Benzene
Barbora Bakajová
Tereza Šimšová
What is benzene?
Benzene
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an organic chemical compound
a colorless and flammable liquid with a
pleasant, sweet smell
a known carcinogen
a component of gasoline
production of drugs ,plastics, synthetic rubber,
and dyes
flammable - hořlavý
History
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was discovered in 1825 by the English
scientist Michael Faraday
he isolated it from oil gas and gave it the name
bicarburet of hydrogen.
In1833, the German chemist Eilhard
Mitscherlich produced it by the distillation of
benzoic acid and lime.
Symbols
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Two version:
1) the delocalised electrons are represented by
a circle within the hexagon
2) the Kekulé form where alternate single and
double bonds are shown.
Structure
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structure is called a resonance hybrid.
mesomeric structure
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This delocalisation of electrons is known as
aromaticity, and gives benzene great stability
Properties
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molar mass:78,11 g/mol
density:0,8786 g/cm3
phase: liquid
melting point:5,5 °C (278.6 K)
boiling point:80.1 °C (353.2 K)
viscosity:0.652 cP at 20°C
molecular shape :planar
Uses
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an industrial solvent and degreasing metal
increases the octane rating
derivatives of benzene :
- styrene :polymers and plastics
- phenol :resins and adhesives
- cyclohexane :nylon manufacture
degreasing-odmašťování
resins-pryskyřice
Reactions of benzene
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1)S halogenations of alkyl benzene side-chain
2)A addition on C=C of alkyl benzenes
3)A reduction of aromatic hydrocarbons
4)S Ar Friedel Crafts alkylation ,acylation
5)Oxidation of alkyl benzene side-chain
R
E
R
E
Reaction of benzene
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Friedel-Crafts alkylation SEAr
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the Friedel-Crafts alkylation involves the
alkylation of an aromatic ring (such as
benzene) and an alkyl halide using a strong
Lewis acid catalyst.
Health effects
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breathing :very high levels →death,also headache,
tremors, confusion,….
eating or drinking foods containing high levels:
irritation of the stomach, convulsions, rapid heart
rate, and death convulsions
chronic effect :damages bone marrows ,leads to
anemmia
tremor-třes
convulsion-křeč
bone marrow-kostní dřeň
Sources
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wikipedia.org/wiki/Benzene
Organic chemistry-lectures(VUT)
Thank you for your attention