benzene and substitution reactions_2011 (2).ppt
TRANSCRIPT
New Way Chemistry for Hong Kong A-Level Book 3A1New Way Chemistry for Hong Kong A-Level
3A1
Benzene Benzene and and
Electrophilic Electrophilic Aromatic Aromatic
SubstitutionSubstitution
New Way Chemistry for Hong Kong A-Level Book 3A2New Way Chemistry for Hong Kong A-Level 3A2
Aromatic Hydrocarbons (Arenes)Aromatic Hydrocarbons (Arenes)• Simplest member : Benzene, C6H6
• Characteristic aroma• Alkylbenzene, Cn+6H2n+6
E.g. CH3
C6H5CH3 C6H5C2H5
New Way Chemistry for Hong Kong A-Level Book 3A33
Aromatic Hydrocarbons (Arenes)Aromatic Hydrocarbons (Arenes)• Generally less dense than water• Insoluble in water but soluble in
many organic solvents
New Way Chemistry for Hong Kong A-Level 3A
New Way Chemistry for Hong Kong A-Level Book 3A44
Aromatic Hydrocarbons (Arenes)Aromatic Hydrocarbons (Arenes)• PAHs : Polycyclic aromatic
hydrocarbons• Fused aromatic rings
New Way Chemistry for Hong Kong A-Level 3A
New Way Chemistry for Hong Kong A-Level Book 3A55
Aromatic Hydrocarbons (Arenes)Aromatic Hydrocarbons (Arenes)• No heteroatoms
NB
Not PAH
New Way Chemistry for Hong Kong A-Level 3A
New Way Chemistry for Hong Kong A-Level Book 3A66
Aromatic Hydrocarbons (Arenes)Aromatic Hydrocarbons (Arenes)• PAHs : Polycyclic aromatic
hydrocarbonsSources : - incomplete combustion of
Q.38 benzocyclobutadiene
New Way Chemistry for Hong Kong A-Level 3A
wood, coal, diesel, fat, or tobacco
New Way Chemistry for Hong Kong A-Level Book 3A77
PAHs : Polyaromatic hydrocarbons
Toxic and carcinogenicBenzo(a)pyrene : - first carcinogen discovered
New Way Chemistry for Hong Kong A-Level 3A
Found in : - tobacco smoke,- char-grilled food- burnt toast,- edible oils
New Way Chemistry for Hong Kong A-Level Book 3A88
Preparation of Preparation of BenzeneBenzene
New Way Chemistry for Hong Kong A-Level 3A
New Way Chemistry for Hong Kong A-Level Book 3A99
1. Destructive Distillation of Coal• Gives coal gas, ammoniacal
liquor, coal tar and coke as products
• The coal tar produced is a mixture of many organic compounds (mainly aromatic ones)
• benzene and methylbenzene can be obtained by fractional distillationNew Way Chemistry for Hong Kong A-Level 3A
New Way Chemistry for Hong Kong A-Level Book 3A1010
1. Destructive Distillation of Coal
A laboratory set-up of the destructive
distillation of coal
New Way Chemistry for Hong Kong A-Level 3A
New Way Chemistry for Hong Kong A-Level Book 3A1111
Industrial Industrial PreparationPreparation2. Catalytic trimerization of ethyne
HC CH3organonickel catalyst
70oC, under pressure
New Way Chemistry for Hong Kong A-Level 3A
New Way Chemistry for Hong Kong A-Level Book 3A1212
Industrial Industrial PreparationPreparation3. Catalytic Reforming of Petroleum• Converts alkanes and
cycloalkanes into aromatic hydrocarbons
C6H14 C6H6 + 4H2500 oC, 10 – 20
atm
Pt
New Way Chemistry for Hong Kong A-Level 3A
New Way Chemistry for Hong Kong A-Level Book 3A1313
Laboratory Laboratory SynthesisSynthesis
1. Decarboxylation of Sodium Salt of Benzoic Acid• When sodium benzoate is fused
with sodium hydroxide the carboxylate group is removed
volatileBenzene is separated by fractional distillation
New Way Chemistry for Hong Kong A-Level Book 3A1414
2. Reduction of Phenol• Passing phenol vapour over heated
zinc dust (reducing agent) produce benzene and zinc(II) oxide
Benzene is separated by fractional distillation
volatile
New Way Chemistry for Hong Kong A-Level Book 3A1515
Reactions of Reactions of BenzeneBenzene
New Way Chemistry for Hong Kong A-Level 3A
New Way Chemistry for Hong Kong A-Level Book 3A1616
Reactivity of Benzene
Unreactive towards addition reactions due tostabilization of the system by delocalization of -electrons
New Way Chemistry for Hong Kong A-Level 3A
New Way Chemistry for Hong Kong A-Level Book 3A1717
Reactivity of Benzene
Not oxidized by KMnO4
New Way Chemistry for Hong Kong A-Level 3A
New Way Chemistry for Hong Kong A-Level Book 3A1818
Reactivity of Benzene
Resistant to electrophilic addition at room conditions
Br2 / HBr / H2O
New Way Chemistry for Hong Kong A-Level 3A
New Way Chemistry for Hong Kong A-Level Book 3A1919
Reactivity of Benzene
Resistant to catalytic hydrogenation
New Way Chemistry for Hong Kong A-Level 3A
New Way Chemistry for Hong Kong A-Level Book 3A2020
Addition reactions occur only under drastic conditions.
excess H2, high T&P
Ni or Pt or Pd
New Way Chemistry for Hong Kong A-Level 3A
New Way Chemistry for Hong Kong A-Level Book 3A21New Way Chemistry for Hong Kong A-Level
3A21
Br2 / HBr / H2O
Incomplete combustiondue to high C content
No reaction when cold.slow sulphonation whenheated.Occur only
under drastic conditions
No reaction
New Way Chemistry for Hong Kong A-Level Book 3A2222
The -electron cloud is susceptible to electrophilic attack.Substitution is preferred to addition since the former retains aromaticity.Electrophilic aromatic substitution (SE)
New Way Chemistry for Hong Kong A-Level 3A
New Way Chemistry for Hong Kong A-Level Book 3A23New Way Chemistry for Hong Kong A-Level
3A23
X
X : Cl, Br
(Halogenation)
NO2 (Nitration)
SO3H (Sulphonation)
R (Alkylation)
C
R
O
(Acylation)
conc. H2SO4 or fuming H2SO4
R
X
O
New Way Chemistry for Hong Kong A-Level Book 3A2424
Electrophilic Aromatic Substitution Electrophilic Aromatic Substitution ReactionsReactions
E+ : electrophile
New Way Chemistry for Hong Kong A-Level 3A
New Way Chemistry for Hong Kong A-Level Book 3A2525
General Reaction MechanismStep 1:
New Way Chemistry for Hong Kong A-Level 3A
• Rate determining step
New Way Chemistry for Hong Kong A-Level Book 3A2626
General Reaction Mechanism• Stabilized by delocalization of
electrons
New Way Chemistry for Hong Kong A-Level 3A
+
New Way Chemistry for Hong Kong A-Level Book 3A2727
General Reaction MechanismStep 2:
New Way Chemistry for Hong Kong A-Level 3A
• The carbocation loses a hydrogen ion forms the substitution product
New Way Chemistry for Hong Kong A-Level Book 3A28New Way Chemistry for Hong Kong A-Level
3A28
Cl
Br
+ HCl (slow)
+ HBr (fast)
No apparent reation
1. Halogenation
Catalysts : AlCl3, FeCl3 or FeBr3
New Way Chemistry for Hong Kong A-Level Book 3A2929
1. Halogenation - MechanismStep 1:• The catalyst (FeBr3) combines with
bromine to give a complex
Br BrFeBr3
Br [FeBr4]
New Way Chemistry for Hong Kong A-Level 3A
New Way Chemistry for Hong Kong A-Level Book 3A3030
Step 2:
Br [FeBr]
Br
H
+
Br
H
Br
H
Stabilized by delocalization of -electronsNew Way Chemistry for Hong Kong A-Level 3A
• Formation of carbocation intermediate
• Rate determining step
New Way Chemistry for Hong Kong A-Level Book 3A3131
Step 3:• The catalyst (FeBr3) is regenerated
Fumes of HBr(g) are produced, indicating substitution rather than addition has occurred.
New Way Chemistry for Hong Kong A-Level 3A
New Way Chemistry for Hong Kong A-Level Book 3A3232
2. Nitration• Benzene reacts readily with a
mixture of conc. HNO3 and conc. H2SO4
• Conc. H2SO4 increases the rate of reaction by increasing the concentration of the electrophile, NO2
+
New Way Chemistry for Hong Kong A-Level 3A
New Way Chemistry for Hong Kong A-Level Book 3A3333
H2SO4 + N
O
O
HO O N
O
O
H
H
O N O + H2O
acid base
electrophile
2HNO3 NO3 + H2O + NO2
+
New Way Chemistry for Hong Kong A-Level 3A
New Way Chemistry for Hong Kong A-Level Book 3A3434
NO2
conc. HNO3
conc. H2SO4, 110oC
NO2
NO2NO2O2N
NO2
conc. HNO3
conc. H2SO4, 95oC
NO2
NO2
Optional New Way Chemistry for Hong Kong A-Level 3A
meta-directing
New Way Chemistry for Hong Kong A-Level Book 3A35
NO O
O N O
New Way Chemistry for Hong Kong A-Level 3A
35
Q.39
H2SO4 + HNO3 NO2+ + H2O +
HSO4
New Way Chemistry for Hong Kong A-Level Book 3A36
NO O
NO O
NO O
New Way Chemistry for Hong Kong A-Level Book 3A37
NO O
H
HSO4
NO2
+ H2SO4
New Way Chemistry for Hong Kong A-Level Book 3A3838
3. Sulphonation• Benzene reacts with fuming
sulphuric acid at room temp form benzenesulphonic acid
+
(H2SO4 + SO3)
New Way Chemistry for Hong Kong A-Level 3A
New Way Chemistry for Hong Kong A-Level Book 3A3939
3. Sulphonation• Sulphonation is a reversible process
• By heating an aqueous solution of benzenesulphonic acid to above 100 oC benzene and sulphuric acid are formed
New Way Chemistry for Hong Kong A-Level 3A
heat
New Way Chemistry for Hong Kong A-Level Book 3A40
SH
O
O
O
New Way Chemistry for Hong Kong A-Level 3A
40
Q.40
H2SO4 + H2SO4 SO3 + H3O+ + HSO4
S
O
O O
New Way Chemistry for Hong Kong A-Level Book 3A41
SH
O
O
O SH
O
O
O SH
O
O
O
New Way Chemistry for Hong Kong A-Level Book 3A42
HSO4
SO3SH
O
O
O
H+
SO3H
+ H2SO4
New Way Chemistry for Hong Kong A-Level Book 3A4343
4. Friedel-Crafts Alkylation• When benzene is warmed with a
haloalkane in the presence of AlCl3 as a catalyst alkylbenzene is formed
New Way Chemistry for Hong Kong A-Level 3A
New Way Chemistry for Hong Kong A-Level Book 3A4444
Important starting step in the manufacture of styrene, phenol and detergents
4. Friedel-Crafts Alkylation
New Way Chemistry for Hong Kong A-Level 3A
The alkyl group introduced activates the ring towards further alkylation by +ve I-effect. Friedel-Crafts alkylation is not a good way to prepare alkylbenzene.
New Way Chemistry for Hong Kong A-Level Book 3A4545 New Way Chemistry for Hong Kong A-Level 3A
C Cl
R
O
AlCl3
CR O
CH2
R
Hg/Zn
conc. HCl
Friedel-Craft acylation
Clemensen reduction
deactivating
+
New Way Chemistry for Hong Kong A-Level Book 3A46
Devise a reaction pathway of not more than four steps for the following conversion.
COOH CH3
46
6B 09/07/2011
New Way Chemistry for Hong Kong A-Level Book 3A47
CH3
COOH
sodalime
fusion
C Cl
H
O
AlCl3
CO H
47
New Way Chemistry for Hong Kong A-Level Book 3A48New Way Chemistry for Hong Kong A-Level
3A48
Chlorination Bromination or Friedel-Craft reaction
Soda lime to absorb HBr or HCl fumes
Br2, RCl or RCOCl
or AlCl3
New Way Chemistry for Hong Kong A-Level Book 3A49New Way Chemistry for Hong Kong A-Level
3A49
Q.41
CH3Cl + AlCl3 [CH3]+
[AlCl4]
electrophile
New Way Chemistry for Hong Kong A-Level Book 3A50
C
H
H H
CH3
H
two more structures
AlCl4
CH3
+ HCl + AlCl3
New Way Chemistry for Hong Kong A-Level Book 3A51New Way Chemistry for Hong Kong A-Level
3A51
Q.42(a)
2C6H6 + X C6H5CH2C6H5 + 2HClAlCl3
X : CH2Cl2
New Way Chemistry for Hong Kong A-Level Book 3A52New Way Chemistry for Hong Kong A-Level
3A52
-CH2Cl deactivate the ringSusceptibility to SE reaction :
>
CH2Cl
CH2Cl2
AlCl3
(excess)
CH2Cl
CH2
AlCl3
New Way Chemistry for Hong Kong A-Level Book 3A53New Way Chemistry for Hong Kong A-Level
3A53
Q.42(b)
3C6H6 + Y (C6H5)3CH + 3HClAlCl3
Y : CHCl3
New Way Chemistry for Hong Kong A-Level Book 3A54New Way Chemistry for Hong Kong A-Level
3A54
CHCl3
AlCl3
(excess)
CHCl2
CHCl
C H
AlCl3
AlCl3
New Way Chemistry for Hong Kong A-Level Book 3A55New Way Chemistry for Hong Kong A-Level
3A55
Q.42(c)
2C6H6 + Z C6H5CH2CH2C6H5 + 2HClAlCl3
Z : CH2ClCH2Cl
New Way Chemistry for Hong Kong A-Level Book 3A56New Way Chemistry for Hong Kong A-Level
3A56
AlCl3
(excess)
AlCl3
ClH2C CH2Cl
ClH2C
New Way Chemistry for Hong Kong A-Level Book 3A57New Way Chemistry for Hong Kong A-Level
3A57
1. Coal tarFractionaldistillation
CH3
2. PetroleumFractionaldistillation
CH3
catalyst
high T & P
CH3
+ 3H2
Industrial preparation of toluene
New Way Chemistry for Hong Kong A-Level Book 3A58New Way Chemistry for Hong Kong A-Level
3A58
Laboratory Preparation of Methylbenzene1. Friedel-Crafts acylation of benzene followed by Clemensen reduction.
2. Friedel-Crafts alkylation of benzene is not recommended as further alkylation will take place giving a mixture of alkylbenzenes that are difficult to be
separated.
New Way Chemistry for Hong Kong A-Level Book 3A5959
Reactions of methylbenzene and Other Alkylbenzenes
1. Electrophilic aromatic substitution rxsmore susceptible to electrophilic attacks ∵ alkyl groups activate the ring by
positive inductive effect.
New Way Chemistry for Hong Kong A-Level Book 3A60New Way Chemistry for Hong Kong A-Level
3A60
2. Reactions of the side chain(a) Free radical substitution vs electrophilic substitution at the ring
CH3
CH2Cl CHCl2 CCl3
+ +
CH3CH3
Cl
Cl
+
Free radical substitution
Electrophilic substitution
New Way Chemistry for Hong Kong A-Level Book 3A61New Way Chemistry for Hong Kong A-Level
3A61
Benzylic hydrogens are much more susceptible to free radical substitution than hydrogens at other positions.
H2CCH3
CHCH3
Br
H2CCH2Br
CCH3
BrBr
+
H2CCHBr2 H2C
CBr3
+ +
Major products
New Way Chemistry for Hong Kong A-Level Book 3A62New Way Chemistry for Hong Kong A-Level
3A62
(b) Oxidation at the benzylic carbon
CHR
R
CR3
COOH
CH3
H2C
R
Absence of benzylic
H
New Way Chemistry for Hong Kong A-Level Book 3A63New Way Chemistry for Hong Kong A-Level 3A63
If alkaline KMnO4 is used, the resulting mixture must be acidified in order to obtain the benzoic acid.
CH3
KMnO4 / OH- H+
COO- COOH
CH3
1. KMnO4 / OH-, heat
2. H+
COOH
heat
Or,
New Way Chemistry for Hong Kong A-Level Book 3A6464
H3C
CH3
CH3
CH3
CH2CH3
COOH
COOH
COOH
COOH
COOH
COOH
COOH
CH3
CH3
m.p. 231oC m.p. 348oC m.p. 300oC m.p. 122oC
b.p. 144oC b.p. 139oC b.p. 138oC b.p. 136oC
alkylbenzenes with very close boiling points
acids with different melting points
Structural determination of isomeric alkylbenzene
New Way Chemistry for Hong Kong A-Level 3A
C8H10
New Way Chemistry for Hong Kong A-Level Book 3A6565
H3C
CH3
CH3
CH3
CH2CH3
COOH
COOH
COOH
COOH
COOH
COOH
COOH
CH3
CH3
m.p. 231oC m.p. 348oC m.p. 300oC m.p. 122oC
b.p. 144oC b.p. 139oC b.p. 138oC b.p. 136oC
alkylbenzenes with very close boiling points
acids with different melting points
Structural determination of isomeric alkylbenzene
New Way Chemistry for Hong Kong A-Level 3A
New Way Chemistry for Hong Kong A-Level Book 3A66
Q.43(a)COOH
1. MnO4- / OH-
2. H++
HOC
CH3
O
New Way Chemistry for Hong Kong A-Level 3A66
New Way Chemistry for Hong Kong A-Level Book 3A67
Q.43(b)COOH
COOH
1. MnO4- / OH-
2. H++ CO2
New Way Chemistry for Hong Kong A-Level 3A67
Terminal alkene gives CO2
COOH
COOH
1. MnO4- / OH-
2. H+
COOH
1. MnO4- / OH-
2. H+HOOC
+ H2O
New Way Chemistry for Hong Kong A-Level Book 3A68
Q.43(b)
New Way Chemistry for Hong Kong A-Level 3A68
COOH1. MnO4
- / OH-
2. H+
New Way Chemistry for Hong Kong A-Level Book 3A69
Q.43(b)
COOH
COOH
1. MnO4- / OH-
2. H+
New Way Chemistry for Hong Kong A-Level 3A69
COOH1. MnO4
- / OH-
2. H+
COOH
New Way Chemistry for Hong Kong A-Level Book 3A70
Q.43(b)
New Way Chemistry for Hong Kong A-Level 3A70
COOH1. MnO4
- / OH-
2. H+
COOH1. MnO4
- / OH-
2. H+
New Way Chemistry for Hong Kong A-Level Book 3A71
Q.43(c)
1. MnO4- / OH-
2. H++ CO2
O
71 New Way Chemistry for Hong Kong A-Level 3A
+ H2O
New Way Chemistry for Hong Kong A-Level Book 3A7272
The END
New Way Chemistry for Hong Kong A-Level 3A
New Way Chemistry for Hong Kong A-Level Book 3A73New Way Chemistry for Hong Kong A-Level
3A73
29.2 Nomenclature of the Derivatives of Benzene (SB p.191)
Draw the structural formula for each of the following compounds:(a) 1,3,5-Trichlorobenzene(b) 2,5-Dibromophenol(c) 2,4-Dinitrobenzoic acid Answer
Back
(a) (b) (c)
New Way Chemistry for Hong Kong A-Level Book 3A74New Way Chemistry for Hong Kong A-Level
3A74
29.2 Nomenclature of the Derivatives of Benzene (SB p.192)
Give the IUPAC name for each of the following compounds:(a)
(b)
Answer
(a) 1,2-Dimethylbenzene(b) 1-Methyl-2-nitrobenzene or 2-
nitrotoluene
New Way Chemistry for Hong Kong A-Level Book 3A75New Way Chemistry for Hong Kong A-Level
3A75
29.2 Nomenclature of the Derivatives of Benzene (SB p.192)
Give the IUPAC name for each of the following compounds:(c)
(d)
Answer
Back
(c) 3-Bromo-5-chlorobenzoic acid(d) 4-Bromo-2,6-dinitrophenol
New Way Chemistry for Hong Kong A-Level Book 3A76New Way Chemistry for Hong Kong A-Level
3A76
29.3 Structure of Benzene and Aromaticity (SB p.195)
The basic structural requirement for aromatic compounds is that the molecule must be planar,cyclic and with (4n + 2) electrons delocalized in
the ring. n must be a natural number (i.e. n = 1, 2, 3, and so on).
There are aromatic compounds without benzene ring. An example is the 1,3-cyclopentadienyl anion. Can you draw its structure and explain its aromaticity?
Answer
New Way Chemistry for Hong Kong A-Level Book 3A77New Way Chemistry for Hong Kong A-Level
3A77
29.3 Structure of Benzene and Aromaticity (SB p.195)
Back
Cyclopentadienyl anion is an aromatic anion. It has six π electrons delocalized over a completely conjugated planar monocyclic system of five sp2 hybridized carbon atoms.
Cyclopentadienyl anion
New Way Chemistry for Hong Kong A-Level Book 3A78New Way Chemistry for Hong Kong A-Level
3A78
29.4 Physical Properties of Aromatic Hydrocarbons (SB p.197)
PAHs are formed from partial combustion and pyrolysis of aromatic compounds. They are in
common occurrence in our environment. List some important uses of aromatic hydrocarbons and how
they release PAHs to our environment.Answer
New Way Chemistry for Hong Kong A-Level Book 3A79New Way Chemistry for Hong Kong A-Level
3A79
29.4 Physical Properties of Aromatic Hydrocarbons (SB p.197)
Aromatic hydrocarbons are the raw materials for the manufacture of monomers and plasticizers in polymers, commonly used as solvents and important constituents of lead-free gasoline.Incomplete combustion and pyrolysis process favour the production of PAHs. These compounds are encountered abundantly in the atmosphere, soil and elsewhere in the environment from sources that include engine exhaust, wood stove smoke, cigarette smoke and charbroiled food. Coal tar and petroleum residues such as road and roofing asphalt have high levels of PAHs.
Back
New Way Chemistry for Hong Kong A-Level Book 3A80New Way Chemistry for Hong Kong A-Level
3A80
29.6 Reactions of Benzene (SB p.203)
Complete each of the following by supplying the missing reactant or product as indicated by the question mark:(a)
(b)
(c)
Answer
Back
(a)
(b) conc. H2SO4, conc. HNO3
(c) fuming H2SO4
New Way Chemistry for Hong Kong A-Level Book 3A81New Way Chemistry for Hong Kong A-Level
3A81
29.6 Reactions of Benzene (SB p.203)
(a) One mole of benzene reacts with three moles of chlorine under special conditions. What are the conditions required for the reaction?
(a) UV radiation or diffuse sunlight must be present for the free radical addition reaction to take place.
Answer
New Way Chemistry for Hong Kong A-Level Book 3A82New Way Chemistry for Hong Kong A-Level
3A82
29.6 Reactions of Benzene (SB p.203)
(b) Draw the structure of the reaction product in (a). Answer(b)
New Way Chemistry for Hong Kong A-Level Book 3A83New Way Chemistry for Hong Kong A-Level
3A83
29.6 Reactions of Benzene (SB p.203)
(c) Methylbenzene undergoes two different types of chlorination reaction by different mechanisms. Compare the two different types of chlorination reaction in terms of reaction conditions as well as the products formed. Answer
New Way Chemistry for Hong Kong A-Level Book 3A84New Way Chemistry for Hong Kong A-Level
3A84
29.6 Reactions of Benzene (SB p.203)
(c) The two different types of chlorination reaction of methylbenzene are:Type I: free radical substitution reaction
Type II: electrophilic aromatic substitution reaction
Back
New Way Chemistry for Hong Kong A-Level Book 3A85New Way Chemistry for Hong Kong A-Level
3A85
Reaction Cyclohexane (a saturated
alicyclic hydrocarbon)
Cyclohexene (an unsaturated
alicyclic hydrocarbon)
Methylbenzene (an aromatic hydrocarbon)
Action of bromine in 1,1,1-trichloro-ethane (in dark)
No reaction Bromine is decolourized and no hydrogen bromide is evolved
No reaction with bromine alone. In the presence of iron(III) bromide, bromine is decolourized and hydrogen bromide fumes are evolved
Comparison of some reactions of cyclohexane, cyclohexene and methylbenzene
New Way Chemistry for Hong Kong A-Level Book 3A86New Way Chemistry for Hong Kong A-Level
3A86
Reaction Cyclohexane (a saturated
alicyclic hydrocarbon)
Cyclohexene (an unsaturated
alicyclic hydrocarbon)
Methylbenzene (an aromatic hydrocarbon)
Action of hydrogen (with nickel catalyst)
No reaction One mole of cyclohexene reacts with one mole of hydrogen at room temperature
One mole of methylbenzene reacts with three moles of hydrogen at high temperature
Comparison of some reactions of cyclohexane, cyclohexene and methylbenzene
New Way Chemistry for Hong Kong A-Level Book 3A87New Way Chemistry for Hong Kong A-Level
3A87
Reaction Cyclohexane (a saturated
alicyclic hydrocarbon)
Cyclohexene (an unsaturated
alicyclic hydrocarbon)
Methylbenzene (an aromatic hydrocarbon)
Action of acidified potassium manganate(VII)
No reaction Acidified potassium manganate(VII) solution is decolourized
No reaction
Comparison of some reactions of cyclohexane, cyclohexene and methylbenzene
New Way Chemistry for Hong Kong A-Level Book 3A88New Way Chemistry for Hong Kong A-Level
3A88
Reaction Cyclohexane (a saturated
alicyclic hydrocarbon)
Cyclohexene (an unsaturated
alicyclic hydrocarbon)
Methylbenzene (an aromatic hydrocarbon)
Action of concentrated nitric acid and concentrated sulphuric acid
No reaction Cyclohexene is oxidized and the colour darkens
A yellow liquid is formed
Comparison of some reactions of cyclohexane, cyclohexene and methylbenzene