Benzene
Aliphatic Containing carbon atoms joined in straight or branched
chains
saturated unsaturated
Alicyclic Containing carbon atomsjoinedtogether in a ring which
is not aromatic
Arenes Organic compounds containing at least Ix benzenering
Aromatic in their structure
copy
8fttunsaturation
Benzene
hexagonalring popular Empirical CH
Faraday 1825
fractionally distelcrudeoil obtain
Burning burns w smokeyflame
oft C H Ratio 1 Il
A Cx oxidised soot
N B y Alkanes enHanta n an 2 AratiosMC H
Alkenes n an
Properties colourless sweetsmelling
Aflammable liquid
Carcinogen
Finding Molecular Burning calculateenergyreleaseperunit mass
Formula
QIMCAT
a
, Kekulé Stucture
Structure
1865 préhatingligingtéand double bonds
C C 3X C C 3
l dé density P reactive
Geometry 120 Trigonal planar
Reactivity
Issues x explain all physical chemicalproperties Regularshape
B stability
1 LackofReactivity Expectation C C Preactivity te density
Chemical Triene readilyundergo Addition ans
Instantaneous Br decolourisation
Benzene x readilyundergo electrophicAdditionRens
o Evidence x decolouriseBr
x behave likealkene tiene additionans
Conclusion Benzene l'stable hreactive
thanalkene
2 C C BondLength Expectation Triene Alternating c C and cc
Physical C C Shorter stronger CC longertweake
Ivregtskewed shape
a
µ y
o Benzene All C C bonds same length
Reg Hexagonalshape x alternatinglengths
Evidence X raydiffraction
C Cbenzene inbetweententhsof CCandEC
0 139mm
g
o
Equalbondangles 120
Conclusion Trienemodel x explainbondinggeometry
, EnthalpyofHydrogenation Expectation Trienereact w 3xHa cyclohexane
Chemical 1 AHhydrogenation 120KJmot
3x Atthydrog 360 KJmot
of Cyclohexane
2 zx EC
o Benzene Atthydrog 208KJmol
X 3X AHhydrogof cyclohexane
Lessexothermic
Conclusion oh energyrelease tiene l'stable
Delocalisede Pstability
Aliphatic Containing carbon atoms joined in straight or branched
chains
saturated unsaturated
Alicyclic Containing carbon atomsjoinedtogether in a ring which
is not aromatic
Arenes Organic compounds containing at least Ix benzenering
Aromatic in their structure
copy
8fttunsaturation
Benzene
hexagonalring popular Empirical CH
Faraday 1825
fractionally distelcrudeoil obtain
Burning burns w smokeyflame
oft C H Ratio 1 Il
A Cx oxidised soot
N B y Alkanes enHanta n an 2 AratiosMC H
Alkenes n an
Properties colourless sweetsmelling
Aflammable liquid
Carcinogen
Finding Molecular Burning calculateenergyreleaseperunit mass
Formula
QIMCAT
a
, Kekulé Stucture
Structure
1865 préhatingligingtéand double bonds
C C 3X C C 3
l dé density P reactive
Geometry 120 Trigonal planar
Reactivity
Issues x explain all physical chemicalproperties Regularshape
B stability
1 LackofReactivity Expectation C C Preactivity te density
Chemical Triene readilyundergo Addition ans
Instantaneous Br decolourisation
Benzene x readilyundergo electrophicAdditionRens
o Evidence x decolouriseBr
x behave likealkene tiene additionans
Conclusion Benzene l'stable hreactive
thanalkene
2 C C BondLength Expectation Triene Alternating c C and cc
Physical C C Shorter stronger CC longertweake
Ivregtskewed shape
a
µ y
o Benzene All C C bonds same length
Reg Hexagonalshape x alternatinglengths
Evidence X raydiffraction
C Cbenzene inbetweententhsof CCandEC
0 139mm
g
o
Equalbondangles 120
Conclusion Trienemodel x explainbondinggeometry
, EnthalpyofHydrogenation Expectation Trienereact w 3xHa cyclohexane
Chemical 1 AHhydrogenation 120KJmot
3x Atthydrog 360 KJmot
of Cyclohexane
2 zx EC
o Benzene Atthydrog 208KJmol
X 3X AHhydrogof cyclohexane
Lessexothermic
Conclusion oh energyrelease tiene l'stable
Delocalisede Pstability
