Phenol
Definition
Aeromatic alcohols are called Phenols.
OR
Those derivations of benzene in which hydrogen atom is replaced by OH
group are known as Phenol.
Classification of Phenol
On the basis of hydroxyl group (OH)
bonded with benzene ring, Phenol are classified into following three classes.
1. Mono Hydric Phenol
2. Di Hydric Phenol
3. Tri Hydric Phenol
1. Mono Hydric Phenol
Those aeromatic phenols which
contains only one OH group are called Mono Hydric Phenol.
2. Di Hydric Phenol
Those aeromatic phenols which contain
two OH groups are called Di Hydric Phenol.
Diagram Coming Soon
3. Tri Hydric Phenol
Those aeromatic phenols which contain
three OH groups are called Tri Hydric Alcohols.
Preparation
Phenol can be prepared by following
methods.
1. From Chloro Benzene (Down’s Process)
When chloro benzene is heated with
10% NaOH solution at 300ºC under 200 atm pressure then sodium Phenoxide is
formed, which on further heating with HCl convert into Phenol.
Diagram Coming Soon
2. From Benzene Sulphonate
When benzene sulphonate is fused with
NaOH at 25ºC ten sodium Phenoxide is formed, which on further heating with HCl
convert into Phenol.
Diagram Coming Soon
Physical Properties
1. At ordinary temperature and pressure,
phenol exist as colourless, crystalline solid.
2. Phenol has peculiar smell.
3. Phenol is a poisonous compound.
4. The melting point of phenol is
43ºC and its boiling point is 182ºC.
5. Above 68.5ºC Phenol is completely
soluble in water.
Chemical Properties
The important chemical reactions of
Phenol are
1. Reaction with Sodium Hydroxide (NaOH)
When phenol reacts with NaOH then
sodium Phenoxide and water are formed. This reactions shows the acidic nature
of phenol.
Diagram Coming Soon
2. Reaction with Zinc Dust
When vapours of phenol are passed
through red hot zinc dust then benzene is formed.
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3. Hydrogenation
Introduction of hydrogen in a
compound is called Hydrogenation. In presence of catalyst nickle when phenol is
heated with hydrogen at about 150ºC then hydrogenation takes place as a result
cyclo hexanol is formed.
Diagram Coming Soon
4. Reaction with Bromine Water
In presence of water, when bromine
reacts with phenol then 2, 4, 6 – tri bromo phenol is formed.
Diagram Coming Soon
5. Reaction with Concentrated Nitic Acid
When phenol reacts with concentrated
nitric acid then 2, 4, 6 – tri phenol (Picric Acid) is formed.
Diagram Coming Soon
6. Reaction with Dilute Nitric Acid
When Phenol react with dilute nitric
acid then a mixture of ortho and Para nitro Phenol is formed.
Diagram Coming Soon
7. Reaction with Sulphuric Acid
When phenol reacts with H2SO4 then
ortho phenol sulphonic acid and para phenol sulphonic acid are formed. The
amount of product depending upon the temperature, lower pressure i.e. (15 –
20ºC) favours the production of ortho phenol sulphonic acid where as high
temperature about 100ºC favours the production of para phenol sulphonic acid.
Diagram Coming Soon
Uses
1. Phenol is uses as antiseptic.
2. Phenol is used in the manufacture
of soaps, plastics etc.
3. Phenol is used in the preparation
of Picric Acid and Aspirin.
4. It is used as link Preservative.
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