Alcohols, Halagenoalkanes and Analysis

Alcohols, halogenoalkanes
and analysis…read more

1) Making and using alcohol
· Hydration of ethene
· Ethene (C2H4) can go through catalytic hydration using
a) steam
b) presence of phosphoric acid catalyst (H3PO4)
c) High temperatures and moderate pressure
· Reaction is reversible therefore the reaction of ethene
is incomplete. Each time it is passed through reactor,
only 5% of ethene is converted into ethanol and un-
reacted gases are recycled and put into reactor again
until 95% conversion is achieved.…read more

Fermentation
· Carbohydrates (sugars and starches) are
converted into ethanol and carbon dioxide.
· Ethanol has a concentration of up to 14% by
volume
· Using:
· Low Temperatures
· Presence of yeast and enzyme in the yeast called zymase.
· At temperatures above 37, enzyme starts to denatures and
lose efficiency
· Must be carried out in the presence of air to prevent
undesirable products such as ethanal/ethanoic acid being
used which can change the flavour of the product
· Anaerobic process- does not require oxygen…read more

Uses of alcohols
· Ethanol in alcoholic drinks. Ethanol can also be used in
perfumes, aftershaves and cleaning products. It is
being developed as fuel in cars.
· The ethanol used in drinks is made using fermentation.
Products are combined with yeast to produce beers
and larger of varying tastes
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· Ethanol as a fuel: 10% of ethanol is blended with
petroleum to increase the RON. Fuel will burn more
easier. Fuels made with ethanol are environmentally
safe as they are made from renewable sources…read more

Ethanol in methylated spirits: methylated spirits
contain ethanol that is mixed with small amounts of
ethanol and coloured dye, making the ethanol mixture
toxic and undrinkable. Methylated spirits are cheaper
than ethanol in alcoholic drinks .it is used for removing
paint or ink stains
· Uses of methanol: can be sued as clean- burning fuel.
Often used as additive in race cars . It smells and tastes
like alcohol but is very toxic and even a small amount
could lead to organ damage or death . It can be easily
converted into methanal and ethanoic acid…read more

Properties of alcohols
Physical properties: alcohols produce hydrogen bonds
between O-H groups
Volatility and boiling point: hydrogen bonds are strongest
types of intermolecular bonds. Hydrogen bonds allow
relatively high boiling and melting points of alcohols.
VOLATILITY IS THE EASE THAT A LIQUID TURNS INTO A
GAS AND IT INCREASES AS BOILING POINT DECREASES.
Alcohols have a lower volatility than alkanes…read more