If a label states partially or fully
  hydrogenated, the fats contain trans fatty
  acids.

69
Fats and Atheroschlerosis

• Inuit people of Alaska have a high fat diet and
  high blood cholesterol levels, but a very low
  occurrence of atherosclerosis and heart attacks.
• Fat in the Intuit diet was primarily from fish
  such as salmon, tuna and herring rather than from
  land animals (as in the American diet).

70
Omega-3 Fatty Acids

• Fatty acids in the fish oils are mostly the
  omega-3 type (first double bond occurs at the
  third carbon counting from the methyl group).
• linolenic acid 18 carbon atoms
• CH3CH2CHCHCH2CHCHCH2CHCH(CH2)7COOH
• ?
• eicosapentaenoic acid (EPA) 20 carbon atoms
  CH3CH2(CHCHCH2)5(CH2)2COOH

71
Atherosclerosis

• Plaques of cholesterol adhere to the walls of the
  blood vessels
• Blood pressure rises as blood squeezes through
  smaller blood vessels
• Blood clots may form
• Omega-3 fatty acids decrease the sticking of
  blood platelets (fewer blood clots)
• Omega-3 fatty acids can increase bleeding time

72
Questions

• (1) Ture or (2) False
• A. ____ There are more unsaturated fats in
  vegetable oils.
• B. ____ Vegetable oils have more omega-3 oils
  than found in fish.
• C. ____ Hydrogenation of oils converts some
  cis-double bonds to trans- double bonds.
• D. ____ Animal fats have more saturated fats.

73
Natural Gas

• Fossil fuels provide much of the worlds energy
• Natural gas and petroleum contain mostly the
  aliphatic (or straight-chain) hydrocarbons
  formed from marine life buried in sediment of the
  oceans
• Natural gas is an important source of alkanes of
  low molecular mass

74
Natural Gas

• Natural gas is typically
• 80 methane, 10 ethane, 4 propane, and 2
  butane with the remainder being nitrogen and
  higher molar mass hydrocarbons
• also contains a small amount of He, and is one of
  its major sources

75
Natural Gas

• Natural gas is prized for combustion, because
  with adequate oxygen, it burns with a hot, clean
  blue flame
• CH4 2O2 ? CO2 2H2O heat
• Incomplete burning has a yellow flame, due to
  glowing carbon parts, as well as making carbon
  monoxide

76
Petroleum

• The compounds found in petroleum (or crude oil)
  are more complex than those in natural gas
• Usually straight-chain and branched-chain
  alkanes, with some aromatic compounds also
• Crude oil must be refined (separated) before
  being used

77
Petroleum

• It is separated by distillation into fractions,
  according to boiling pt.
• Fractions containing higher molar mass can be
  cracked into more useful shorter chain
  components, such as gasoline and kerosene
• involves catalyst and heat
• starts materials for plastics and paints

78
Citations

• http//www.karentimberlake.com/
• http//www.cottonchemistry.bizland.com/chem/chemno
  tes1.htm