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Unit 7: Organic Chemistry - Coggle Diagram
Unit 7: Organic Chemistry
Fractional Distillation
Crude oil
is the
raw ingredient
and it is also the
non-renewable fuel
source for
fractional distillation
Fractional column
has a
temperature gradient
(
the higher you go, the cooler it is
)
Alkanes
C-C
bonds
CnH2n+2
Saturated
compounds
complete combustion
End in "
ane
"
Alkenes
Cn2n
Incomplete
combustion
C=C
bonds
More reactive than alkanes
because of C=C bonds
Reactions of Alkenes
Addition reactions
Alkenes all have the
functional group C=C
. This
bond will open up
when a
new atom is added to each carbon
It
adds two more
atoms as alkene is only CnH2n where as alkane CnH2n+
2
Hydrogenation
Hydrogen
can react with the alkene to
open up the double bond
Alkene reacted with hydrogen in presence of nickel
Alkene + hydrogen --> Alkane
Steam
Reactions
Steam
reacts with
alkenes
to
produce alcohols
E.g
Ethene mixed with steam over concentrated phosphoric acid makes ethanol
C2H4 + H2O --> C2H5OH
Ethene + water(g) --> ethanol
Used to make
ethanol industrially
Alcohols can be seperated
into alkene and steam back by fractional distillation
Halogen
Reactions
Alkenes can react with halogens
such as
bromine, chlorine and iodine
The
diatomic molecules
add onto the alkene
to
open up the double bond
into an
alkane
Test for alkene
Alkene
added to
orange bromine water
Shake
the
solution
If alkene is present
, it will make a
colourless compound
If not present
,
bromine water will stay
orange
Orange --> colourless
ends in "
-ene
"
Alcohols
Ends in "
ol
"
Cn H2n+1 OH
Flammable
Soluble
in water
Oxidised in air
to become
carboxylic acids
Used for solvents as they can dissolve into water
Used as
fuels
as they
burn cleanly
Such as
ethanol in spirit burners
Fermentation
Ethanol
is a
common ingredient
in
Alcoholic drinks
37 degrees optimum
slightly acidic
solution
anearobic
conditions
-
OH
Hydrocarbons
Only contains
Hydrogen and Carbon atoms
Properties change
as they
get longer
Shorter
chains
More
volatile
Less viscous
Longer
chains
Less volatile
Higher boiling
point
Can be
cracked into smaller hydrocarbons
as they are in
higher demand
Catalytic
cracking
Vaporise
(
thermal decompostion
)
hydrocarbons
. Then
pass vapour over hot powdered aluminium oxide catalyst
. The
long chain molecules then split apart
on the surface of the powdered catalyst
Creates short-chain hydrocarbons
such as a
shorter alkane molecule and an alkene
Steam
cracking
Vaporise
(
thermal decomposition
)
hydrocarbons then mix with steam
and
heat at high temperature
Combustion
Complete
combustion
Hydrocarbon + Oxygen --> Carbon dioxide + Water
Happens when there is
plenty of oxygen
Incomplete
combustion
Alkene + Oxygen --> Carbon + Carbon monoxide + Water
yellow smoky flame
less energy
released
Carboxlyic acids
-
COOH
-
anoic acid
React like acids
(see acids and alkalis)
Cn-1H2n+1
COOH
Methanoic acid exception
Weak
acids
Esters
-COO-
Formed from
alcohol and carboxylic acid
alcohol + carboxylic acid
-->
ester
+
water
Pro
panol +
ethan
oic acid -->
Pro
pyl
ethan
oate + water
Acid catalyst is used e.g
concentrated sulphuric acid
Naming Esters
The
alkyl group
is determined by the
alcohol
The
2nd part
is determined by the
carboxylic acid
Made by
oxidising alcohols
Polymers
Addition Polymers
Monomers
that
make up **
addition polymers
are
alkenes**
Alkenes
can
open up their double bond
and join together to form polymer chains.
Addition polymerisation
Long chain molecules
formed when
small molecules (monomers) join together
Naturally Occurring
Polymers
Proteins
are
polymers of amino acids
Starch, Cellulose
Condensation Polymerisation
Small molecules
such as
water
are
released
The
two reactive groups
are on the
end of each monomer
e.g (
OH
or
COOH
)
Biochemistry
Amino Acids
Functional groups
-NH2 and -COOH
Glycine
=
NH2CH2COOH
Polypeptides
Amino acids
can join to each other in
condensation polymerisation
reactions to
form polypeptides
General equation =
NH2CH2COOH --> (-NHCH2CO-)n + nH2O
Polyamides
Uses
dicarboxylic
(-COOH) monomers and
diamine
(-NH2)
monomers
Makes
water molecules
aswell as the
polyamide
General equation =
nCOOH-[]-COOH + nNH2-[]-NH2 --> (-CO-[]-CO-NH-[]-NH-)n +2nH2O