3. 14.4.2*
Ethanol is formed by the catalytic addition
of steam to ethene
http://www.chemguide.co.uk/physical/equilibria/et
hanol.html
4. 14.4.3
Combustion of ethanol
http://www.chemguide.co.uk/organicprops/alkanes/oxygen.h
tml
2C2H6 + 7O2 = 4CO2 + 6H2O
Complete Combustion of Ethane.
ethane+ oxygen carbon dioxide +water + energy
2C2H6(g) + 7O2(g) 4CO2(g) + 6H2O(l)
The reaction is exothermic (it gives out heat)
The products are the same (carbon dioxide and water)
More oxygen is required for the complete combustion
of ethane (compared to methane)
giving four times the quantity of carbon dioxide
and three times the quantity of water.
5. Trends
The hydrocarbons become harder to ignite as the molecules
get bigger. This is because the bigger molecules don't
vaporize so easily - the reaction is much better if the oxygen
and the hydrocarbon are well mixed as gases. If the liquid
isn't very volatile, only those molecules on the surface can
react with the oxygen.
Bigger molecules have greater Van der Waals attractions
which makes it more difficult for them to break away from
their neighbours and turn to a gas.
Provided the combustion is complete, all the hydrocarbons
will burn with a blue flame. However, combustion tends to be
less complete as the number of carbon atoms in the
molecules rises. That means that the bigger the
hydrocarbon, the more likely you are to get a yellow, smoky
flame.
8. Uses of ethanol
Drinks
The "alcohol" in alcoholic drinks is simply ethanol.
Industrial methylated spirits (meths)
Ethanol is usually sold as industrial methylated spirits which is ethanol
with a small quantity of methanol added and possibly some colour.
Methanol is poisonous, and so the industrial methylated spirits is unfit
to drink. This avoids the high taxes which are levied on alcoholic drinks
(certainly in the UK!).
As a fuel
Ethanol burns to give carbon dioxide and water and can be used as a
fuel in its own right, or in mixtures with petrol (gasoline). "Gasohol" is a
petrol / ethanol mixture containing about 10 - 20% ethanol.
Because ethanol can be produced by fermentation, this is a useful way
for countries without an oil industry to reduce imports of petrol.
As a solvent
Ethanol is widely used as a solvent. It is relatively safe, and can be used
to dissolve many organic compounds which are insoluble in water. It is
used, for example, in many perfumes and cosmetics.
9. MAKING ALKENES IN THE LAB
http://www.chemguide.co.uk/organicprops/alkenes/maki
ng.html#top
