Organic Chemistry

1
Organic Chemistry
Alcohols Aldehydes and Ketones Carboxylic
Acids Esters Polymers
Saturated Hydrocarbons Petroleum Reactions of
Alkanes Unsaturated Hydrocarbons Aromatic
Hydrocarbons
2
Saturated Hydrocarbons

• Hydrocarbons are molecules of carbon and
  hydrogen, like methane.
• Methane
• Formula CH4

- When carbon has four bonds, it has a
tetrahedral arrangement.
3
Saturated Hydrocarbons

• Alkanes are hydrocarbons with only single bonds.
• A straight-chain alkane has a long chain of
  carbons bonded to each other with hydrogen atoms
  around the outside.
• Example propane has three carbon atoms and 8
  hydrogen atoms

4
Saturated Hydrocarbons

• Formulas For each carbon that is added in an
  alkane, there are two more hydrogen atoms in the
  compound.
• A CH2 group is added from one compound in the
  series to the next.
• CH3 (CH2) m CH3
• Memorize the first ten prefixes for naming
  alkanes meth, eth, prop, but, pent, hex, hept,
  oct, non, dec

5
Saturated Hydrocarbons

• Branched-Chain Alkanes
• A substituent is an atom or group that attaches
  to a carbon.
• Name alkyl groups by removing -ane and adding
  -yl
• Methyl group CH3
• An alkane substituent is an alkyl group.
• A chain with one or more substituent is branched.

6
Saturated Hydrocarbons

• Naming alkanes with the IUPAC rules.
• Step 1. Find the longest continuous chain of
  carbons (it doesnt have to be straight). (Draw
  a line through these carbons if its helpful.)
  Assign an alkane name according to the number
  of carbons in this chain.
•  

7
Saturated Hydrocarbons

• Step 2. All carbons not in this main chain are
  branches connected to the main chain. Name
  each branch using the corresponding prefix with a
  yl ending.
• 1 carbon - methyl
• 2 carbons - ethyl
• 3 carbons - propyl
•  

8
Saturated Hydrocarbons

• Step 3. Number the carbons in the main chain so
  that the branch(es) have the lowest possible
  numbers assigned to them. Assign each branch a
  number corresponding to where it attaches to the
  main chain.

2, 2, 3 trimethyl pentane
9
Petroleum

• Petroleum and natural gas were formed from
  decayed plants over 500 million years old.
• It is called buried sunshine because the energy
  in it originally came from the sun.
• Plants used photosynthesis to store energy.
• Petroleum contains hydrocarbons with chains
  containing 5-25 carbon atoms.
• Natural gas contains methane,
• ethane, propane and butane.

10
Combustion Reactions

• In a combustion reaction, a hydrocarbon (or
  another fuel) reacts with O2 to make CO2 and H2O.
• 2C4H10 13O2 ? 8CO2 10H2O

11
Combustion Reactions

• Write the balanced equation for the combustion of
  propane
• C3H8 ?
• 1. Write O2 on the left
• 2. Write CO2 and H2O on the right.
• 3. Balance.

CO2
H2O
O2
5
3
4
12
Substitution Reactions

• In substitution reactions, hydrogen atoms are
  replaced by different atoms.
• CH4 Cl2 CH3Cl HCl
• The hv represents ultraviolet radiation.

hv
13
Dehydrogenation Reactions

• In a dehydrogenation reaction, hydrogen atoms are
  removed and a double or triple bond forms.
• CH3CH3
  H2

Cr2O3
500 C
14
Unsaturated Hydrocarbons

• Alkenes have double bonds.
• Naming add -ene
• Example ethene

15
Unsaturated Hydrocarbons

• Naming alkenes Name them like alkanes, but use a
  number to show the location of the double bond.
• Because theres only one place for the double
  bond on ethene and propene, you dont need a
  number.
• Example 2-butene

16
Unsaturated Hydrocarbons

• Alkynes have triple bonds.
• Naming add -yne
• Example C2H2 ethyne

CH
CH
17
Unsaturated Hydrocarbons

• In addition reactions, atoms are added across a
  double or triple bond.
• Hydrogenation is an addition reaction. H2 is
  added.
• Halogenation is an addition reaction. A halogen
  (group 7A) is added.

Pt Catalyst
H2 CH3CH2CH3
Br2
18
Aromatic Hydrocarbons

• Aromatic hydrocarbons smell nice, like
  wintergreen and cinnamon.
• Most aromatic hydrocarbons contain a benzene
  ring.
• Benzene is a 6-carbon
• ring with three double
• bonds (C6H6).

H
H
C
H
C
C
C
C
H
H
C
H
19
Aromatic Hydrocarbons

• When two or more structures can be drawn for a
  molecule, resonance occurs.

20
Aromatic Hydrocarbons

• In reality, there are no double bonds in benzene.
  The electrons are shared evenly around the ring.
• This is a more accurate way to represent benzene

21
Aromatic Hydrocarbons

• Benzene is called a phenyl group when it is a
  side group on an alkane.
• Example 3-phenylnonane

22
Aromatic Hydrocarbons

• Naming benzene with one side group Benzene
  Side group name
• Example Methylbenzene

23
Aromatic Hydrocarbons

• Naming benzene with two side groups Name them
  like alkanes, but assign one group the 1
• Example 1,3-dimethyl benzene

24
Aromatic Hydrocarbons

• Common names for disubstituted benzenes
• 1, 2 position is orotho (o)
• 1, 3 position is meta (m)
• 1, 4 position is para (p)

Systematic Name Common Name
1, 2-dichlorobenzene o-dichlorobenzene
1, 3-dichlorobenzene m-dichlorobenzene
1, 4-dichlorobenzene p-dichlorobenzene
25
Alcohols

• Functional groups are groups of atoms that are
  capable of characteristic chemical reactions.
• For example, the functional group of a carboxylic
  acid is circled below, a COOH group.
• The R stands for the rest of the molecule.

26
Alcohols

• An alcohol is an organic compound with an -OH
  group.
• The -OH group is called a hydroxyl group.
• There are three kinds of alcohols
• 1). Primary alcohol one R group attached to
  the C-OH
• 2). Secondary alcohol twoR groups attached
  to the C-OH
• 3). Tertiary alcohol three R groups
  attached to the C-OH

27
Alcohols

• Primary
• Secondary
• Tertiary

28
Alcohols

• Naming alcohols Drop the e from the alkane
  name and -ol
• Example Methanol.

29
Alcohols

• Properties
• Ethanol is produced by fermentation, which is the
  digestion of sugar by yeast. Alcoholic beverages
  such as beer are made by this process.
• Methanol is used to make many materialsplastics,
  fibers, etc.

30
Aldehydes and Ketones

• A carbonyl group is a functional group with a
  group.
• An aldehyde has a carbonyl group, where the
  carbon is bonded to one or two hydrogen atoms.
  It has the general formula RCHO.

31
Aldehydes and Ketones

• A keytone has a carbonyl group on a carbon that
  is bonded to two other carbons. General formula
  RCOR

32
Aldehydes and Ketones

• IUPAC Naming
• Aldehydes alkane name minus e plus al
• Methane ? Methanal
• Keytones alkane name minus e plus anone.
  Write the number of the carbon that has the
  carbonyl group first
• 2-pentanone

33
Carboxylic Acids

• Carboxylic acids have the general formula RCOOH
• They ionize slightly when dissolved in water

34
Carboxylic Acids

• IUPAC Naming
• Add -oic acid
• Ethanoic acid
• Carboxylic acids dont smell good.
• Vinegar contains ethanoic acid.

35
Esters

• Esters
• Esters have the general formula RCOOR

36
Esters

• Esters can be made by a reaction between a
  carboxylic acid and alcohol.
• Esters smell good, and make the smells in
  bananas, oranges and other fruits and flowers.

Methyl ethanoate
H
o
o
H
H
H
C
H
H O

C
H
C
C
H
O H
O H
O
C
C
H
H
H
H
H
H
37
Polymers

• Polymers are made from small molecules, called
  monomers.
• Ethene can react with itself, creating an
  addition polymer.
• This reaction is called an addition reaction.
  Many ethene add onto the growinig polymer chain
  to make a very long molecule.

38
Polymers
Ethene Growing polymer chain
Polyethylene