Organic Chemistry : Ch. 9
Organic chemistry is the
branch of chemistry which
deals with “carbon based”
Carbon is an element
which has the unique
ability to bond long chains,
rings, and react with other
elements to form a variety
Carbon compounds are
found in many forms :
gases, aqueous, and solids.
Carbon is recycled in
nature by the carbon cycle.
Carbon chains can be
modified by reactions to
form different type of
carbon based (organic)
Story of Carbon
Carbon is a major component
of living things.
Lipids (fats and oils), sugars,
starches, proteins, DNA, etc.
are composed of carbon,
hydrogen, oxygen, nitrogen,
and other atoms.
Lipids, sugars, and starches
are composed of carbon,
hydrogen, and oxygen.
Proteins are composed of
carbon, hydrogen, oxygen,
nitrogen, and sometimes
Story of Carbon
Some carbon compounds are not considered organic.
Oxides of carbon (CO2 , CO )
Ionic compounds of carbon like carbonate, cyanide ions and
carbides where carbon behaves like a negative ion.
Sodium carbonate, hydrogen cyanide, calcium carbide
Story of Carbon
When the oxygen,
nitrogen, sulfur, and other
atoms are removed by
bacteria, what is left is a
hydrocarbon ( Carbon and
These hydrocarbons are of
mixed sizes, and are known
as “crude oil” when
recovered from the earth. Hydrocarbons : C & H atoms
Story of Carbon
Carbon atoms have four
electrons in their outer
energy level, and will want
to covalently bond (share
electrons) with itself and
other atoms to form more
stable chain and ring
The crude oil contains a
mixture of hydrocarbons
including : butane(lighter
fluid), gasoline, diesel,
candle wax, etc.
Story of Carbon
The hydrocarbons found in
crude oil can be separated
based upon their boiling
points and refined or
By adding substances to
them a host of other
organic compounds can be
produced : (alcohols,
esters, ethers, plastic,
Hydrocarbons are a class of organic compounds
which contain only carbon and hydrogen.
Hydrocarbons are characterized as carbon chains,
branched chains, and rings.
Fossil Fuels are primary sources of hydrocarbons.
These include Natural Gas, Crude Oil, Heavy Oil, Oil
Sands, and Coal.
Refining is the process that separates and purifies
Carbon has 4 valence electrons and will form 4
covalent bonds with hydrogen. A line between
carbon and another atom represents the sharing of 2
electrons. Therefore every carbon in an organic
compound needs 4 lines around it.
Hydrocarbons with all single carbon bonds are
described as the Alkanes.
Families of Organic
Organic compounds can be grouped into families by
their common structural features
We shall survey the nature of the compounds in a tour
of the families in this unit.
This basic family or series for hydrocarbons are the
alkanes, compounds that contain only carbons and
hydrogens, all connected exclusively by single bonds
The chains of carbons can be rearranged to form
different shapes with the same number and kinds of
atoms. These are called isomers.
Alkanes and Alkane Isomers
Alkanes: Compounds with C-C single bonds and C-H bonds
only (no functional groups)
Connecting carbons can lead to large or small molecules
The formula for an alkane with no rings in it must be CnH2n+2
where the number of C’s is n
Alkanes are saturated with hydrogen (no more can be added
They are also called aliphatic compounds
The name for an alkane is based on Greek root with
the suffix –ane.
Hydrocarbons come in a variety of forms.
Not all hydrocarbons are linear, some are branched and some are
Branched hydrocarbons have a carbon “backbone” with “groups”
attached to this backbone.
To name these compounds you need to follow the basic rules
Find the longest carbon chain (backbone) and write its
Identify the groups attached to this chain.
Assign the carbons in the chain numbers, which make the “group”
have the lowest number.
Identify any double or triple bonds with the corresponding carbon
Branched hydrocarbons are
found in crude oil and can
also by synthesized by
Hydrocarbons with only
single bonds are termed
Hydrocarbons with a
double or triple bond are
called “unsaturated” Saturated hydrocarbon : Pentane
For branched hydrocarbons use the longest
continuous chain for the root name.
Alkanes missing one H atom can have another
hydrocarbon attached at the missing H point.
Specify the names of groups by numbering the
C atoms starting at the end closest to the
attached to the
main chain are
here are the
If a group occurs more than once use a prefix to
show this. The numbers show the carbon where
the group is attached. Use commas and dashes.
Diagram the following branched hydrocarbons:
a) 2 methyl, hexane b) 2,2, dimethyl pentane
c) 2,3 dimethyl octane d) 2,4 dimethyl 3-decene
Cycloalkanes are alkanes that have carbon atoms that
form a ring (called alicyclic compounds)
Simple cycloalkanes rings of CH2 units, (CH2)n, or
Structure is shown as a regular polygon with the number of
vertices equal to the number of C’s (a projection of the
cyclopropane cyclobutane cyclohexane
Count the number of carbon atoms in the ring and the number in the
largest substituent chain. If the number of carbon atoms in the ring is
equal to or greater than the number in the substituent, the compound is
named as an alkyl-substituted cycloalkane
For an alkyl- or halo-substituted cycloalkane, start at a point of
attachment as C1 and number the groups on the ring so that the second
substituent has as low a number as possible.
Number the substituents and write the name
See text for more details and examples
You can use structural formulas as usual or
condensed formulas or line formulas.
6 4 2
Why is the above numbered incorrectly? What are their names?
Hydrocarbons : Alkenes
Carbon atoms have the ability to bond with other
atoms with single, double, or even triple bonds.
When carbon bonds to another carbon with a
double bond, and only carbon and hydrogen atoms
are in a compound it’s termed an alkene.
Ethylene(ethene) is the simplest alkene.
Alkynes are hydrocarbons which contain a triple
bond between carbons.
Alkynes end in “yne”.
Ethyne, Propyne, Butyne, etc.
Diagram the following hydrocarbons:
a) Propene b) Butyne
c) 2 hexene d) 2 - octyne
Diagram the following hydrocarbons :
a) Butane b) 2-methyl propane
• The molecular formula for both of these is C4H10
• Even though the formula is the same the properties of these
compounds is very different.
• This is an example of isomers. Isomers are compounds with the
same formula but different chemical and physical properties.
(Boiling point, etc…)
Diagram a pentane molecule, and two isomers of
this molecule. Name each isomer.
Hydrocarbons can also
form ring structures.
The simplest would be
When six carbons form a
ring we enter a new class
of hydrocarbons called
Benzene is the first
member of aromatic
occurs when two or more equally valid
structures can be drawn for a molecule
benzene exhibits resonance
• explains unique properties of benzene
and other aromatics
– benzene is perfectly flat (electrons are
delocalized, in other words, they are not
fixed to one carbon but can move around)
– bending or twisting of the aromatic
molecule would disrupt the electron
sharing and the stability of the molecule
Properties of Benzene
Molecular formula of benzene, C6H6, is based on its
percent composition and molar mass
MPbenzene = 5.5°C, BPbenzene=80.1°C
Very unreactive with halogens
Does not undergo addition reactions.
All carbon-to-carbon bonds in benzene are the same
length (determined by x-ray diffraction)
Empirical evidence shows that all carbons are
identical and that each carbon is bonded to one
1. Number the carbons around the ring to give
branches the lowest number possible.
2. Name the branches and end with the parent
3. If benzene is a branch, use the prefix
CH3 CH2 CH2 CH CH CH3
At this point we’ve concluded our study of hydrocarbons.
Below is a summary of the hydrocarbon compounds we’ve
Branched alkanes, alkenes, alkynes
Hydrocarbons are used to synthesize a large amount
of different organic compounds.
In addition some of these organic compounds are
naturally produced in living things.
By adding substances and breaking bonds the
hydrocarbon can become a new “class” of organic
The organic compounds we will study include:
Alcohols * sugars
Aldehydes * starches
Amine’s * lipids
Carboxylic Acids (Organic Acids)
Esters * proteins
Boiling points are
used to separate the
The smaller the
further it travels up
can go to the
Catalytic cracker. The
feedstock of long-chain
hydrocarbons (1) is mixed with
hot catalyst (2) and vaporized.
The vapor/powder mixture is
carried to the reactor where the
cracking reactions occur.
Cyclones (3) extract the
cracked hydrocarbon vapor
and pass it to the fractionating
column where it is
petroleum gases and gasoline
(4), light gas oil (5), medium
gas oil (6), and heavy gas oil
(7). Spent catalyst meanwhile
is mixed with steam (8) and
carried in a current of hot air
(9) to the catalyst regenerator
where it is cleaned and
recycled (10. Waste gases are
drawn off (11) and vented.
Other processing in Refining
A physical process
A solvent is used to
or to remove
Catalytic Reforming and
Catalytic Reforming Alkylation (isomerization)
A chemical process A chemical process
Changes straight chain Changes straight chain
alkanes in to benzene alkanes into branched
or aromatic alkanes
hydrocarbons. Branched alkanes can
The aromatics can also burn better than
burn better. straight chain alkanes.
Hydrocracking uses H2 to break longer chains into smaller
Removing Sulfur from
1. Gasoline is vaporized at 500 oC
2. Hydrogen Gas is injected and reacts with
sulfur to form hydrogen sulfide gas
3. The mixture is cooled and the H2S(g) is
4. The H2S(g) is converted to liquid sulfur for
use in fertilizers and asphalt.
Organic compounds can undergo:
• CxHy + O2 CO2 + H2O(g)
This is exothermic producing heat and light
• CxHy + O2 C or CO or CO2 + H2O(g)
This occurs when amounts of oxygen are
low, they can still be balanced as usual.
Alcohols can be produced 3 different ways.
Alcohols are compounds with an OH functional
group (Hydroxyl) on a carbon skeleton.
Alcohols with up to 4 carbon atoms are soluble in
water as a result of the OH group on the carbon
As more carbon atoms are added to the chain the
Alcohols have higher boiling points than do the
hydrocarbons from which they are formed from.
Types of Alcohols
There are three types of alcohols: Primary,
Secondary, and tertiary. These types of alcohols
are determined by “where” the OH is on the carbon
Primary : OH is at the end of a carbon chain.
Secondary: OH is in the middle, with 2 C atoms
attached to the C with the OH.
Tertiary : OH is in the middle with 3 C atoms
attached to the C with the OH.
Diagram a primary alcohol below : ( ethanol)
• Diagram a secondary alcohol below: (2 – butanol)
* Diagram a tertiary alcohol below: 2-methyl-2-propanol
Alcohols are named by finding their hydrocarbon skeleton
and ending this with “ol”.
The OH group is identified to which carbon in the chain it is
Name the following alcohol and identify it as primary,
secondary, or tertiary.
Alcohols can have more than one OH group on a
Alcohols with two OH’s are called diols, and the
prefix di is added before the “ol” in naming.
Alcohols with three OH’s are called triols, and the
prefix “tri” is added before the “ol” in naming.
Write the structural formula for 1,2-ethanediol. This is
also known as ethylene glycol or antifreeze.
Naming and Classifying
1) Draw the structural formula for the following
alcohols and classify them:
a) 3-hexanol b) methanol
c) 1,2,3-propanetriol (glycerol)
Alcohols can be produced three ways :
1) From using bacteria or yeast in the process of
fermentation. (ethanol and carbon dioxide are the
waste products of yeast as they eat sugar) 12%
2) Addition of water to an alkene. (with an acid
3) Hydrolysis of a halocarbons.
• Diagram the formation of ethanol from ethene +
water ( with an acid catalyst H2SO4)
* Diagram the formation of ethanol from the
hydrolysis (splitting by water) of chloroethane.
Helpful Websites for Alcohols
Halocarbons are organic compounds in which
halogens have replaced hydrogen.
Halocarbons are named as to where the halogens are
attached, and how many halogens there are.
The halogen prefix is used : fluoro, chloro, bromo,
Halocarbons are used
extensively as pesticides,
insecticides, dry cleaning,
and other areas.
Many of the most toxic
chemicals have been
PCB’s : poly chlorinated
biphenols, are toxic
DDT : a halocarbon which
chlorophenyl) ethane was banned in 1972
PCB’s are halocarbons
which contain two phenols
with chlorine on them.
PCB’s have been shown to
be accumulative in fatty
tissue, and bioaccumulate.
The biphenols typically can
persist in soil for 15-25
Draw the structure for the following :
a) Trichloromethane (chloroform)
b) Tetraiodomethane: c) 2-fluoro pentane
Ethers are organic compounds which have an oxygen atom
bonded to two different carbons.
Ethers are named by naming the compound on each side and
ending in “ether”. Or by writing the short version of each
with “oxy” in the middle.
Ethers were used anesthetics, but safer gases have been
Small ethers are soluble in water, but larger ethers are
Applications of ethers are solvents, gasoline additive, etc.
• Draw the structural diagram for the following :
a) Dimethyl ether b) methoxypentane
c) Diethyl ether d) Diphenyl ether
Aldehydes are organic compounds which have a
carbonyl group(C=O) at the end of a carbon chain.
Aldehydes are named by ending the molecule with
Diagram ethanal, and propanal below:
Uses of Aldehydes
Aldehydes are used as preservatives, flavorings,
Vanilla flavoring and cinnamon are natural aldehyde
Ethanol is converted to acetaldehyde (propanal) in
the human body.
Ketones are a class of organic compounds with a
carbonyl group (C=O) in the middle of a carbon
chain. (Ketones are never alone)
Propanone is the simplest ketone and is known as
acetone. Acetone is a top 50 industrial chemical.
Acetone is a common solvent for nonpolar
substances. (fingernail polish remover)
To name ketones end the carbon chain in “one”.
Organic Acids (Carboxylic
Carboxylic acids are a group of organic compounds
which have a (COOH) functional group.
Carboxylic or organic acids are weak acids.
Examples are : acetic acid, citric acid, benzoic acid,
To name these acids use the carbon chain root : and
add the suffix “oic” and the word acid.
Naming Organic Acids
Draw the structure for the following organic acids:
a) Methanoic acid b) Ethanoic acid
c) Butanoic acid d) Propanoic acid
Properties of Organic Acids
Methanoic acid (formic acid) is the acid in bee and ant
Ethanoic acid is acetic acid, found in vinegar
Small chain organic acids are soluble in water.
Lactic acid is an organic acid which builds up in body cells.
Ascorbic acid (Vitamin C) is found in citrus fruits and
Bacteria reacts butter into butanoic acid. (rancid butter)
Esters are organic compounds formed when an alcohol is
added to an organic acid.
Esters have distinctive odors.
Esters have the functional group : (COOC)
Esters are named by naming the alcohol name first ending in
“yl”, then the acid name is given ending in “oate”.
When an ester is synthesized from an alcohol and organic
acid, the alcohol gives off the (O) atom , and the acid gives
two (H) atoms to form water.
Diagram the reaction of ethanoic acid with
methanol. Name the ester which forms.
Draw the structural formula for the following
a) Ethyl butanoate b) pentyl ethanoate
An amine is an organic
contains an “amino”
An amino functional
group is NH2
Amines can contain
Amines are named by
adding the suffix “amine”
to the root name of the
Amines are also named by
naming the hydrocarbon
ending in “yl” with the
Amines are important
Amino acids which make
up proteins contain an
amino group along with an
organic acid group.
Amines are found in DNA.
Amines are the basis of
several addictive drugs :
nicotine, cocaine, and Methamphetamine
Draw the structure for the following amines.
a) Butanamine b) pentylamine
Amides are produced when
amines are added to an
Amides have an amino
group and a carbonyl group
attached to an end carbon.
Amides are by adding the
suffix “amide” to the end
of the hydrocarbon root.
Amides are found in
and in some synthetic
polymers such as
Nylon : a polymer with an amide
group in the chain.
Draw the structure of
What is the name of the amide above?
Organic Compound Summary
• The following are the organic compounds we’ve
studied. They are identified by their “functional
• Hydrocarbons * Esters
• Alcohols * Organic Acids
• Ethers * Amines
• Ketones * Amides
• Aldehydes * Halocarbons
Small organic molecules
(monomers) can be reacted
to form long organic
Example of polymers are :
nylon, polyester, etc.
Polymers can be formed by
a condensation reaction
(water is produced)
Polymers can be
formed by an
where a simple
molecule (water, etc.)
is removed and a new
compound is formed.
PVC : polyvinyl chloride
Other polymers include
Nylon is a polymer
involving an amide
Nylon was synthesiszed in
the 1930’s and named after
the cities of New York and
Nylon is produced by
adding an organic acid to
Nylon has many uses.