ORGANIC CHEMISTRY
 Organic chemistry is the study of ................containing
compounds derived from living organisms.
 Oil is formed over millions of years from the break down of
dead ................and ......................
80+ million
compounds- natural
& synthetic.

Crude Oil (petroleum) is a mixture of many thousands of these
different compounds and is the main source of many of these
chemicals.

They are called .................. because they predominantly
contain the elements hydrogen and carbon.
Distillation of Crude Oil
...................
Lower boiling point
substances ...............
and move up.
As the temp drops
substances ..............
and run off.
..................temp
temp
Homologous series
This is a series of compounds which all contain the same
........................ group, and have similar chemical
properties.
ALKANES
ALKENES
ALCOHOLS
CH4
CH2 =CH2
CH3OH
CH3-CH3
CH2 =CH –CH3
CH3CH2OH
Each has a ...........................formula:
......................: CnH2n+2
The members of the series differ by the number of ......
units.
CH3-CH3, CH3-CH2-CH3, CH3-CH2-CH2-CH3
Graduation in physical properties: eg: boiling points.
CH4 (......), C8H18 (..........), C30H62 (..............)
ALKANES
SATURATED HYDROCARBONS – contain maximum amount of
……………………………. - only ……………………….. bonds (no ………………………..
bonds)
NAMING ALKANES
No of C atoms
Prefix
Formula
Alkane
1
Meth
CH4
Methane
2
Eth
CH3CH3
Ethane
3
Prop
CH3CH2CH3
Propane
4
But
CH3CH2CH2CH3
Butane
5
Pent
CH3CH2CH2CH2CH3
Pentane
6
Hex
C6H14
Hexane
7
Hept
C7H16
Heptane
8
Oct
C8H18
octane
Functional
groups
The
functional
groups are
………………. or
…………………..
of atoms
which
determine
the
…………………….
of organic
molecules.
STRUCTURES OF ALKANES
METHANE ……….
Bond Angle
…………….
Can be illustrated as:
Shape
………………………
ETHANE.
Molecular formula …………...
Structural formula:……………………….. OR
…………………
…………….
ETHANE.
Molecular formula C2H6
Structural formula: CH3 CH3
or
H
Atoms are able to spin around a single
bond there is free rotation.
H
H
C
C
H
H
H
PROPANE.
....................formula: C3H8
.....................formula: CH3 CH2 CH3 or
Both ethane and propane are
“……………………” chain molecules
BUT!!
H
H
H
H C
C
C
H
H
H
H
Bonds are ……… 90o molecules are NOT…………….!!!
Schematic formula
PROPANE.
Molecular formula: C3H8
Structural formula: CH3 CH2 CH3 or
Both ethane and propane are
“straight” chain molecules
BUT!!
H
H
H
H C
C
C
H
H
H
H
Bonds are NOT 90o molecules are NOT STRAIGHT!!!
Straight = no branches!
Schematic formula
Ethane and propane are also colourless and
odourless flammable gasses. They have
slightly higher boiling points due to their
greater molecular weights.
ISOMERS
C4H10 - can have two different structures
Straight chain. CH3 CH2 CH2 CH3
Branched chain CH3 CH
CH3
CH3
BUTANE
METHYL PROPANE
branch
Compounds that have the same molecular formula but different
structural formula are said to be ISOMERS of each other.
TASK: illustrate the structures of the three different isomers of
C5H12.
Use models OR CHEMSKETCH to help you.
Names & Structures
Examples
2- methylbutane
The 2 can be left off as there are ………………………………………………
2 and 3-methylbutane are the same molecule!
2,2 – dimethyl propane
TASK: illustrate the structures of:
2-methylpentane.
2,3 – dimethylbutane.
2,2,3 -trimethylpentane
THE RULES FOR NAMING ORGANIC COMPOUNDS
1.
Choose the longest unbroken chain of Carbon atoms and assign a name
for the carbon chain using the prefixes; meth-1,
eth-2 etc.
2.
Identify any carbon chain branches (alkyl groups). These are assigned
names using the same prefixes as above along with the suffix “-yl” –
methyl, ethyl etc.
3.
Identify the functional groups present in the molecule. Assign a prefix
or suffix according to their homologous series. These will be written in
front of the name of the carbon chain.
5. Number the Carbon atoms in the longest chain so that the
branches/functional groups have the lowest number possible. Allocate a
number for every group/branch no matter how many times it occurs.
Where groups are on the same carbon write their names in alphabetical
order.
6.
Prefixes are used for groups that occur more than once.
Di – 2
Tri – 3
Tetra – 4
Penta – 5 etc.
7. Groups are written in alphabetical order.
8.
The final name is written as one word with commas between numbers,
hyphens separating numbers from words.
Give the names of the following alkanes
(a) CH3 CH2
CH
CH2 CH3
CH3
(b) CH3 CH
CH3
CH2
CH
CH3
CH3
(c) CH3 C(CH3)2 CH2 CH(CH3) CH2 CH3
(d) CH3CH2CH(CH3)C(CH3)3
Structure of Alkenes
The shape around the double bond is …...................
The bond angle around the double bond is .................
………………..
Represented as

C bond

C
C
C
………..
Examples of Alkenes
………………, C2H4
H
H
C
H
PROPENE
OR …………………….
C
H
CH2
CH
CH3
TASK: Use ball & stick models or sketches to construct and name 3
different structures for C4H8 each one with one double bond.
Alkynes
H-C≡C-H
H-C≡C-CH3
H-C≡C-CH2-CH3
CH3-C≡C-CH3
…….yne
……..yne
Very reactive
Triple bond unstable!
Attracts electrophiles.

C
x
x
x
Cx
…………-1-yne
Alkynes are very unstable
………….yne and reactive. Acetylene
burns with very high
temp?