Transcript Hess’s Law

What do aspirin, Tylenol, ibuprofen, almonds,
vanilla, and mothballs have in common?
O
OH
O
OH
O
O
O
H
H
OH
O
HN
O
O
OH
CH3
aspirin
Tylenol
ibuprofen
Aromatic ring
almonds
vanilla
Structural Properties:
Planar
All C atoms sp2 hybridized
All C-C bonds equal length
 electrons
“smeared out”
Resonance structures
mothballs
Structure of Benzene
H
H
C
C
C H
H C
C
H
Kelter, Carr, Scott, Chemistry A World of Choices 1999, page 212
C
H
Benzene
3-D
– VSEPR Diagram
Kelter, Carr, Scott, Chemistry A World of Choices 1999, page 212
Aromatic Compounds
Benzene, C6H6
Chemical Properties
Special Stability (aromaticity)
No addition reactions
CH3
OH
Toluene
NH2
Hf
Aniline
-156 kJ/mol
+ 118 kJ/mol
-38 kJ/mol
+ 113 kJ/mol
Aromatic substituents:
phenyl
75 kJ/mol
- 26 kJ/mol
49 kJ/mol
Phenol
benzyl
Benzene
• C6H6
• Uses: styrene; phenol;
synthetic detergents;
cyclohexane for nylon;
DDT; insecticides;
fumigants; solvent; paint
removers; rubber cement;
antiknock gasoline
Cl
Names of
monosubstituted
benzene rings
Br
Bromobenzene
OH
Phenol
Chlorobenzene
NO2
Nitrobenzene
CH3
Toluene
CH=CH2
Styrene
OH
Phenol, (carbolic acid)
• C6H5OH
• Uses: solvent for refining
lubricating oils; salicylic
acid; phenoltpthalein;
germicidal paints;
pharmaceuticals;
laboratory reagent;
slimicide
Benzene
Mark Wirtz, Edward Ehrat, David L. Cedeno*
NO3-
Nitrobenzene
Aromatic
Hydrocarbons
Kelter, Carr, Scott, Chemistry A World of Choices 1999, page 430
Cholesterol
Compounds
CH3
6
C
C
1
C ortho
C
2
5
C
para
4
C
3
meta
position number
1, 2
1,3
1,4
name
ortho- (o-)
meta- (m-)
para- (p-)
CH3
H
6
C
C
1
C CH3
H C
2
5
C
H
4
C
3
H
ortho-dimethylbenzene
or
1, 2 - dimethylbenzene
CH3
H
6
C
C
1
C H
H C
2
5
C
H
4
C
3
CH3
meta-dimethylbenzene
or
1, 3 - dimethylbenzene
CH3
H
6
C
C
1
C H
H C
2
5
C
4
CH3
C
3
H
para-dimethylbenzene
or
1, 4 - dimethylbenzene
MD
H
6
C
C
1
C H
H C
2
5
C
4
MD
C
3
H
para-docs
or
paradox
MD
H
6
C
C
1
C MD
H C
2
5
C
H
4
C
3
H
ortho-docs
or
orthodox
Fe2+
Fe2+
6
C
C
1
C Fe2+
Fe2+ C
2
5
C
4
Fe2+
C
3
Fe2+
ferrous wheel
or
ferris wheel
NO2
H
C
C
C NO2
H C
C
H
C
H
o - dinitrobenzene
or
1, 2 - dinitrobenzene
NO2
CH3
C
CH3
C
C H
O2N C
Toluene
C
H
C
NO2
2,4,6 - trinitrotoluene
or
TNT
CH3
2,4,6 -Trinitrotoluene
NO2
O2N
NO2
• CH3C6H2(NO2) 3
• Uses: Explosives;
intermediate in dyestuffs
and photographic
chemicals
• Will detonate only if
vigorously shocked or
heated to 450oF
CH3
Cl
C
CH3
C
C Cl
H C
Toluene
C
Cl
C
H
2, 4, 6 - trichlorotoluene
or
2, 4, 6 -trichloromethylbenzene
O
O C CH3
H
C
C
C COOH
H C
C
H
C
H
2-acetyloxybenzoic acid
or
(acetylsalicylic acid or aspirin)
H
H
C
C
C
H
C
H
C C
Cl C
H
H
C
CClCl
Cl C
3
C
C
Cl
H
H
dichlorodiphenyltrichloroethane
or
DDT
C
C
C
H
Cl
CH CH2
H
C
C
C H
H C
C
H
C
H
n
phenyl ethene
or
polystyrene a.k.a. (styrofoam)