Functional Groups
IB
Objectives
• Concepts:
• –Functional group, alkane, alkene, alkyne, alcohol,
carbonyl, aldehyde, ketone, carboxylic acid, ether,
ester, amine, amide, halogenoalkane
• –Primary alcohol, secondary alcohol, tertiary alcohol,
primary amine, secondary amine, tertiary amine,
• Skills:
• –Draw and state names of the compounds containing
up to six carbon atoms with the following functional
groups: aldehyde, ketone, carboxylic acid, alcohol,
amide, amine, ester and halogenoalkane.
Functional Groups
• As has already been indicated, alkanes are
relatively unreactive.
• For an organic molecule to be reactive it needs
something additional.
• A site of reactivity in an organic molecule is called
a functional group.
• C=C double is a functional group.
• Other functional groups contain elements other
than C or H, notably O, N and Cl.
Functional Group
• A functional group could be an atom or a
group of atoms within a molecule that is
responsible for its characteristic
chemical reactions.
alkanes
H H
• Only carbon and
hydrogen
H C C H
• All single bonds
• Their names end
with -ane H H
Ethane
alkenes
• Only carbon and H H
hydrogen
• A carbon to carbon C C
double bond
H H
• Their names end
with -ene
Ethene
alkynes
• Only carbon and
hydrogen
H C C H
• A carbon to carbon
triple bond
• Their names end
with -yne
Ethyne
alcohols
• Only one oxygen H H
• Has an O-H group
• Can be classified as H C C O H
1º/2º/3º according to
position of O-H H H
group on carbon
skeleton Ethanol
• They are named as
alkanol
H H
H H
H O H H O H
H C C O H H C C C H H C C C H
H H H H H
H H
C H3
• Primary alcohol • Secondary alcohol • Tertiary alcohol
aldehydes
• Only one oxygen
H
O
• Has a C=O group
• C=O group is at the H C C
end of the carbon
chain, so is next door
H
to a hydrogen atom
H
• They are named as Ethanal
alkanal
ketones
• Only one oxygen H O H
• Has a C=O group
• C=O group is not at
the end of carbon H C C C H
chain, so is next
door to 2 carbons H H
• They are named as
alkanone Propanone
esters
• Has 2 oxygens H
O
• One oxygen is H
part of a C=O H C C
bond, the other is O C H
next door, H
sandwiched H
between two
carbons. Methylethanoate
• They are named
as Alkylalkanoate
carboxylic acids
• Has 2 oxygens
H
• Has O-H and C=O O
groups on the same
carbon atom H C C
• This -COOH group
has to be at the end O H
of a carbon chain.
H
• They are named as Ethanoic acid
alkanoic acid
ether
• Has 1 oxygen H H H
• No O-H or C=O
group H C C O C H
• The oxygen is
sandwiched H H H
between two
carbon atoms
• Their names end Ethylmethylether
with -ether
Amines
• Contain Nitrogen H H
• Has an –NH2 group
• Can be classified as H C C N H
1º/2º/3º according to
the number of H H H
carbon atoms
connected to the N Ethylamine
• They are named as
alkyl amine
Amide
• Has NH2 and C=O H
groups on the same O
carbon atom
• They are named as
H C C
alkanamide N H
H
H
Ethanamide
Haloalkanes
H H
• Have the general
formula R-X where
H C C Cl
R is an alkyl group
and X is a halogen
• They are named as H H
haloalkanes
Chloroethane
What family does it belong to?
H H
C C
H H
What family does it belong to?
H
O
H C C
H
H
What family does it belong to?
H
H O H
H C C C H
H H H
What family does it belong to?
H H
H C O C H
H H
What family does it belong to?
H
O
H
H C C
O C H
H
H
What family does it belong to?
H O H
H C C C H
H H
What family does it belong to?
H H
O
H C C C
O H
H H
What family does it belong to?
H
H C H
H
H C C O H
H H H
C
H