1. Alcohols and Carbonyls
Ethanol. Alkanol family, Aldehydes and Ketones. Methanol and Methanal

2. Index Ethanol Homologous series CnH2n+1OH Alcohol structures
Oxidation of alcohols
Aldehydes and Ketones
Methanol

3. Ethanol C2H5OH Functional group -OH + -
Hydrogen bonding allows ethanol to dissolve
in water, pH 7. b.p. 78 oC.
This effect decreases in alcohols
as the length of the hydrocarbon chain increases. H C C H H OH
Hydroxyl group
Ethanol is a good solvent, it behaves both like water and other hydrocarbon solvents. H O R - +
Combustion of ethanol
CH3CH2OH O2  2 CO H2O H = kJ mol -1
Ethanol can be used as a fuel in cars.

4. Ethanol C2H5OH Manufacture of Ethanol 1. Fermentation yeast
Fermentation is used to make all alcohol based drinks.
Any vegetable matter containing carbohydrates can be used.
yeast
C6H12O6  2CH3CH2OH CO 2
2. Hydration of Ethene (Industrial manufacture of Ethanol)
C2H H2O  CH3CH2OH
Cracking fractions from crude oil is a cheaper way to produce ethanol.
(more expensive than making petrol)
Reaction Conditions:
300oC , High Pressure 60 Atm. , phosphoric acid catalyst.

5. Uses of Ethanol
Drinks
Ethanol is a natural product of fermentation. Ethanol cannot be more than 15% of the fermentation mixture, as ethanol is a poison and will kill the yeast.
Solvent
In varnishes (as it evaporates easily), dyes, perfumes and
drugs.
Chemical
feedstock
In the production of vinegar, ether, chloroform and
ethyl esters and ethene.
Increasingly seen as an important fuel. Meths is ethanol
with added methanol. Cars can use ethanol as a fuel.
Fuel
Others
In thermometers (cheaper and safer than Hg and
de-icers.

6. Dehydration of ethanol
Catalyst
CH3CH2OH  C2H H2O
Ethanol
Ethene
When hot ethanol is passed over aluminium oxide
ethene gas is produced.
Ethene is very a very important chemical, it is the basis
for many plastics. E.g. Polythene

7. Homologous Series CnH2n+1OH
Functional molecular structure
Methanol, CH3OH; Ethanol C2H5OH; Propanol C3H7OH
Straight chain isomers of Alkanols
Propanol C3H7OH, has 2 isomers, propan-1-ol and propan-2-ol. C H OH C H OH
propan-1-ol
propan-2-ol

8. alcohol (alkanol) 4 C’s  butanol 2-methylbutan-1-ol H C OH CH3
Naming alcohols
1. Decide on the type of compound (ie. consider functional group)
alcohol (alkanol)
2. Select the longest chain
4 C’s  butanol
3. Name the compound with the branched chains in ascending order.
2-methylbutan-1-ol

9. Different types of alcohol
Primary alcohol,
1 C joined to the
C bonded to
the OH group
Secondary alcohol,
2 C’s joined to the
C bonded to
the OH group
Tertiary alcohol,
3 C’s joined to the
C bonded to
the OH group
CH3 C OH H
propan-2-ol
2-methylpropan-2-ol

10. Other Alcohols 1. Cycloalkanol 2. Diols (dihydric)
Cyclohexanol is a secondary alcohol
2. Diols (dihydric) C OH H
Ethane-1,2-diol
Anti freeze
3. Triols (Trihydric)
e.g. propane –1,2,3,triol or Glycerol is used in cosmetics, paints and
nitroglycerine explosives.

11. Oxidation of Alcohols aldehyde 1st 2nd aldehyde acid ketone
C=O carbonyl group
Primary alcohols can be oxidised in two stages,
1st Stage - Hydrogen is lost; 2nd Stage - oxygen is gained. C
O H H + O R
oxidation
H2O
aldehyde
1st
2nd O + C H R
aldehyde
acid
oxidation R C R1 O
ketone
Secondary alcohols can be oxidised to form ketones,
Tertiary alcohols do not undergo oxidation.

12. Aldehydes and Ketones CHO alkanal functional group
C=O ketone functional group
Aldehydes and Ketones
CH3
C = O
Propanone, nail varnish remover and
is used in the making of perspex H
C = O - +
Methanal, 40% in water is formalin,
and is used to make polymers
CH3 H
C = O
Ethanal, It’s trimer (CH3CHO)3 is used as a
sleep inducing drug. It also causes a hangover
CH3CH2
CH3
C = O
Butanone, is a solvent used to make VHS tapes.
Butan-2-one
C4H8O

13. Aldehydes and Ketones RSC video on silver mirror Distinguishing tests
(Using mild oxidising agents.)
Aldehydes are oxidised to carboxylic acids
1. Fehlings solution contains Cu2+ ions (blue) which form Cu+ ion
(orange-red) in the presence of aldehydes.
2. Tollen’s reagent contains Ag+ ions, which form Ag in the presence
of aldehydes (silver mirror test)
3. Acidified Potassium Dichromate orange Cr2O72-(aq) to green Cr3(aq)
Ketones do not react with oxidising agents.

14. Methanol, Steam reforming
The steam used must be pure.
Carbon steam  Carbon monoxide hydrogen
1. Coal
1000 oC
synthesis gas
Methane steam  Carbon monoxide hydrogen
2. Natural Gas (UK)
900 oC
Ni Catalyst
30 Atmos
synthesis gas
Methanol is oxidised into methanal, either by:
1. Zinc/Chromium oxide catalysts oC and Atm.
2. Cu/Zn/Al oxide catalysts oC and Atm.
CH3OH O2  HCHO + H20

15. Uses for Methanol and Methanal
Fuel
Added to ethanol to make meths, cleaner flame than hydrocarbons.
Added to petrol octane number 114. MTBE (Methyl Tertiary Butyl Ester)
Can be converted into petrol using Zeolite.
Drugs and Fabrics
Formalin,
preserve biological specimens
Polymers
Polymethanal, machine parts
Melamine, Electrical insulators
Phenol methanal, heat resistant are all thermosettings plastics